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van Lutterveld R, Chowdhury A, Ingram DM, Sacchet MD. Neurophenomenological Investigation of Mindfulness Meditation "Cessation" Experiences Using EEG Network Analysis in an Intensively Sampled Adept Meditator. Brain Topogr 2024:10.1007/s10548-024-01052-4. [PMID: 38703334 DOI: 10.1007/s10548-024-01052-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Accepted: 04/12/2024] [Indexed: 05/06/2024]
Abstract
Mindfulness meditation is a contemplative practice that is informed by Buddhism. It has been proven effective for improving mental and physical health in clinical and non-clinical contexts. To date, mainstream dialogue and scientific research on mindfulness has focused primarily on short-term mindfulness training and applications of mindfulness for reducing stress. Understanding advanced mindfulness practice has important implications for mental health and general wellbeing. According to Theravada Buddhist meditation, a "cessation" event is a dramatic experience of profound clarity and equanimity that involves a complete discontinuation in experience, and is evidence of mastery of mindfulness meditation. Thirty-seven cessation events were captured in a single intensively sampled advanced meditator (over 6,000 h of retreat mindfulness meditation training) while recording electroencephalography (EEG) in 29 sessions between November 12, 2019 and March 11, 2020. Functional connectivity and network integration were assessed from 40 s prior to cessations to 40 s after cessations. From 21 s prior to cessations there was a linear decrease in large-scale functional interactions at the whole-brain level in the alpha band. In the 40 s following cessations these interactions linearly returned to prior levels. No modulation of network integration was observed. The decrease in whole-brain functional connectivity was underlain by frontal to left temporal and to more posterior decreases in connectivity, while the increase was underlain by wide-spread increases in connectivity. These results provide neuroscientific evidence of large-scale modulation of brain activity related to cessation events that provides a foundation for future studies of advanced meditation.
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Affiliation(s)
- Remko van Lutterveld
- Brain Research and Innovation Centre and Department of Psychiatry, Ministry of Defence and University Medical Center, Utrecht, The Netherlands.
| | - Avijit Chowdhury
- Center for Depression, Anxiety, and Stress Research, McLean Hospital, Harvard Medical School, Belmont, MA, USA
| | | | - Matthew D Sacchet
- Center for Depression, Anxiety, and Stress Research, McLean Hospital, Harvard Medical School, Belmont, MA, USA
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Peill J, Marguilho M, Erritzoe D, Barba T, Greenway KT, Rosas F, Timmermann C, Carhart-Harris R. Psychedelics and the 'inner healer': Myth or mechanism? J Psychopharmacol 2024; 38:417-424. [PMID: 38605658 DOI: 10.1177/02698811241239206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
BACKGROUND Reference to an intrinsic healing mechanism or an 'inner healer' is commonplace amongst psychedelic drug-using cultures. The 'inner healer' refers to the belief that psychedelic compounds, plants or concoctions have an intrinsically regenerative action on the mind and brain, analogous to intrinsic healing mechanisms within the physical body, for example, after sickness or injury. AIMS Here, we sought to test and critique this idea by devising a single subjective rating item pertaining to perceived 'inner healing' effects. METHODS The item was issued to 59 patients after a single high (25 mg, n = 30) or 'placebo' (1 mg, n = 29) dose of psilocybin in a double-blind randomised controlled trial of psilocybin for depression. RESULTS Inner healer scores were higher after the high versus placebo dose of psilocybin (t = 3.88, p < 0.001). Within the high-dose sub-sample only, inner healer scores predicted improved depressive symptomatology at 2 weeks post-dosing. CONCLUSIONS The principle of activating inner healing mechanisms via psychedelics is scientifically nascent; however, this study takes a positivist and pragmatic step forward, asking whether it warrants further examination.
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Affiliation(s)
- Joseph Peill
- Division of Psychiatry, Department of Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Miriam Marguilho
- Division of Psychiatry, Lisbon Psychiatric Hospital Centre, Lisbon, Portugal
| | - David Erritzoe
- Division of Psychiatry, Department of Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Tommaso Barba
- Division of Psychiatry, Department of Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Kyle T Greenway
- Division of Psychiatry, Lisbon Psychiatric Hospital Centre, Lisbon, Portugal
- Faculty of Medicine, Department of Psychiatry, McGill University, Ludmer Research and Training Building, Montréal, QC, Canada
- Lady Davis Institute, Jewish General Hospital, Montréal, QC, Canada
| | - Fernando Rosas
- Division of Psychiatry, Department of Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
- Centre for Complexity Science, Imperial College London, London, UK
- Department of Informatics, University of Sussex, Brighton, UK
- Centre for Eudaimonia and Human Flourishing, University of Oxford, Oxford, UK
| | - Christopher Timmermann
- Division of Psychiatry, Department of Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Robin Carhart-Harris
- Division of Psychiatry, Department of Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
- Departments of Neurology and Psychiatry, Carhart-Harris Lab, University of California San Francisco, San Francisco, CA, USA
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Lewis EC, Jaeger A, Girn M, Omene E, Brendle M, Argento E. Exploring psychedelic-assisted therapy in the treatment of functional seizures: A review of underlying mechanisms and associated brain networks. J Psychopharmacol 2024; 38:407-416. [PMID: 38654554 DOI: 10.1177/02698811241248395] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Functional seizures (FS), the most common subtype of functional neurological disorder (FND), cause serious neurological disability and significantly impact quality of life. Characterized by episodic disturbances of functioning that resemble epileptic seizures, FS coincide with multiple comorbidities and are treated poorly by existing approaches. Novel treatment approaches are sorely needed. Notably, mounting evidence supports the safety and efficacy of psychedelic-assisted therapy (PAT) for several psychiatric conditions, motivating investigations into whether this efficacy also extends to neurological disorders. Here, we synthesize past empirical findings and frameworks to construct a biopsychosocial mechanistic argument for the potential of PAT as a treatment for FS. In doing so, we highlight FS as a well-defined cohort to further understand the large-scale neural mechanisms underpinning PAT. Our synthesis is guided by a complexity science perspective which we contend can afford unique mechanistic insight into both FS and PAT, as well as help bridge these two domains. We also leverage this perspective to propose a novel analytic roadmap to identify markers of FS diagnostic specificity and treatment success. This endeavor continues the effort to bridge clinical neurology with psychedelic medicine and helps pave the way for a new field of psychedelic neurology.
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Affiliation(s)
- Evan Cole Lewis
- Hospital for Sick Children, Department of Pediatrics, University of Toronto, Toronto, ON, Canada
| | | | - Manesh Girn
- Neuroscape, Department of Neurology, University of California San Francisco, San Francisco, CA, USA
| | | | - Madeline Brendle
- Numinus Wellness Inc., Vancouver, BC, Canada
- Health Outcomes Division, College of Pharmacy, University of Texas at Austin, Austin, TX, USA
| | - Elena Argento
- Numinus Wellness Inc., Vancouver, BC, Canada
- Department of Psychology, University of British Columbia, Kelowna, BC, Canada
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Hilal FF, Jeanblanc J, Deschamps C, Naassila M, Pierrefiche O, Ben Hamida S. Epigenetic drugs and psychedelics as emerging therapies for alcohol use disorder: insights from preclinical studies. J Neural Transm (Vienna) 2024; 131:525-561. [PMID: 38554193 DOI: 10.1007/s00702-024-02757-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 02/22/2024] [Indexed: 04/01/2024]
Abstract
Alcohol use disorder (AUD) is a public health issue that affects millions of people worldwide leading to physical, mental and socio-economic consequences. While current treatments for AUD have provided relief to individuals, their effectiveness on the long term is often limited, leaving a number of affected individuals without sustainable solutions. In this review, we aim to explore two emerging approaches for AUD: psychedelics and epigenetic drugs (i.e., epidrugs). By examining preclinical studies, different animal species and procedures, we delve into the potential benefits of each of these treatments in terms of addictive behaviors (alcohol drinking and seeking, motivation to drink alcohol and prevention of relapse). Because psychedelics and epidrugs may share common and complementary mechanisms of action, there is an exciting opportunity for exploring synergies between these approaches and their parallel effectiveness in treating AUD and the diverse associated psychiatric conditions.
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Affiliation(s)
- Fahd François Hilal
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France
| | - Jerome Jeanblanc
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France
| | - Chloé Deschamps
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France
| | - Mickael Naassila
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France.
| | - Olivier Pierrefiche
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France
| | - Sami Ben Hamida
- INSERM UMR 1247-Research Group on Alcohol and Pharmacodependences (GRAP), Université de Picardie Jules Verne, Chemin du Thil - Centre Universitaire de Recherche en Santé, 80025, Amiens, France.
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Erritzoe D, Barba T, Spriggs MJ, Rosas FE, Nutt DJ, Carhart-Harris R. Effects of discontinuation of serotonergic antidepressants prior to psilocybin therapy versus escitalopram for major depression. J Psychopharmacol 2024; 38:458-470. [PMID: 38520045 DOI: 10.1177/02698811241237870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/25/2024]
Abstract
BACKGROUND There is growing evidence for the therapeutic effects of the psychedelic drug psilocybin for major depression. However, due to the lack of safety data on combining psilocybin with selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) and concerns that there may be a negative interaction on efficacy, participants enrolling in psychedelic trials are usually required to discontinue SNRI/SNRIs prior to enrolling. AIMS Using data from a recent clinical trial examining the comparative efficacy the psychedelic drug psilocybin (P) combined with approximately 20 h of psychological support to a 6-week (daily) course of the SSRI escitalopram plus matched psychological support for major depressive disorder, we explored the effects of discontinuing SSRI/SNRIs prior to study enrolment on study outcomes. METHODS Exploratory post hoc analyses using linear mixed effects model were performed to investigate the discontinuation effect on various validated depression symptom severity scales and well-being. The impact of SSRI/SNRIs discontinuation on the acute psychedelic experience was also explored. RESULTS/OUTCOMES In the psilocybin group, there was a reduced treatment effect on all outcome measures for SSRI/SNRIs discontinuers compared with unmedicated patients at trial entry. However, no effects of discontinuation on measures of the acute psychedelic experience were found. CONCLUSION Discontinuation of SSRI/SNRIs before psilocybin might diminish response to treatment; however, as we did not test SSRI/SNRI continuation in our trial, we cannot infer such causation. Moreover, the exploratory nature of the analyses makes them hypothesis generating, and not confirmatory. A controlled trial of SSRI/SNRI discontinuation versus continuation prior to psilocybin is urgently required.
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Affiliation(s)
- David Erritzoe
- Division of Psychiatry, Department Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Tommaso Barba
- Division of Psychiatry, Department Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Meg J Spriggs
- Division of Psychiatry, Department Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Fernando E Rosas
- Division of Psychiatry, Department Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
- Department of Informatics, University of Sussex, Brighton, UK
| | - David J Nutt
- Division of Psychiatry, Department Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Robin Carhart-Harris
- Division of Psychiatry, Department Brain Sciences, Centre for Psychedelic Research, Imperial College London, London, UK
- Departments of Neurology and Psychiatry, University of California San Francisco, San Francisco, CA, USA
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Tipado Z, Kuypers KPC, Sorger B, Ramaekers JG. Visual hallucinations originating in the retinofugal pathway under clinical and psychedelic conditions. Eur Neuropsychopharmacol 2024; 85:10-20. [PMID: 38648694 DOI: 10.1016/j.euroneuro.2024.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 04/11/2024] [Accepted: 04/13/2024] [Indexed: 04/25/2024]
Abstract
Psychedelics like LSD (Lysergic acid diethylamide) and psilocybin are known to modulate perceptual modalities due to the activation of mostly serotonin receptors in specific cortical (e.g., visual cortex) and subcortical (e.g., thalamus) regions of the brain. In the visual domain, these psychedelic modulations often result in peculiar disturbances of viewed objects and light and sometimes even in hallucinations of non-existent environments, objects, and creatures. Although the underlying processes are poorly understood, research conducted over the past twenty years on the subjective experience of psychedelics details theories that attempt to explain these perceptual alterations due to a disruption of communication between cortical and subcortical regions. However, rare medical conditions in the visual system like Charles Bonnet syndrome that cause perceptual distortions may shed new light on the additional importance of the retinofugal pathway in psychedelic subjective experiences. Interneurons in the retina called amacrine cells could be the first site of visual psychedelic modulation and aid in disrupting the hierarchical structure of how humans perceive visual information. This paper presents an understanding of how the retinofugal pathway communicates and modulates visual information in psychedelic and clinical conditions. Therefore, we elucidate a new theory of psychedelic modulation in the retinofugal pathway.
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Affiliation(s)
- Zeus Tipado
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands; Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands.
| | - Kim P C Kuypers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands
| | - Bettina Sorger
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands
| | - Johannes G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands
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Maia JM, de Oliveira BSA, Branco LGS, Soriano RN. Therapeutic potential of psychedelics: History, advancements, and unexplored frontiers. Prog Neuropsychopharmacol Biol Psychiatry 2024; 131:110951. [PMID: 38307161 DOI: 10.1016/j.pnpbp.2024.110951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Revised: 12/20/2023] [Accepted: 01/18/2024] [Indexed: 02/04/2024]
Abstract
Psychedelics (serotonergic hallucinogens) are psychoactive substances that can alter perception and mood, and affect cognitive functions. These substances activate 5-HT2A receptors and may exert therapeutic effects. Some of the disorders for which psychedelic-assisted therapy have been studied include depression, addiction, anxiety and post-traumatic stress disorder. Despite the increasing number of studies reporting clinical effectiveness, with fewer negative symptoms and, additionally, minimal side effects, questions remain to be explored in the field of psychedelic medicine. Although progress has been achieved, there is still little understanding of the relationship among human brain and the modulation induced by these drugs. The present article aimed to describe, review and highlight the most promising findings in the literature regarding the (putative) therapeutic effects of psychedelics.
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Affiliation(s)
- Juliana Marino Maia
- Department of Medicine, Federal University of Juiz de Fora, Governador Valadares, MG 35032-620, Brazil
| | | | - Luiz G S Branco
- Department of Basic and Oral Biology, School of Dentistry of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP 14040-904, Brazil; Department of Physiology, Medical School of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP 14040-900, Brazil.
| | - Renato Nery Soriano
- Division of Physiology and Biophysics, Department of Basic Life Sciences, Federal University of Juiz de Fora, Governador Valadares, MG 35020-360, Brazil
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Armstrong M, Castellanos J, Christie D. Chronic pain as an emergent property of a complex system and the potential roles of psychedelic therapies. Front Pain Res (Lausanne) 2024; 5:1346053. [PMID: 38706873 PMCID: PMC11066302 DOI: 10.3389/fpain.2024.1346053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Accepted: 04/02/2024] [Indexed: 05/07/2024] Open
Abstract
Despite research advances and urgent calls by national and global health organizations, clinical outcomes for millions of people suffering with chronic pain remain poor. We suggest bringing the lens of complexity science to this problem, conceptualizing chronic pain as an emergent property of a complex biopsychosocial system. We frame pain-related physiology, neuroscience, developmental psychology, learning, and epigenetics as components and mini-systems that interact together and with changing socioenvironmental conditions, as an overarching complex system that gives rise to the emergent phenomenon of chronic pain. We postulate that the behavior of complex systems may help to explain persistence of chronic pain despite current treatments. From this perspective, chronic pain may benefit from therapies that can be both disruptive and adaptive at higher orders within the complex system. We explore psychedelic-assisted therapies and how these may overlap with and complement mindfulness-based approaches to this end. Both mindfulness and psychedelic therapies have been shown to have transdiagnostic value, due in part to disruptive effects on rigid cognitive, emotional, and behavioral patterns as well their ability to promote neuroplasticity. Psychedelic therapies may hold unique promise for the management of chronic pain.
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Affiliation(s)
- Maya Armstrong
- Department of Family & Community Medicine, University of New Mexico, Albuquerque, NM, United States
| | - Joel Castellanos
- Division of Pain Medicine, Department of Anesthesiology, University of California, San Diego, CA, United States
| | - Devon Christie
- Department of Medicine, University of British Columbia, Vancouver, BC, Canada
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Sloshower J, Zeifman RJ, Guss J, Krause R, Safi-Aghdam H, Pathania S, Pittman B, D'Souza DC. Psychological flexibility as a mechanism of change in psilocybin-assisted therapy for major depression: results from an exploratory placebo-controlled trial. Sci Rep 2024; 14:8833. [PMID: 38632313 PMCID: PMC11024097 DOI: 10.1038/s41598-024-58318-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Accepted: 03/27/2024] [Indexed: 04/19/2024] Open
Abstract
Several phase II studies have demonstrated that psilocybin-assisted therapy shows therapeutic potential across a spectrum of neuropsychiatric conditions, including major depressive disorder (MDD). However, the mechanisms underlying its often persisting beneficial effects remain unclear. Observational research suggests that improvements in psychological flexibility may mediate therapeutic effects. However, no psychedelic trials to date have substantiated this finding in a clinical sample. In an exploratory placebo-controlled, within-subject, fixed-order study, individuals with moderate to severe MDD were administered placebo (n = 19) followed by psilocybin (0.3 mg/kg) (n = 15) 4 weeks later. Dosing sessions were embedded within a manualized psychotherapy that incorporated principles of Acceptance and Commitment Therapy. Depression severity, psychological flexibility, mindfulness, and values-congruent living were measured over a 16-weeks study period. Psychological flexibility, several facets of mindfulness, and values-congruent living significantly improved following psilocybin and were maintained through week 16. Additionally, improvements in psychological flexibility and experiential acceptance were strongly associated with reductions in depression severity following psilocybin. These findings support the theoretical premise of integrating psilocybin treatment with psychotherapeutic platforms that target psychological flexibility and add to emerging evidence that increasing psychological flexibility may be an important putative mechanism of change in psilocybin-assisted therapy for MDD and potentially, other mental health conditions.
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Affiliation(s)
- Jordan Sloshower
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA.
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA.
- West Rock Wellness PLLC, New Haven, CT, USA.
| | - Richard J Zeifman
- NYU Langone Center for Psychedelic Medicine, NYU Grossman School of Medicine, New York, NY, USA
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Jeffrey Guss
- Department of Psychiatry, NYU Grossman School of Medicine, New York, NY, USA
| | - Robert Krause
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Yale School of Nursing, New Haven, CT, USA
- Centered PLLC, New Haven, CT, USA
| | - Hamideh Safi-Aghdam
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Surbhi Pathania
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
| | - Brian Pittman
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
| | - Deepak Cyril D'Souza
- Department of Psychiatry, Yale University School of Medicine, New Haven, CT, USA
- Psychiatry Service, VA Connecticut Healthcare System, West Haven, CT, USA
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Hervig MES, Zühlsdorff K, Olesen SF, Phillips B, Božič T, Dalley JW, Cardinal RN, Alsiö J, Robbins TW. 5-HT 2A and 5-HT 2C receptor antagonism differentially modulate reinforcement learning and cognitive flexibility: behavioural and computational evidence. Psychopharmacology (Berl) 2024:10.1007/s00213-024-06586-w. [PMID: 38594515 DOI: 10.1007/s00213-024-06586-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2023] [Accepted: 03/29/2024] [Indexed: 04/11/2024]
Abstract
RATIONALE Cognitive flexibility, the ability to adapt behaviour in response to a changing environment, is disrupted in several neuropsychiatric disorders, including obsessive-compulsive disorder and major depressive disorder. Evidence suggests that flexibility, which can be operationalised using reversal learning tasks, is modulated by serotonergic transmission. However, how exactly flexible behaviour and associated reinforcement learning (RL) processes are modulated by 5-HT action on specific receptors is unknown. OBJECTIVES We investigated the effects of 5-HT2A receptor (5-HT2AR) and 5-HT2C receptor (5-HT2CR) antagonism on flexibility and underlying RL mechanisms. METHODS Thirty-six male Lister hooded rats were trained on a touchscreen visual discrimination and reversal task. We evaluated the effects of systemic treatments with the 5-HT2AR and 5-HT2CR antagonists M100907 and SB-242084, respectively, on reversal learning and performance on probe trials where correct and incorrect stimuli were presented with a third, probabilistically rewarded, stimulus. Computational models were fitted to task choice data to extract RL parameters, including a novel model designed specifically for this task. RESULTS 5-HT2AR antagonism impaired reversal learning only after an initial perseverative phase, during a period of random choice and then new learning. 5-HT2CR antagonism, on the other hand, impaired learning from positive feedback. RL models further differentiated these effects. 5-HT2AR antagonism decreased punishment learning rate (i.e. negative feedback) at high and low doses. The low dose also decreased reinforcement sensitivity (beta) and increased stimulus and side stickiness (i.e., the tendency to repeat a choice regardless of outcome). 5-HT2CR antagonism also decreased beta, but reduced side stickiness. CONCLUSIONS These data indicate that 5-HT2A and 5-HT2CRs both modulate different aspects of flexibility, with 5-HT2ARs modulating learning from negative feedback as measured using RL parameters and 5-HT2CRs for learning from positive feedback assessed through conventional measures.
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Affiliation(s)
- Mona El-Sayed Hervig
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
- Department of Neuroscience, University of Copenhagen, Copenhagen, DK-2200, Denmark
| | - Katharina Zühlsdorff
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK.
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK.
- The Alan Turing Institute, British Library, London, NW1 2DVB, UK.
| | - Sarah F Olesen
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, W1T 4JG, UK
| | - Benjamin Phillips
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
| | - Tadej Božič
- UCL Sainsbury Wellcome Centre for Neural Circuits and Behaviour, London, W1T 4JG, UK
| | - Jeffrey W Dalley
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
- Department of Psychiatry, Herchel Smith Building, Cambridge, CB2 0SZ, UK
| | - Rudolf N Cardinal
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
- Department of Psychiatry, Herchel Smith Building, Cambridge, CB2 0SZ, UK
- Liaison Psychiatry Service, Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge Biomedical Campus, Box 190, Cambridge, CB2 0QQ, UK
| | - Johan Alsiö
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
- School of Physiology, Pharmacology & Neuroscience, University of Bristol, Bristol, BS8 1TD, UK
| | - Trevor W Robbins
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
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11
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Mortaheb S, Fort LD, Mason NL, Mallaroni P, Ramaekers JG, Demertzi A. Dynamic Functional Hyperconnectivity after Psilocybin Intake is Primarily Associated with Oceanic Boundlessness. Biol Psychiatry Cogn Neurosci Neuroimaging 2024:S2451-9022(24)00084-3. [PMID: 38588855 DOI: 10.1016/j.bpsc.2024.04.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Revised: 03/28/2024] [Accepted: 04/01/2024] [Indexed: 04/10/2024]
Abstract
BACKGROUND Psilocybin is a widely studied psychedelic substance, which leads to the psychedelic state, a specific altered state of consciousness. To date, the relationship between the psychedelic state's neurobiological and experiential patterns remains under-characterized as they are often analyzed separately. We investigated the relationship between neurobiological and experiential patterns after psilocybin by focusing on the link between dynamic cerebral connectivity and retrospective questionnaire assessment. METHODS Healthy participants were randomized to receive either psilocybin (n=22) or placebo (n=27) and scanned for six minutes in eyes open resting state during the peak subjective drug effect (102 minutes post-treatment) in ultra-high field 7T MRI. The 5D-ASC Rating Scale was administered 360 minutes after drug intake. RESULTS Under psilocybin, there were alterations across all dimensions of the 5D-ASC scale, and widespread increases in averaged brain functional connectivity. Further time-varying functional connectivity analysis unveiled a recurrent hyperconnected pattern characterized by low BOLD signal amplitude, suggesting heightened cortical arousal. In terms of neuro-experiential links, canonical correlation analysis showed higher transition probabilities to the hyperconnected pattern with feelings of oceanic boundlessness, and secondly with visionary restructuralization. CONCLUSIONS Psilocybin generates profound alterations both at the brain and at the experiential level. We suggest that the brain's tendency to enter a hyperconnected-hyperarousal pattern under psilocybin represents the potential to entertain variant mental associations. These findings illuminate the intricate interplay between brain dynamics and subjective experience under psilocybin, providing insights into the neurophysiology and neuro-experiential qualities of the psychedelic state.
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Affiliation(s)
- Sepehr Mortaheb
- Physiology of Cognition, GIGA-CRC In Vivo Imaging, University of Liège, Belgium; Fund for Scientific Research FNRS, Brussels, Belgium
| | - Larry D Fort
- Physiology of Cognition, GIGA-CRC In Vivo Imaging, University of Liège, Belgium; Fund for Scientific Research FNRS, Brussels, Belgium
| | - Natasha L Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, The Netherlands
| | - Pablo Mallaroni
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, The Netherlands
| | - Johannes G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, The Netherlands
| | - Athena Demertzi
- Physiology of Cognition, GIGA-CRC In Vivo Imaging, University of Liège, Belgium; Fund for Scientific Research FNRS, Brussels, Belgium; Psychology & Neuroscience of Cognition (PsyNCog), University of Liège, Belgium.
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12
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Tap SC. The potential of 5-methoxy-N,N-dimethyltryptamine in the treatment of alcohol use disorder: A first look at therapeutic mechanisms of action. Addict Biol 2024; 29:e13386. [PMID: 38600715 PMCID: PMC11007263 DOI: 10.1111/adb.13386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/24/2023] [Accepted: 02/13/2024] [Indexed: 04/12/2024]
Abstract
Alcohol use disorder (AUD) remains one of the most prevalent psychiatric disorders worldwide with high economic costs. Current treatment options show modest efficacy and relapse rates are high. Furthermore, there are increases in the treatment gap and few new medications have been approved in the past 20 years. Recently, psychedelic-assisted therapy with psilocybin and lysergic acid diethylamide has garnered significant attention in the treatment of AUD. Yet, they require significant amounts of therapist input due to prolonged subjective effects (~4-12 h) leading to high costs and impeding implementation. Accordingly, there is an increasing interest in the rapid and short-acting psychedelic 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT). This paper offers a first look at potential therapeutic mechanisms for AUD by reviewing the current literature on 5-MeO-DMT. Primarily, 5-MeO-DMT is able to induce mystical experiences and ego-dissolution together with increases in psychological flexibility and mindfulness. This could decrease AUD symptoms through the alleviation of psychiatric mood-related comorbidities consistent with the negative reinforcement and self-medication paradigms. In addition, preliminary evidence indicates that 5-MeO-DMT modulates neural oscillations that might subserve ego-dissolution (increases in gamma), psychological flexibility and mindfulness (increases in theta), and the reorganization of executive control networks (increases in coherence across frequencies) that could improve emotion regulation and inhibition. Finally, animal studies show that 5-MeO-DMT is characterized by neuroplasticity, anti-inflammation, 5-HT2A receptor agonism, and downregulation of metabotropic glutamate receptor 5 with clinical implications for AUD and psychiatric mood-related comorbidities. The paper concludes with several recommendations for future research to establish the purported therapeutic mechanisms of action.
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Affiliation(s)
- Stephan C. Tap
- Department of PsychiatryGroningen University Medical CenterGroningenThe Netherlands
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13
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Tolle HM, Farah JC, Mallaroni P, Mason NL, Ramaekers JG, Amico E. The unique neural signature of your trip: Functional connectome fingerprints of subjective psilocybin experience. Netw Neurosci 2024; 8:203-225. [PMID: 38562294 PMCID: PMC10898784 DOI: 10.1162/netn_a_00349] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Accepted: 10/23/2023] [Indexed: 04/04/2024] Open
Abstract
The emerging neuroscientific frontier of brain fingerprinting has recently established that human functional connectomes (FCs) exhibit fingerprint-like idiosyncratic features, which map onto heterogeneously distributed behavioral traits. Here, we harness brain-fingerprinting tools to extract FC features that predict subjective drug experience induced by the psychedelic psilocybin. Specifically, in neuroimaging data of healthy volunteers under the acute influence of psilocybin or a placebo, we show that, post psilocybin administration, FCs become more idiosyncratic owing to greater intersubject dissimilarity. Moreover, whereas in placebo subjects idiosyncratic features are primarily found in the frontoparietal network, in psilocybin subjects they concentrate in the default mode network (DMN). Crucially, isolating the latter revealed an FC pattern that predicts subjective psilocybin experience and is characterized by reduced within-DMN and DMN-limbic connectivity, as well as increased connectivity between the DMN and attentional systems. Overall, these results contribute to bridging the gap between psilocybin-mediated effects on brain and behavior, while demonstrating the value of a brain-fingerprinting approach to pharmacological neuroimaging.
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Affiliation(s)
- Hanna M. Tolle
- Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
| | - Juan Carlos Farah
- Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
- School of Engineering, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne, Switzerland
| | - Pablo Mallaroni
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Natasha L. Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Johannes G. Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, Netherlands
| | - Enrico Amico
- Neuro-X Institute, École Polytechnique Fédérale de Lausanne (EPFL), Geneva, Switzerland
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14
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Juliani A, Safron A, Kanai R. Deep CANALs: a deep learning approach to refining the canalization theory of psychopathology. Neurosci Conscious 2024; 2024:niae005. [PMID: 38533457 PMCID: PMC10965250 DOI: 10.1093/nc/niae005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 01/15/2024] [Accepted: 01/19/2024] [Indexed: 03/28/2024] Open
Abstract
Psychedelic therapy has seen a resurgence of interest in the last decade, with promising clinical outcomes for the treatment of a variety of psychopathologies. In response to this success, several theoretical models have been proposed to account for the positive therapeutic effects of psychedelics. One of the more prominent models is "RElaxed Beliefs Under pSychedelics," which proposes that psychedelics act therapeutically by relaxing the strength of maladaptive high-level beliefs encoded in the brain. The more recent "CANAL" model of psychopathology builds on the explanatory framework of RElaxed Beliefs Under pSychedelics by proposing that canalization (the development of overly rigid belief landscapes) may be a primary factor in psychopathology. Here, we make use of learning theory in deep neural networks to develop a series of refinements to the original CANAL model. Our primary theoretical contribution is to disambiguate two separate optimization landscapes underlying belief representation in the brain and describe the unique pathologies which can arise from the canalization of each. Along each dimension, we identify pathologies of either too much or too little canalization, implying that the construct of canalization does not have a simple linear correlation with the presentation of psychopathology. In this expanded paradigm, we demonstrate the ability to make novel predictions regarding what aspects of psychopathology may be amenable to psychedelic therapy, as well as what forms of psychedelic therapy may ultimately be most beneficial for a given individual.
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Affiliation(s)
- Arthur Juliani
- Microsoft Research , Microsoft, 300 Lafayette St, New York, NY 10012, USA
| | - Adam Safron
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, 600 N Wolfe St, Baltimore, MD 21205, USA
| | - Ryota Kanai
- Neurotechnology R & D Unit, Araya Inc, 6F Sanpo Sakuma Building, 1-11 Kandasakumacho, Chiyoda-ku, Tokyo 101-0025, Japan
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15
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Romero P, Czakó A, van den Brink W, Demetrovics Z. Psychedelic-assisted therapy for people with gambling disorder? J Behav Addict 2024; 13:6-11. [PMID: 38421388 PMCID: PMC10988418 DOI: 10.1556/2006.2024.00004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2023] [Revised: 12/16/2023] [Accepted: 01/12/2024] [Indexed: 03/02/2024] Open
Abstract
Gambling disorder is a severe mental health and behavioural problem with harmful consequences, including financial, relationship and mental health problems. The present paper initiates discussion on the use of psychedelics combined with psychotherapeutic support as a potential treatment option for people living with a gambling disorder. Recent studies have shown promising results using psychedelic-assisted therapy (PAT) to treat anxiety, depression, post-traumatic stress disorder, and various substance use disorders. Considering the similarities in the underlying psychosocial and neurobiological mechanisms of gambling disorder and other addictive disorders, the authors suggest that psychedelic-assisted therapy could be effective in treating gambling disorder. The paper also underscores the need for further research into the viability and effectiveness of psychedelic-assisted therapy for gambling disorder.
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Affiliation(s)
- Pedro Romero
- Centre of Excellence in Responsible Gaming, University of Gibraltar, Gibraltar, Gibraltar
| | - Andrea Czakó
- Centre of Excellence in Responsible Gaming, University of Gibraltar, Gibraltar, Gibraltar
- Institute of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary
| | - Wim van den Brink
- Amsterdam University Medical Centers, Department of Psychiatry, Amsterdam, The Netherlands
| | - Zsolt Demetrovics
- Centre of Excellence in Responsible Gaming, University of Gibraltar, Gibraltar, Gibraltar
- Institute of Psychology, ELTE Eötvös Loránd University, Budapest, Hungary
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16
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Ibanez A, Herzog R, Barbey F, Islam MN, Rueda-Delgado L, Nolan H, Prado P, Krylova M, Javaheripour N, Danyeli L, Sen Z, Walter M, Odonnell P, Buhl D, Murphy B, Izyurov I. High-order brain interactions in ketamine during rest and task: A double-blinded cross-over design using portable EEG. RESEARCH SQUARE 2024:rs.3.rs-3954073. [PMID: 38562802 PMCID: PMC10984031 DOI: 10.21203/rs.3.rs-3954073/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
In a double-blinded cross-over design, 30 adults (mean age = 25.57, SD = 3.74; all male) were administered racemic ketamine and compared against saline infusion as a control. Both task-driven (auditory oddball paradigm) and resting-state EEG were recorded. HOI were computed using advanced multivariate information theory tools, allowing us to quantify nonlinear statistical dependencies between all possible electrode combinations. Results: Ketamine increased redundancy in brain dynamics, most significantly in the alpha frequency band. Redundancy was more evident during the resting state, associated with a shift in conscious states towards more dissociative tendencies. Furthermore, in the task-driven context (auditory oddball), the impact of ketamine on redundancy was more significant for predictable (standard stimuli) compared to deviant ones. Finally, associations were observed between ketamine's HOI and experiences of derealization. Conclusions: Ketamine appears to increase redundancy and genuine HOI across metrics, suggesting these effects correlate with consciousness alterations towards dissociation. HOI represents an innovative method to combine all signal spatial interactions obtained from low-density dry EEG in drug interventions, as it is the only approach that exploits all possible combinations from different electrodes. This research emphasizes the potential of complexity measures coupled with portable EEG devices in monitoring shifts in consciousness, especially when paired with low-density configurations, paving the way for better understanding and monitoring of pharmacological-induced changes.
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17
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Jylkkä J. Naturalism and the hard problem of mysticism in psychedelic science. Front Psychol 2024; 15:1112103. [PMID: 38558777 PMCID: PMC10979935 DOI: 10.3389/fpsyg.2024.1112103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Accepted: 02/12/2024] [Indexed: 04/04/2024] Open
Abstract
Psychedelic substances are known to facilitate mystical-type experiences which can include metaphysical beliefs about the fundamental nature of reality. Such insights have been criticized as being incompatible with naturalism and therefore false. This leads to two problems. The easy problem is to elaborate on what is meant by the "fundamental nature of reality," and whether mystical-type conceptions of it are compatible with naturalism. The hard problem is to show how mystical-type insights, which from the naturalistic perspective are brain processes, could afford insight into the nature of reality beyond the brain. I argue that naturalism is less restrictive than commonly assumed, allowing that reality can be more than what science can convey. I propose that what the mystic refers to as the ultimate nature of reality can be considered as its representation- and observation-independent nature, and that mystical-type conceptions of it can be compatible with science. However, showing why the claims of the mystic would be true requires answering the hard problem. I argue that we can in fact directly know the fundamental nature of one specific part of reality, namely our own consciousness. Psychedelics may amplify our awareness of what consciousness is in itself, beyond our conceptual models about it. Moreover, psychedelics may aid us to become aware of the limits of our models of reality. However, it is far from clear how mystical-type experience could afford access to the fundamental nature of reality at large, beyond one's individual consciousness. I conclude that mystical-type conceptions about reality may be compatible with naturalism, but not verifiable.
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Affiliation(s)
- Jussi Jylkkä
- Department of Psychology, Åbo Akademi University, Turku, Finland
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18
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Marrocu A, Kettner H, Weiss B, Zeifman RJ, Erritzoe D, Carhart-Harris RL. Psychiatric risks for worsened mental health after psychedelic use. J Psychopharmacol 2024; 38:225-235. [PMID: 38491857 PMCID: PMC10944581 DOI: 10.1177/02698811241232548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/18/2024]
Abstract
BACKGROUND Resurgent psychedelic research has largely supported the safety and efficacy of psychedelic therapy for the treatment of various psychiatric disorders. As psychedelic use and therapy increase in prevalence, so does the importance of understanding associated risks. Cases of prolonged negative psychological responses to psychedelic therapy seem to be rare; however, studies are limited by biases and small sample sizes. The current analytical approach was motivated by the question of whether rare but significant adverse effects have been under-sampled in psychedelic research studies. METHODS A "bottom margin analysis" approach was taken to focus on negative responders to psychedelic use in a pool of naturalistic, observational prospective studies (N = 807). We define "negative response" by a clinically meaningful decline in a generic index of mental health, that is, one standard error from the mean decrease in psychological well-being 4 weeks post-psychedelic use (vs pre-use baseline). We then assessed whether a history of diagnosed mental illness can predict negative responses. RESULTS We find that 16% of the cohort falls into the "negative responder" subset. Parsing the sample by self-reported history of psychiatric diagnoses, results revealed a disproportionate prevalence of negative responses among those reporting a prior personality disorder diagnosis (31%). One multivariate regression model indicated a greater than four-fold elevated risk of adverse psychological responses to psychedelics in the personality disorder subsample (b = 1.425, p < 0.05). CONCLUSION We infer that the presence of a personality disorder may represent an elevated risk for psychedelic use and hypothesize that the importance of psychological support and good therapeutic alliance may be increased in this population.
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Affiliation(s)
- Alessia Marrocu
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Hannes Kettner
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Brandon Weiss
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Richard J Zeifman
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- NYU Langone Center for Psychedelic Medicine, NYU Grossman School of Medicine, New York, NY, USA
| | - David Erritzoe
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - Robin L Carhart-Harris
- Centre for Psychedelic Research, Division of Psychiatry, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- Carhart-Harris Lab, Departments of Neurology and Psychiatry, University of California San Francisco, San Francisco, CA, USA
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Silverstein BH, Kolbman N, Nelson A, Liu T, Guzzo P, Gilligan J, Lee U, Mashour GA, Vanini G, Pal D. Psilocybin induces dose-dependent changes in functional network organization in rat cortex. bioRxiv 2024:2024.02.09.579718. [PMID: 38405722 PMCID: PMC10888735 DOI: 10.1101/2024.02.09.579718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/27/2024]
Abstract
Psilocybin produces an altered state of consciousness in humans and is associated with complex spatiotemporal changes in brain networks. Given the emphasis on rodent models for mechanistic studies, there is a need for characterization of the effect of psilocybin on brain-wide network dynamics. Previous rodent studies of psychedelics, using electroencephalogram, have primarily been done with sparse electrode arrays that offered limited spatial resolution precluding network level analysis, and have been restricted to lower gamma frequencies. Therefore, in the study, we used electroencephalographic recordings from 27 sites (electrodes) across rat cortex (n=6 male, 6 female) to characterize the effect of psilocybin (0.1 mg/kg, 1 mg/kg, and 10 mg/kg delivered over an hour) on network organization as inferred through changes in node degree (index of network density) and connection strength (weighted phase-lag index). The removal of aperiodic component from the electroencephalogram localized the primary oscillatory changes to theta (4-10 Hz), medium gamma (70-110 Hz), and high gamma (110-150 Hz) bands, which were used for the network analysis. Additionally, we determined the concurrent changes in theta-gamma phase-amplitude coupling. We report that psilocybin, in a dose-dependent manner, 1) disrupted theta-gamma coupling [p<0.05], 2) increased frontal high gamma connectivity [p<0.05] and posterior theta connectivity [p≤0.049], and 3) increased frontal high gamma [p<0.05] and posterior theta [p≤0.046] network density. The medium gamma frontoparietal connectivity showed a nonlinear relationship with psilocybin dose. Our results suggest that high-frequency network organization, decoupled from local theta-phase, may be an important signature of psilocybin-induced non-ordinary state of consciousness.
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Affiliation(s)
- Brian H Silverstein
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Center for Consciousness Science, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Nicholas Kolbman
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Center for Consciousness Science, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Amanda Nelson
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Tiecheng Liu
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Peter Guzzo
- Tryp Therapeutics, Kelowna, British Columbia, V1Y 7T2, Canada
| | - Jim Gilligan
- Tryp Therapeutics, Kelowna, British Columbia, V1Y 7T2, Canada
| | - UnCheol Lee
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Center for Consciousness Science, University of Michigan, Ann Arbor, Michigan 48109, USA
- Michigan Psychedelic Center, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - George A Mashour
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Center for Consciousness Science, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Pharmacology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Michigan Psychedelic Center, University of Michigan, Ann Arbor, Michigan 48109, USA
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Giancarlo Vanini
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Center for Consciousness Science, University of Michigan, Ann Arbor, Michigan 48109, USA
- Michigan Psychedelic Center, University of Michigan, Ann Arbor, Michigan 48109, USA
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Dinesh Pal
- Department of Anesthesiology, University of Michigan, Ann Arbor, Michigan 48109, USA
- Center for Consciousness Science, University of Michigan, Ann Arbor, Michigan 48109, USA
- Michigan Psychedelic Center, University of Michigan, Ann Arbor, Michigan 48109, USA
- Neuroscience Graduate Program, University of Michigan, Ann Arbor, Michigan 48109, USA
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, Michigan 48109, USA
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20
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Villiger D. Giving Consent to the Ineffable. NEUROETHICS-NETH 2024; 17:11. [PMID: 38371714 PMCID: PMC10869409 DOI: 10.1007/s12152-024-09545-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Accepted: 01/22/2024] [Indexed: 02/20/2024]
Abstract
A psychedelic renaissance is currently taking place in mental healthcare. The number of psychedelic-assisted therapy trials is growing steadily, and some countries already grant psychiatrists special permission to use psychedelics in non-research contexts under certain conditions. These clinical advances must be accompanied by ethical inquiry. One pressing ethical question involves whether patients can even give informed consent to psychedelic-assisted therapy: the treatment's transformative nature seems to block its assessment, suggesting that patients are unable to understand what undergoing psychedelic-assisted therapy actually means for them and whether it aligns with their values. The present paper argues that patients often have sufficient knowledge to give informed consent because they know that they want to change their negative status quo and that psychedelic-assisted therapy offers an effective way to do so. Accordingly, patients can understand what the transformative nature of psychedelic-assisted therapy means for them and a make a value-aligned choice even if they are unable to anticipate the manifestation of a psychedelic experience.
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Affiliation(s)
- Daniel Villiger
- Institute of Philosophy, University of Zurich, Zollikerstrasse 117, 8008 Zurich, Switzerland
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21
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Acevedo EC, Uhler S, White KP, Al-Shawaf L. What Predicts Beneficial Outcomes in Psychedelic Use? A Quantitative Content Analysis of Psychedelic Health Outcomes. J Psychoactive Drugs 2024:1-10. [PMID: 38341606 DOI: 10.1080/02791072.2024.2314729] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 12/19/2023] [Indexed: 02/12/2024]
Abstract
Interest in psychedelics and their possible therapeutic potential has been growing. Metaphysical belief theory asserts that these benefits stem from the adoption of comforting supernatural beliefs following a mystical experience. By contrast, predictive self-binding theory suggests that the beneficial outcomes of psychedelics are primarily driven by psychological insights. The present study tests these competing models of psychedelic benefits. We conducted a quantitative content analysis on unsolicited self-reports of psychedelic users available on Erowid.org, to examine the potential relations between psychological insight, ego dissolution, therapeutic intent, altered metaphysical belief, and enduring health outcomes. We randomly selected, coded, and analyzed two hundred forty psychedelic experience reports from the website. Path analysis using structural equation modeling showed that psychological insight, not metaphysical beliefs, uniquely predicted beneficial outcomes. Moreover, beneficial outcomes' positive relation to ego dissolution and therapeutic intent was fully mediated by psychological insight. These findings support the predictive self-binding model over the metaphysical belief model.
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Affiliation(s)
- Elias C Acevedo
- Department of Psychology, University of Colorado, Colorado Springs, CO, USA
| | - Scott Uhler
- Department of Psychology, University of Colorado, Colorado Springs, CO, USA
| | - Kaitlyn P White
- Department of Psychology, University of Colorado, Colorado Springs, CO, USA
| | - Laith Al-Shawaf
- Department of Psychology, University of Colorado, Colorado Springs, CO, USA
- Lyda Hill Institute for Human Resilience, University of Colorado, Colorado Springs, USA
- Institute for Advanced Study, Toulouse, France
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22
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Timmermann C, Zeifman RJ, Erritzoe D, Nutt DJ, Carhart-Harris RL. Effects of DMT on mental health outcomes in healthy volunteers. Sci Rep 2024; 14:3097. [PMID: 38326357 PMCID: PMC10850177 DOI: 10.1038/s41598-024-53363-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 01/30/2024] [Indexed: 02/09/2024] Open
Abstract
Psilocybin, a serotonergic psychedelic, is being increasingly researched in clinical studies for the treatment of psychiatric disorders. The relatively lengthy duration of oral psilocybin's acute effects (4-6 h) may have pragmatic and cost-effectiveness limitations. Here, we explored the effects of intravenous (IV) N,N-Dimethyltryptamine (DMT), a closely related, but faster-acting psychedelic intervention, on mental health outcomes in healthy volunteers. Data is reported from two separate analyses: (1) A comparison of mental health-related variables 1 week after 7, 14, 18, and 20 mg of IV DMT versus IV saline placebo (n = 13) and, (2) A prospective dataset assessing effects before versus 2 weeks after 20 mg of IV DMT (n = 17). Mental health outcomes included measures of depression severity (QIDS-SR16), trait anxiety (STAI-T), Neuroticism (NEO-FFI), wellbeing (WHO-5), meaning in life (MLQ), optimism (LOT-R), and gratitude (GQ-6). In both the prospective and placebo-controlled datasets, significant improvements in scores of depression were found 1-2 weeks after DMT administration. Significant reductions in trait Neuroticism were only found for the placebo-controlled sample. Finally, changes in depression and trait anxiety correlated with acute peak experiences (assessed via 'Oceanic Boundlessness'). While the use of two separate cohorts in pooled analysis limits the generalizability of these correlational findings, these results suggest that DMT may reduce depressive symptomatology by inducing peak experiences. The short half-life of IV DMT and its potential for flexible dosing via controlled infusions makes it an appealing candidate for psychedelic medicine. Further research in clinical samples is needed to corroborate the therapeutic potential of DMT.
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Affiliation(s)
- Christopher Timmermann
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK.
| | - Richard J Zeifman
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- NYU Langone Center for Psychedelic Medicine, NYU Grosssman School of Medicine, New York, USA
| | - David Erritzoe
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
| | - David J Nutt
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- Centre for Psychiatry, Division of Brain Sciences, Faculty of Medicine, Imperial College, London, UK
| | - Robin L Carhart-Harris
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, UK
- Psychedelics Division, Neuroscape, Department of Neurology, University of California, San Francisco, USA
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23
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Šabanović M, Lazari A, Blanco-Pozo M, Tisca C, Tachrount M, Martins-Bach AB, Lerch JP, Walton ME, Bannerman DM. Lasting dynamic effects of the psychedelic 2,5-dimethoxy-4-iodoamphetamine ((±)-DOI) on cognitive flexibility. Mol Psychiatry 2024:10.1038/s41380-024-02439-2. [PMID: 38321122 DOI: 10.1038/s41380-024-02439-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 02/08/2024]
Abstract
Psychedelic drugs can aid fast and lasting remission from various neuropsychiatric disorders, though the underlying mechanisms remain unclear. Preclinical studies suggest serotonergic psychedelics enhance neuronal plasticity, but whether neuroplastic changes can also be seen at cognitive and behavioural levels is unexplored. Here we show that a single dose of the psychedelic 2,5-dimethoxy-4-iodoamphetamine ((±)-DOI) affects structural brain plasticity and cognitive flexibility in young adult mice beyond the acute drug experience. Using ex vivo magnetic resonance imaging, we show increased volumes of several sensory and association areas one day after systemic administration of 2 mgkg-1 (±)-DOI. We then demonstrate lasting effects of (±)-DOI on cognitive flexibility in a two-step probabilistic reversal learning task where 2 mgkg-1 (±)-DOI improved the rate of adaptation to a novel reversal in task structure occurring one-week post-treatment. Strikingly, (±)-DOI-treated mice started learning from reward omissions, a unique strategy not typically seen in mice in this task, suggesting heightened sensitivity to previously overlooked cues. Crucially, further experiments revealed that (±)-DOI's effects on cognitive flexibility were contingent on the timing between drug treatment and the novel reversal, as well as on the nature of the intervening experience. (±)-DOI's facilitation of both cognitive adaptation and novel thinking strategies may contribute to the clinical benefits of psychedelic-assisted therapy, particularly in cases of perseverative behaviours and a resistance to change seen in depression, anxiety, or addiction. Furthermore, our findings highlight the crucial role of time-dependent neuroplasticity and the influence of experiential factors in shaping the therapeutic potential of psychedelic interventions for impaired cognitive flexibility.
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Affiliation(s)
- Merima Šabanović
- Department of Experimental Psychology, University of Oxford, OX1 3SR, Oxford, UK.
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, 10065, USA.
| | - Alberto Lazari
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK
| | - Marta Blanco-Pozo
- Department of Experimental Psychology, University of Oxford, OX1 3SR, Oxford, UK
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK
- Department of Biology, Stanford University, Stanford, CA, 94305, USA
| | - Cristiana Tisca
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK
| | - Mohamed Tachrount
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK
| | - Aurea B Martins-Bach
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK
| | - Jason P Lerch
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK
| | - Mark E Walton
- Department of Experimental Psychology, University of Oxford, OX1 3SR, Oxford, UK.
- Wellcome Centre for Integrative Neuroimaging, University of Oxford, OX3 9DU, Oxford, UK.
| | - David M Bannerman
- Department of Experimental Psychology, University of Oxford, OX1 3SR, Oxford, UK.
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24
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Barba T, Kettner H, Radu C, Peill JM, Roseman L, Nutt DJ, Erritzoe D, Carhart-Harris R, Giribaldi B. Psychedelics and sexual functioning: a mixed-methods study. Sci Rep 2024; 14:2181. [PMID: 38326446 PMCID: PMC10850066 DOI: 10.1038/s41598-023-49817-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 12/12/2023] [Indexed: 02/09/2024] Open
Abstract
Do psychedelics affect sexual functioning postacutely? Anecdotal and qualitative evidence suggests they do, but this has never been formally tested. While sexual functioning and satisfaction are generally regarded as an important aspect of human wellbeing, sexual dysfunction is a common symptom of mental health disorders. It is also a common side effect of selective serotonin reuptake inhibitors (SSRIs), a first line treatment for depression. The aim of the present paper was to investigate the post-acute effects of psychedelics on self-reported sexual functioning, combining data from two independent studies, one large and naturalistic and the other a smaller but controlled clinical trial. Naturalistic use of psychedelics was associated with improvements in several facets of sexual functioning and satisfaction, including improved pleasure and communication during sex, satisfaction with one's partner and physical appearance. Convergent results were found in a controlled trial of psilocybin therapy versus an SSRI, escitalopram, for depression. In this trial, patients treated with psilocybin reported positive changes in sexual functioning after treatment, while patients treated with escitalopram did not. Despite focusing on different populations and settings, this is the first research study to quantitively investigate the effects of psychedelics on sexual functioning. Results imply a potential positive effect on post-acute sexual functioning and highlight the need for more research on this.
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Affiliation(s)
- Tommaso Barba
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, UK.
| | - Hannes Kettner
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, UK
- Psychedelics Division, Neuroscape, Department of Neurology, University of California San Francisco, San Francisco, United States
| | - Caterina Radu
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Joseph M Peill
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Leor Roseman
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, UK
| | - David J Nutt
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, UK
| | - David Erritzoe
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, UK
| | - Robin Carhart-Harris
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, UK
- Psychedelics Division, Neuroscape, Department of Neurology, University of California San Francisco, San Francisco, United States
| | - Bruna Giribaldi
- Department of Medicine, Centre for Psychedelic Research, Imperial College London, London, UK
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25
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Mediano PAM, Rosas FE, Timmermann C, Roseman L, Nutt DJ, Feilding A, Kaelen M, Kringelbach ML, Barrett AB, Seth AK, Muthukumaraswamy S, Bor D, Carhart-Harris RL. Effects of External Stimulation on Psychedelic State Neurodynamics. ACS Chem Neurosci 2024; 15:462-471. [PMID: 38214686 PMCID: PMC10853937 DOI: 10.1021/acschemneuro.3c00289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 09/26/2023] [Indexed: 01/13/2024] Open
Abstract
Recent findings have shown that psychedelics reliably enhance brain entropy (understood as neural signal diversity), and this effect has been associated with both acute and long-term psychological outcomes, such as personality changes. These findings are particularly intriguing, given that a decrease of brain entropy is a robust indicator of loss of consciousness (e.g., from wakefulness to sleep). However, little is known about how context impacts the entropy-enhancing effect of psychedelics, which carries important implications for how it can be exploited in, for example, psychedelic psychotherapy. This article investigates how brain entropy is modulated by stimulus manipulation during a psychedelic experience by studying participants under the effects of lysergic acid diethylamide (LSD) or placebo, either with gross state changes (eyes closed vs open) or different stimuli (no stimulus vs music vs video). Results show that while brain entropy increases with LSD under all of the experimental conditions, it exhibits the largest changes when subjects have their eyes closed. Furthermore, brain entropy changes are consistently associated with subjective ratings of the psychedelic experience, but this relationship is disrupted when participants are viewing a video─potentially due to a "competition" between external stimuli and endogenous LSD-induced imagery. Taken together, our findings provide strong quantitative evidence of the role of context in modulating neural dynamics during a psychedelic experience, underlining the importance of performing psychedelic psychotherapy in a suitable environment.
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Affiliation(s)
- Pedro A. M. Mediano
- Department
of Computing, Imperial College London, London SW7 2AZ, U.K.
- Department
of Psychology, University of Cambridge, Cambridge CB2 3EB, U.K.
| | - Fernando E. Rosas
- Department
of Informatics, University of Sussex, Brighton BN1 9RH, U.K.
- Centre
for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, U.K.
- Centre
for Complexity Science, Imperial College
London, London SW7 2AZ, U.K.
- Centre for
Eudaimonia and Human Flourishing, University
of Oxford, Oxford OX1 2JD, U.K.
| | - Christopher Timmermann
- Centre
for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, U.K.
| | - Leor Roseman
- Centre
for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, U.K.
| | - David J. Nutt
- Centre
for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, U.K.
| | | | | | - Morten L. Kringelbach
- Centre for
Eudaimonia and Human Flourishing, University
of Oxford, Oxford OX1 2JD, U.K.
- Department
of Psychiatry, University of Oxford, Oxford OX1 2JD, U.K.
- Center
for Music in the Brain, Department of Clinical Medicine, Aarhus University, Aarhus 8000, Denmark
| | - Adam B. Barrett
- Sussex
Center for Consciousness Science and Department of Informatics, University of Sussex, Brighton BN1 9RH, U.K.
| | - Anil K. Seth
- Sussex
Center for Consciousness Science and Department of Informatics, University of Sussex, Brighton BN1 9RH, U.K.
- CIFAR Program on Brain, Mind, and Consciousness, Toronto M5G 1M1, Canada
| | - Suresh Muthukumaraswamy
- School
of Pharmacy, Faculty of Medical and Health Sciences, The University of Auckland, Auckland 1023, New Zealand
| | - Daniel Bor
- Department
of Psychology, University of Cambridge, Cambridge CB2 3EB, U.K.
- Department
of Psychology, Queen Mary University of
London, London E1 4NS, U.K.
| | - Robin L. Carhart-Harris
- Centre
for Psychedelic Research, Department of Brain Sciences, Imperial College London, London SW7 2AZ, U.K.
- Psychedelics
Division, Neuroscape, University of California
San Francisco, San Francisco, California 94117-1080, United States
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26
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Petranker R, Anderson T, Fewster EC, Aberman Y, Hazan M, Gaffrey M, Seli P. Keeping the promise: a critique of the current state of microdosing research. Front Psychiatry 2024; 15:1217102. [PMID: 38374976 PMCID: PMC10875010 DOI: 10.3389/fpsyt.2024.1217102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Accepted: 01/05/2024] [Indexed: 02/21/2024] Open
Abstract
Introduction The practice of taking small, sub-hallucinogenic doses of psychedelics, known as microdosing, has exploded in popularity over the last decade. Users claim benefits ranging from improved mood and enhanced creativity to an increased sense of meaning and connectedness in life. While research on microdosing is still lagging behind the shift in public opinion, several papers have been published in the last five years which attempted to assess the effects of microdosing. Methods This review paper aimed to critically analyze the research practices used in the recent wave of microdosing research: We reviewed 15 papers published before the closing date of this review in March 2022. Results Our review concludes that it is premature to draw any conclusions about the efficacy or safety of microdosing since the research quality cannot be considered confirmatory. Discussion We propose some potential causes for the current state of the literature and some suggestions for how these causes may be ameliorated.
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Affiliation(s)
- Rotem Petranker
- Department of Psychology, Neuroscience and Behaviour, Hamilton, ON, Canada
| | - Thomas Anderson
- Department of Psychology, University of Toronto, Toronto, ON, Canada
| | | | | | - Marik Hazan
- Independent Researcher, New York, NY, United States
| | - Michael Gaffrey
- Department of Psychology and Neuroscience, Duke University, Durham, NC, United States
| | - Paul Seli
- Department of Psychology and Neuroscience, Duke University, Durham, NC, United States
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27
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Murphy RJ, Godfrey K, Shaw AD, Muthukumaraswamy S, Sumner RL. Modulation of long-term potentiation following microdoses of LSD captured by thalamo-cortical modelling in a randomised, controlled trial. BMC Neurosci 2024; 25:7. [PMID: 38317077 PMCID: PMC10845757 DOI: 10.1186/s12868-024-00844-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 01/10/2024] [Indexed: 02/07/2024] Open
Abstract
BACKGROUND Microdosing psychedelics is a phenomenon with claimed cognitive benefits that are relatively untested clinically. Pre-clinically, psychedelics have demonstrated enhancing effects on neuroplasticity, which cannot be measured directly in humans, but may be indexed by non-invasive electroencephalography (EEG) paradigms. This study used a visual long-term potentiation (LTP) EEG paradigm to test the effects of microdosed lysergic acid diethylamide (LSD) on neural plasticity, both acutely while on the drug and cumulatively after microdosing every third day for six weeks. Healthy adult males (n = 80) completed the visual LTP paradigm at baseline, 2.5 h following a dose of 10 µg of LSD or inactive placebo, and 6 weeks later after taking 14 repeated microdoses. Visually induced LTP was used as indirect index of neural plasticity. Surface level event-related potential (ERPs) based analyses are presented alongside dynamic causal modelling of the source localised data using a generative thalamocortical model (TCM) of visual cortex to elucidate underlying synaptic circuitry. RESULTS Event-related potential (ERP) analyses of N1b and P2 components did not show evidence of changes in visually induced LTP by LSD either acutely or after 6 weeks of regular dosing. However modelling the complete timecourse of the ERP with the TCM demonstrated changes in laminar connectivity in primary visual cortex. This primarily included changes to self-gain and inhibitory input parameters acutely. Layer 2/3 to layer 5 excitatory connectivity was also different between LSD and placebo groups. After regular dosing only excitatory input from layer 2/3 into layer 5 and inhibitory input into layer 4 were different between groups. CONCLUSIONS Without modulation of the ERPs it is difficult to relate the findings to other studies visually inducing LTP. It also indicates the classic peak analysis may not be sensitive enough to demonstrate evidence for changes in LTP plasticity in humans at such low doses. The TCM provides a more sensitive approach to assessing changes to plasticity as differences in plasticity mediated laminar connectivity were found between the LSD and placebo groups. TRIAL REGISTRATION ANZCTR registration number ACTRN12621000436875; Registered 16/04/2021 https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=381476 .
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Affiliation(s)
- Robin J Murphy
- School of Pharmacy, University of Auckland, Auckland, New Zealand.
| | - Kate Godfrey
- Centre for Psychedelic Research, Department of Psychiatry, Imperial College London, London, UK
| | | | | | - Rachael L Sumner
- School of Pharmacy, University of Auckland, Auckland, New Zealand
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28
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Rogers SA, Heller EA, Corder G. Psilocybin-enhanced fear extinction linked to bidirectional modulation of cortical ensembles. bioRxiv 2024:2024.02.04.578811. [PMID: 38352491 PMCID: PMC10862786 DOI: 10.1101/2024.02.04.578811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/24/2024]
Abstract
The serotonin 2 receptor (5HT2R) agonist psilocybin has demonstrated rapid and long-lasting efficacy across neuropsychiatric disorders characterized by cognitive inflexibility. Psilocybin may accomplish this by inducing rapid and stable dendritic plasticity. However, the impact of psilocybin on patterns of neural activity underlying sustained changes in cognitive and behavioral flexibility has not been characterized. To test the hypothesis that psilocybin enhances behavioral flexibility by rapidly and persistently altering activity in cortical neural ensembles, we performed longitudinal single-cell calcium imaging in the retrosplenial cortex across a five-day trace fear learning and extinction assay. Leveraging tensor component analysis to identify neurons that modulate activity on multiple temporal scales, we found that a single-dose of psilocybin induced cortical ensemble turnover between fear learning and extinction days while oppositely modulating activity in fear- and extinction-active neurons. The extent of suppression of fear-active neurons and recruitment of extinction-active neurons were both predictive of psilocybin-enhanced fear extinction. These results both align with hypotheses that psilocybin enhances behavioral flexibility by recruiting new populations of neurons and introduce a new mechanism involving the suppression of fear-active populations in the retrosplenial cortex.
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Affiliation(s)
- Sophie A Rogers
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104
| | - Elizabeth A Heller
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104
| | - Gregory Corder
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104
- Department of Neuroscience, Mahoney Institute for Neurosciences, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104
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29
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De Filippo R, Schmitz D. Synthetic surprise as the foundation of the psychedelic experience. Neurosci Biobehav Rev 2024; 157:105538. [PMID: 38220035 PMCID: PMC10839673 DOI: 10.1016/j.neubiorev.2024.105538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2023] [Revised: 01/03/2024] [Accepted: 01/05/2024] [Indexed: 01/16/2024]
Abstract
Psychedelic agents, such as LSD and psilocybin, induce marked alterations in consciousness via activation of the 5-HT2A receptor (5-HT2ARs). We hypothesize that psychedelics enforce a state of synthetic surprise through the biased activation of the 5-HTRs system. This idea is informed by recent insights into the role of 5-HT in signaling surprise. The effects on consciousness, explained by the cognitive penetrability of perception, can be described within the predictive coding framework where surprise corresponds to prediction error, the mismatch between predictions and actual sensory input. Crucially, the precision afforded to the prediction error determines its effect on priors, enabling a dynamic interaction between top-down expectations and incoming sensory data. By integrating recent findings on predictive coding circuitry and 5-HT2ARs transcriptomic data, we propose a biological implementation with emphasis on the role of inhibitory interneurons. Implications arise for the clinical use of psychedelics, which may rely primarily on their inherent capacity to induce surprise in order to disrupt maladaptive patterns.
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Affiliation(s)
- Roberto De Filippo
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany.
| | - Dietmar Schmitz
- Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Neuroscience Research Center, 10117 Berlin, Germany; German Center for Neurodegenerative Diseases (DZNE) Berlin, 10117 Berlin, Germany; Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, Einstein Center for Neuroscience, 10117 Berlin, Germany; Charité-Universitätsmedizin Berlin, corporate member of Freie Universität Berlin, Humboldt-Universität Berlin, and Berlin Institute of Health, NeuroCure Cluster of Excellence, 10117 Berlin, Germany; Humboldt-Universität zu Berlin, Bernstein Center for Computational Neuroscience, Philippstr. 13, 10115 Berlin, Germany
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30
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Agin-Liebes G, Nielson EM, Zingman M, Kim K, Haas A, Owens LT, Rogers U, Bogenschutz M. Reports of self-compassion and affect regulation in psilocybin-assisted therapy for alcohol use disorder: An interpretive phenomenological analysis. Psychol Addict Behav 2024; 38:101-113. [PMID: 37276086 PMCID: PMC10696130 DOI: 10.1037/adb0000935] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
OBJECTIVE The primary aim of this qualitative study was to delineate psychological mechanisms of change in the first randomized controlled trial of psilocybin-assisted psychotherapy to treat alcohol use disorder (AUD). Theories regarding psychological processes involved in psychedelic therapy remain underdeveloped. METHOD Participants (N = 13) mostly identified as non-Hispanic and White, with approximately equal proportions of cisgender men and women. Participants engaged in semistructured interviews about their subjective experiences in the study. Questions probed the nature of participants' drinking before and after the study as well as coping patterns in response to strong emotions, stress, and cravings for alcohol. Verbatim transcripts were coded using Dedoose software, and content was analyzed with interpretive phenomenological analysis. RESULTS Participants reported that the psilocybin treatment helped them process emotions related to painful past events and helped promote states of self-compassion, self-awareness, and feelings of interconnectedness. The acute states during the psilocybin sessions were described as laying the foundation for developing more self-compassionate regulation of negative affect. Participants also described newfound feelings of belonging and an improved quality of relationships following the treatment. CONCLUSION Our results support the assertion that psilocybin increases the malleability of self-related processing, and diminishes shame-based and self-critical thought patterns while improving affect regulation and reducing alcohol cravings. These findings suggest that psychosocial treatments that integrate self-compassion training with psychedelic therapy may serve as a useful tool for enhancing psychological outcomes in the treatment of AUD. (PsycInfo Database Record (c) 2024 APA, all rights reserved).
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Affiliation(s)
- Gabrielle Agin-Liebes
- University of California, San Francisco, Department of Psychiatry, San Francisco CA, USA
- Neuroscape, Sandler Neurosciences Center, University of California, San Francisco, San Francisco CA, USA
| | | | - Michael Zingman
- NYU Langone Center for Psychedelic Medicine, Department of Psychiatry, NYU Grossman School of Medicine, New York, New York, USA
| | - Katherine Kim
- NYU Langone Center for Psychedelic Medicine, Department of Psychiatry, NYU Grossman School of Medicine, New York, New York, USA
| | - Alexandra Haas
- University of California, San Francisco, Department of Psychiatry, San Francisco CA, USA
| | - Lindsey T. Owens
- NYU Langone Center for Psychedelic Medicine, Department of Psychiatry, NYU Grossman School of Medicine, New York, New York, USA
- Department of Psychology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Ursula Rogers
- NYU Langone Center for Psychedelic Medicine, Department of Psychiatry, NYU Grossman School of Medicine, New York, New York, USA
| | - Michael Bogenschutz
- NYU Langone Center for Psychedelic Medicine, Department of Psychiatry, NYU Grossman School of Medicine, New York, New York, USA
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31
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Luo Q, Kanen JW, Bari A, Skandali N, Langley C, Knudsen GM, Alsiö J, Phillips BU, Sahakian BJ, Cardinal RN, Robbins TW. Comparable roles for serotonin in rats and humans for computations underlying flexible decision-making. Neuropsychopharmacology 2024; 49:600-608. [PMID: 37914893 PMCID: PMC10789782 DOI: 10.1038/s41386-023-01762-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 09/22/2023] [Accepted: 10/17/2023] [Indexed: 11/03/2023]
Abstract
Serotonin is critical for adapting behavior flexibly to meet changing environmental demands. Cognitive flexibility is important for successful attainment of goals, as well as for social interactions, and is frequently impaired in neuropsychiatric disorders, including obsessive-compulsive disorder. However, a unifying mechanistic framework accounting for the role of serotonin in behavioral flexibility has remained elusive. Here, we demonstrate common effects of manipulating serotonin function across two species (rats and humans) on latent processes supporting choice behavior during probabilistic reversal learning, using computational modelling. The findings support a role of serotonin in behavioral flexibility and plasticity, indicated, respectively, by increases or decreases in choice repetition ('stickiness') or reinforcement learning rates following manipulations intended to increase or decrease serotonin function. More specifically, the rate at which expected value increased following reward and decreased following punishment (reward and punishment 'learning rates') was greatest after sub-chronic administration of the selective serotonin reuptake inhibitor (SSRI) citalopram (5 mg/kg for 7 days followed by 10 mg/kg twice a day for 5 days) in rats. Conversely, humans given a single dose of an SSRI (20 mg escitalopram), which can decrease post-synaptic serotonin signalling, and rats that received the neurotoxin 5,7-dihydroxytryptamine (5,7-DHT), which destroys forebrain serotonergic neurons, exhibited decreased reward learning rates. A basic perseverative tendency ('stickiness'), or choice repetition irrespective of the outcome produced, was likewise increased in rats after the 12-day SSRI regimen and decreased after single dose SSRI in humans and 5,7-DHT in rats. These common effects of serotonergic manipulations on rats and humans-identified via computational modelling-suggest an evolutionarily conserved role for serotonin in plasticity and behavioral flexibility and have clinical relevance transdiagnostically for neuropsychiatric disorders.
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Affiliation(s)
- Qiang Luo
- National Clinical Research Center for Aging and Medicine at Huashan Hospital, State Key Laboratory of Medical Neurobiology and Ministry of Education Frontiers Center for Brain Science, Institutes of Brain Science and Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, 200433, P. R. China.
- Center for Computational Psychiatry, Ministry of Education Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence, Human Phenome Institute, Fudan University, Shanghai, 200433, China.
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK.
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK.
| | - Jonathan W Kanen
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
| | | | - Nikolina Skandali
- Department of Psychiatry, University of Cambridge, Cambridge, CB2 0SZ, UK
- Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, CB21 5EF, UK
- NIHR Cambridge Biomedical Research Centre, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - Christelle Langley
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
- Department of Psychiatry, University of Cambridge, Cambridge, CB2 0SZ, UK
| | - Gitte Moos Knudsen
- Neurobiology Research Unit, the Neuroscience Centre, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
- Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark
| | - Johan Alsiö
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
| | - Benjamin U Phillips
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
| | - Barbara J Sahakian
- National Clinical Research Center for Aging and Medicine at Huashan Hospital, State Key Laboratory of Medical Neurobiology and Ministry of Education Frontiers Center for Brain Science, Institutes of Brain Science and Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, 200433, P. R. China
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK
- Department of Psychiatry, University of Cambridge, Cambridge, CB2 0SZ, UK
| | - Rudolf N Cardinal
- Department of Psychiatry, University of Cambridge, Cambridge, CB2 0SZ, UK
- Cambridgeshire and Peterborough NHS Foundation Trust, Cambridge, CB21 5EF, UK
| | - Trevor W Robbins
- National Clinical Research Center for Aging and Medicine at Huashan Hospital, State Key Laboratory of Medical Neurobiology and Ministry of Education Frontiers Center for Brain Science, Institutes of Brain Science and Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai, 200433, P. R. China.
- Department of Psychology, University of Cambridge, Cambridge, CB2 3EB, UK.
- Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge, CB2 3EB, UK.
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Murray CH, Frohlich J, Haggarty CJ, Tare I, Lee R, de Wit H. Neural complexity is increased after low doses of LSD, but not moderate to high doses of oral THC or methamphetamine. Neuropsychopharmacology 2024:10.1038/s41386-024-01809-2. [PMID: 38287172 DOI: 10.1038/s41386-024-01809-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 01/07/2024] [Accepted: 01/17/2024] [Indexed: 01/31/2024]
Abstract
Neural complexity correlates with one's level of consciousness. During coma, anesthesia, and sleep, complexity is reduced. During altered states, including after lysergic acid diethylamide (LSD), complexity is increased. In the present analysis, we examined whether low doses of LSD (13 and 26 µg) were sufficient to increase neural complexity in the absence of altered states of consciousness. In addition, neural complexity was assessed after doses of two other drugs that significantly altered consciousness and mood: delta-9-tetrahydrocannabinol (THC; 7.5 and 15 mg) and methamphetamine (MA; 10 and 20 mg). In three separate studies (N = 73; 21, LSD; 23, THC; 29, MA), healthy volunteers received placebo or drug in a within-subjects design over three laboratory visits. During anticipated peak drug effects, resting state electroencephalography (EEG) recorded Limpel-Ziv complexity and spectral power. LSD, but not THC or MA, dose-dependently increased neural complexity. LSD also reduced delta and theta power. THC reduced, and MA increased, alpha power, primarily in frontal regions. Neural complexity was not associated with any subjective drug effect; however, LSD-induced reductions in delta and theta were associated with elation, and THC-induced reductions in alpha were associated with altered states. These data inform relationships between neural complexity, spectral power, and subjective states, demonstrating that increased neural complexity is not necessary or sufficient for altered states of consciousness. Future studies should address whether greater complexity after low doses of LSD is related to cognitive, behavioral, or therapeutic outcomes, and further examine the role of alpha desynchronization in mediating altered states of consciousness.
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Affiliation(s)
- Conor H Murray
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA.
- Department of Psychiatry and Biobehavioral Sciences, University of Los Angeles, California, 760 Westwood Plaza, Los Angeles, CA, 90024, USA.
| | - Joel Frohlich
- Institute for Neuromodulation and Neurotechnology, University of Tübingen, Otfried-Müller-Straße 45, 72076, Tübingen, Germany
- Institute for Advanced Consciousness Studies, Santa Monica, California; 2811 Wilshire Blvd # 510, Santa Monica, CA, 90403, USA
| | - Connor J Haggarty
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Ilaria Tare
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Royce Lee
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
| | - Harriet de Wit
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, 5841 S Maryland Ave, Chicago, IL, 60637, USA
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Kuhn RL. A landscape of consciousness: Toward a taxonomy of explanations and implications. Prog Biophys Mol Biol 2024:S0079-6107(23)00112-8. [PMID: 38281544 DOI: 10.1016/j.pbiomolbio.2023.12.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Revised: 09/12/2023] [Accepted: 12/25/2023] [Indexed: 01/30/2024]
Abstract
Diverse explanations or theories of consciousness are arrayed on a roughly physicalist-to-nonphysicalist landscape of essences and mechanisms. Categories: Materialism Theories (philosophical, neurobiological, electromagnetic field, computational and informational, homeostatic and affective, embodied and enactive, relational, representational, language, phylogenetic evolution); Non-Reductive Physicalism; Quantum Theories; Integrated Information Theory; Panpsychisms; Monisms; Dualisms; Idealisms; Paranormal and Altered States Theories; Challenge Theories. There are many subcategories, especially for Materialism Theories. Each explanation is self-described by its adherents, critique is minimal and only for clarification, and there is no attempt to adjudicate among the theories. The implications of consciousness categories of explanations or theories are assessed with respect to: meaning/purpose/value (if any); AI consciousness; virtual immortality; and survival beyond death. A landscape of consciousness, I suggest, offers perspective.
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Affiliation(s)
- Robert Lawrence Kuhn
- Closer To Truth (TV & Web), 1050 Park Avenue / Apt. 12B, New York, NY, 10028, USA.
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Ruffini G, Lopez-Sola E, Vohryzek J, Sanchez-Todo R. Neural Geometrodynamics, Complexity, and Plasticity: A Psychedelics Perspective. Entropy (Basel) 2024; 26:90. [PMID: 38275498 DOI: 10.3390/e26010090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 01/14/2024] [Accepted: 01/17/2024] [Indexed: 01/27/2024]
Abstract
We explore the intersection of neural dynamics and the effects of psychedelics in light of distinct timescales in a framework integrating concepts from dynamics, complexity, and plasticity. We call this framework neural geometrodynamics for its parallels with general relativity's description of the interplay of spacetime and matter. The geometry of trajectories within the dynamical landscape of "fast time" dynamics are shaped by the structure of a differential equation and its connectivity parameters, which themselves evolve over "slow time" driven by state-dependent and state-independent plasticity mechanisms. Finally, the adjustment of plasticity processes (metaplasticity) takes place in an "ultraslow" time scale. Psychedelics flatten the neural landscape, leading to heightened entropy and complexity of neural dynamics, as observed in neuroimaging and modeling studies linking increases in complexity with a disruption of functional integration. We highlight the relationship between criticality, the complexity of fast neural dynamics, and synaptic plasticity. Pathological, rigid, or "canalized" neural dynamics result in an ultrastable confined repertoire, allowing slower plastic changes to consolidate them further. However, under the influence of psychedelics, the destabilizing emergence of complex dynamics leads to a more fluid and adaptable neural state in a process that is amplified by the plasticity-enhancing effects of psychedelics. This shift manifests as an acute systemic increase of disorder and a possibly longer-lasting increase in complexity affecting both short-term dynamics and long-term plastic processes. Our framework offers a holistic perspective on the acute effects of these substances and their potential long-term impacts on neural structure and function.
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Affiliation(s)
- Giulio Ruffini
- Brain Modeling Department, Neuroelectrics, 08035 Barcelona, Spain
| | - Edmundo Lopez-Sola
- Brain Modeling Department, Neuroelectrics, 08035 Barcelona, Spain
- Computational Neuroscience Group, Universitat Pompeu Fabra, 08018 Barcelona, Spain
| | - Jakub Vohryzek
- Computational Neuroscience Group, Universitat Pompeu Fabra, 08018 Barcelona, Spain
- Centre for Eudaimonia and Human Flourishing, Linacre College, University of Oxford, Oxford OX3 9BX, UK
| | - Roser Sanchez-Todo
- Brain Modeling Department, Neuroelectrics, 08035 Barcelona, Spain
- Computational Neuroscience Group, Universitat Pompeu Fabra, 08018 Barcelona, Spain
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Kervadec E, Fauvel B, Strika-Bruneau L, Amirouche A, Verroust V, Piolino P, Romeo B, Benyamina A. Reduction of alcohol use and increase in psychological flexibility after a naturalistic psychedelic experience: a retrospective survey. Alcohol Alcohol 2024; 59:agad078. [PMID: 37981297 DOI: 10.1093/alcalc/agad078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Revised: 10/24/2023] [Accepted: 10/26/2023] [Indexed: 11/21/2023] Open
Abstract
INTRODUCTION Alcohol use can be significantly associated with negative social, professional, and health outcomes. Even more so, alcohol use disorder (AUD) is a critical public health issue and major avoidable risk factor. This study aimed to examine the effect of a naturalistic psychedelic experience on alcohol use and related measures. METHODS A retrospective online survey was conducted on 160 individuals who reported a psychedelic experience and a concomitant drinking habit but did not necessarily have an AUD. Demographic data, characteristics of the psychedelic experience, and changes in alcohol consumption and psychological flexibility were surveyed. Results: The mean number of drinking days per week and AUDIT scores significantly decreased after the psychedelic experience (P < .001). Subjects who quit or reduced drinking had a more severe AUD (P < .01) and lower psychological flexibility (P = .003) before the psychedelic session. Alcohol use reduction was significantly associated with the intensity of the mystical experience (P = .03). Psychological flexibility increased more in participants who reduced their alcohol use (P < .001), and the change in psychological flexibility was one of the predictors of alcohol use improvement (P = .003). Conclusion: Our findings suggest that a naturalistic psychedelic experience could be associated with a reduction in alcohol use and dependency. Such positive health outcomes can be associated with the intensity of the mystical experience as well as an increase in psychological flexibility.
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Affiliation(s)
- Ewen Kervadec
- Department of Psychiatry and Addictology, APHP, Paul Brousse Hospital, Villejuif F-94800, France
| | - Baptiste Fauvel
- Laboratoire Mémoire, Cerveau et Cognition (UR 7536), Institut de Psychologie, Université Paris Cité, Site Boulogne-Centre Henri Pié ron71, avenue Edouard Vaillant 92774 Boulogne-Billancourt, Paris, France
| | - Lana Strika-Bruneau
- Department of Psychiatry and Addictology, APHP, Paul Brousse Hospital, Villejuif F-94800, France
- Unité de Recherche Psychiatrie-Comorbidités-Addictions-PSYCOMADD-Paris Saclay University Île-de-France, Hôpital Paul Brousse AP-HP12 Avenue Paul Vaillant Couturier, 94800 Villejuif, France
| | - Ammar Amirouche
- Department of Psychiatry and Addictology, APHP, Paul Brousse Hospital, Villejuif F-94800, France
- Unité de Recherche Psychiatrie-Comorbidités-Addictions-PSYCOMADD-Paris Saclay University Île-de-France, Hôpital Paul Brousse AP-HP12 Avenue Paul Vaillant Couturier, 94800 Villejuif, France
| | - Vincent Verroust
- Unité de Recherche Psychiatrie-Comorbidités-Addictions-PSYCOMADD-Paris Saclay University Île-de-France, Hôpital Paul Brousse AP-HP12 Avenue Paul Vaillant Couturier, 94800 Villejuif, France
- Université Picardie-Jules Vernes, Chemin du Thil, 80000 Amiens, France
| | - Pascale Piolino
- Laboratoire Mémoire, Cerveau et Cognition (UR 7536), Institut de Psychologie, Université Paris Cité, Site Boulogne-Centre Henri Pié ron71, avenue Edouard Vaillant 92774 Boulogne-Billancourt, Paris, France
| | - Bruno Romeo
- Department of Psychiatry and Addictology, APHP, Paul Brousse Hospital, Villejuif F-94800, France
- Unité de Recherche Psychiatrie-Comorbidités-Addictions-PSYCOMADD-Paris Saclay University Île-de-France, Hôpital Paul Brousse AP-HP12 Avenue Paul Vaillant Couturier, 94800 Villejuif, France
| | - Amine Benyamina
- Department of Psychiatry and Addictology, APHP, Paul Brousse Hospital, Villejuif F-94800, France
- Unité de Recherche Psychiatrie-Comorbidités-Addictions-PSYCOMADD-Paris Saclay University Île-de-France, Hôpital Paul Brousse AP-HP12 Avenue Paul Vaillant Couturier, 94800 Villejuif, France
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Schoeller F, Jain A, Adrien V, Maes P, Reggente N. Aesthetic chills mitigate maladaptive cognition in depression. BMC Psychiatry 2024; 24:40. [PMID: 38200491 PMCID: PMC10782525 DOI: 10.1186/s12888-023-05476-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Accepted: 12/23/2023] [Indexed: 01/12/2024] Open
Abstract
BACKGROUND Depression is a major global health challenge, affecting over 300 million people worldwide. Current pharmacological and psychotherapeutic interventions have limited efficacy, underscoring the need for novel approaches. Emerging evidence suggests that peak emotional experiences characterized by awe, transcendence, and meaning hold promise for rapidly shifting maladaptive cognitive patterns in depression. Aesthetic chills, a peak positive emotion characterized by physical sensations such as shivers and goosebumps, may influence reward-related neural pathways and hold promise for modifying core maladaptive beliefs rooted in early adverse experiences. METHODS We enrolled 96 patients diagnosed with major depressive disorder. A validated database of multimedia known to elicit chills responses (ChillsDB) was used for stimulus presentation. Participants' emotional responses were assessed using the Emotional Breakthrough Inventory (EBI), while shifts in self-schema were measured via the Young Positive Schema Questionnaire (YSPQ). RESULTS The study found that chill-inducing stimuli have the potential to positively influence the core schema of individuals with depression, impacting areas of self-related beliefs. The associated phenomenology triggered by chills appears to share similarities with the altered states of consciousness induced by psychedelic substances like psilocybin. CONCLUSIONS These preliminary results suggest that the biological processes involved in aesthetic chills could be harnessed as a non-pharmacological intervention for depression. However, further investigation is necessary to comprehensively understand the neurophysiological responses to chills and to evaluate the practicality, effectiveness, and safety of utilizing aesthetic chills as a preventive measure in mental health care.
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Affiliation(s)
- Felix Schoeller
- Massachusetts Institute of Technology, Cambridge, MA, USA.
- Institute for Advanced Consciousness Studies, Santa Monica, CA, USA.
| | | | - Vladimir Adrien
- Department of Infectious and Tropical Diseases, AP-HP, Avicenne Hospital, Université Sorbonne Paris Nord, Bobigny, F-93000, France
- Institute of Psychiatry and Neuroscience of Paris (IPNP), Université Paris Cité, Inserm UMR-S 1266, Team Membrane Traffic in Healthy & Diseased Brain, Paris, 75014, France
| | - Pattie Maes
- Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Nicco Reggente
- Institute for Advanced Consciousness Studies, Santa Monica, CA, USA
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Beans C. If psychedelics heal, how do they do it? Proc Natl Acad Sci U S A 2024; 121:e2321906121. [PMID: 38170743 PMCID: PMC10786285 DOI: 10.1073/pnas.2321906121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2024] Open
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Stoliker D, Novelli L, Vollenweider FX, Egan GF, Preller KH, Razi A. Neural Mechanisms of Resting-State Networks and the Amygdala Underlying the Cognitive and Emotional Effects of Psilocybin. Biol Psychiatry 2024:S0006-3223(24)00004-0. [PMID: 38185235 DOI: 10.1016/j.biopsych.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 12/19/2023] [Accepted: 01/02/2024] [Indexed: 01/09/2024]
Abstract
BACKGROUND Serotonergic psychedelics, such as psilocybin, alter perceptual and cognitive systems that are functionally integrated with the amygdala. These changes can alter cognition and emotions that are hypothesized to contribute to their therapeutic utility. However, the neural mechanisms of cognitive and subcortical systems altered by psychedelics are not well understood. METHODS We used resting-state functional magnetic resonance images collected during a randomized, double-blind, placebo-controlled clinical trial of 24 healthy adults under 0.2 mg/kg psilocybin to estimate the directed (i.e., effective) changes between the amygdala and 3 large-scale resting-state networks involved in cognition. These networks are the default mode network, the salience network, and the central executive network. RESULTS We found a pattern of decreased top-down effective connectivity from these resting-state networks to the amygdala. Effective connectivity decreased within the default mode network and salience network but increased within the central executive network. These changes in effective connectivity were statistically associated with behavioral measures of altered cognition and emotion under the influence of psilocybin. CONCLUSIONS Our findings suggest that temporary amygdala signal attenuation is associated with mechanistic changes to resting-state network connectivity. These changes are significant for altered cognition and perception and suggest targets for research investigating the efficacy of psychedelic therapy for internalizing psychiatric disorders. More broadly, our study suggests the value of quantifying the brain's hierarchical organization using effective connectivity to identify important mechanisms for basic cognitive function and how they are integrated to give rise to subjective experiences.
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Affiliation(s)
- Devon Stoliker
- Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, Australia; Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
| | - Leonardo Novelli
- Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, Australia; Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
| | - Franz X Vollenweider
- Department of Psychiatry, Psychotherapy & Psychosomatics, Psychiatric University Hospital Zurich, Zurich, Switzerland
| | - Gary F Egan
- Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, Australia; Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia
| | - Katrin H Preller
- Department of Psychiatry, Psychotherapy & Psychosomatics, Psychiatric University Hospital Zurich, Zurich, Switzerland
| | - Adeel Razi
- Turner Institute for Brain and Mental Health, Monash University, Clayton, Victoria, Australia; Monash Biomedical Imaging, Monash University, Clayton, Victoria, Australia; Wellcome Centre for Human Neuroimaging, University College London, London, United Kingdom; CIFAR Azrieli Global Scholars Program, CIFAR, Toronto, Ontario, Canada.
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Luppi AI, Girn M, Rosas FE, Timmermann C, Roseman L, Erritzoe D, Nutt DJ, Stamatakis EA, Spreng RN, Xing L, Huttner WB, Carhart-Harris RL. A role for the serotonin 2A receptor in the expansion and functioning of human transmodal cortex. Brain 2024; 147:56-80. [PMID: 37703310 DOI: 10.1093/brain/awad311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2023] [Revised: 08/14/2023] [Accepted: 08/18/2023] [Indexed: 09/15/2023] Open
Abstract
Integrating independent but converging lines of research on brain function and neurodevelopment across scales, this article proposes that serotonin 2A receptor (5-HT2AR) signalling is an evolutionary and developmental driver and potent modulator of the macroscale functional organization of the human cerebral cortex. A wealth of evidence indicates that the anatomical and functional organization of the cortex follows a unimodal-to-transmodal gradient. Situated at the apex of this processing hierarchy-where it plays a central role in the integrative processes underpinning complex, human-defining cognition-the transmodal cortex has disproportionately expanded across human development and evolution. Notably, the adult human transmodal cortex is especially rich in 5-HT2AR expression and recent evidence suggests that, during early brain development, 5-HT2AR signalling on neural progenitor cells stimulates their proliferation-a critical process for evolutionarily-relevant cortical expansion. Drawing on multimodal neuroimaging and cross-species investigations, we argue that, by contributing to the expansion of the human cortex and being prevalent at the apex of its hierarchy in the adult brain, 5-HT2AR signalling plays a major role in both human cortical expansion and functioning. Owing to its unique excitatory and downstream cellular effects, neuronal 5-HT2AR agonism promotes neuroplasticity, learning and cognitive and psychological flexibility in a context-(hyper)sensitive manner with therapeutic potential. Overall, we delineate a dual role of 5-HT2ARs in enabling both the expansion and modulation of the human transmodal cortex.
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Affiliation(s)
- Andrea I Luppi
- Department of Clinical Neurosciences and Division of Anaesthesia, University of Cambridge, Cambridge, CB2 0QQ, UK
- Leverhulme Centre for the Future of Intelligence, University of Cambridge, Cambridge, CB2 1SB, UK
- The Alan Turing Institute, London, NW1 2DB, UK
| | - Manesh Girn
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, H3A 2B4, Canada
- Psychedelics Division-Neuroscape, Department of Neurology, University of California SanFrancisco, San Francisco, CA 94158, USA
| | - Fernando E Rosas
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
- Data Science Institute, Imperial College London, London, SW7 2AZ, UK
- Centre for Complexity Science, Imperial College London, London, SW7 2AZ, UK
| | - Christopher Timmermann
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
| | - Leor Roseman
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
| | - David Erritzoe
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
| | - David J Nutt
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
| | - Emmanuel A Stamatakis
- Department of Clinical Neurosciences and Division of Anaesthesia, University of Cambridge, Cambridge, CB2 0QQ, UK
| | - R Nathan Spreng
- Montreal Neurological Institute, Department of Neurology and Neurosurgery, McGill University, Montreal, H3A 2B4, Canada
| | - Lei Xing
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, 01307, Germany
| | - Wieland B Huttner
- Max Planck Institute of Molecular Cell Biology and Genetics, Dresden, 01307, Germany
| | - Robin L Carhart-Harris
- Psychedelics Division-Neuroscape, Department of Neurology, University of California SanFrancisco, San Francisco, CA 94158, USA
- Centre for Psychedelic Research, Department of Brain Sciences, Faculty of Medicine, Imperial College London, London, SW7 2AZ, UK
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Suzuki K, Seth AK, Schwartzman DJ. Modelling phenomenological differences in aetiologically distinct visual hallucinations using deep neural networks. Front Hum Neurosci 2024; 17:1159821. [PMID: 38234594 PMCID: PMC10791985 DOI: 10.3389/fnhum.2023.1159821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 09/11/2023] [Indexed: 01/19/2024] Open
Abstract
Visual hallucinations (VHs) are perceptions of objects or events in the absence of the sensory stimulation that would normally support such perceptions. Although all VHs share this core characteristic, there are substantial phenomenological differences between VHs that have different aetiologies, such as those arising from Neurodegenerative conditions, visual loss, or psychedelic compounds. Here, we examine the potential mechanistic basis of these differences by leveraging recent advances in visualising the learned representations of a coupled classifier and generative deep neural network-an approach we call 'computational (neuro)phenomenology'. Examining three aetiologically distinct populations in which VHs occur-Neurodegenerative conditions (Parkinson's Disease and Lewy Body Dementia), visual loss (Charles Bonnet Syndrome, CBS), and psychedelics-we identified three dimensions relevant to distinguishing these classes of VHs: realism (veridicality), dependence on sensory input (spontaneity), and complexity. By selectively tuning the parameters of the visualisation algorithm to reflect influence along each of these phenomenological dimensions we were able to generate 'synthetic VHs' that were characteristic of the VHs experienced by each aetiology. We verified the validity of this approach experimentally in two studies that examined the phenomenology of VHs in Neurodegenerative and CBS patients, and in people with recent psychedelic experience. These studies confirmed the existence of phenomenological differences across these three dimensions between groups, and crucially, found that the appropriate synthetic VHs were rated as being representative of each group's hallucinatory phenomenology. Together, our findings highlight the phenomenological diversity of VHs associated with distinct causal factors and demonstrate how a neural network model of visual phenomenology can successfully capture the distinctive visual characteristics of hallucinatory experience.
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Affiliation(s)
- Keisuke Suzuki
- Sussex Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Department of Informatics, University of Sussex, Brighton, United Kingdom
- Center for Human Nature, Artificial Intelligence and Neuroscience (CHAIN), Hokkaido University, Sapporo, Japan
| | - Anil K. Seth
- Sussex Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Department of Informatics, University of Sussex, Brighton, United Kingdom
- Program on Brain, Mind, and Consciousness, Canadian Institute for Advanced Research, Toronto, ON, Canada
| | - David J. Schwartzman
- Sussex Centre for Consciousness Science, University of Sussex, Brighton, United Kingdom
- Department of Informatics, University of Sussex, Brighton, United Kingdom
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Ivan VE, Tomàs-Cuesta DP, Esteves IM, Curic D, Mohajerani M, McNaughton BL, Davidsen J, Gruber AJ. The Nonclassic Psychedelic Ibogaine Disrupts Cognitive Maps. Biol Psychiatry Glob Open Sci 2024; 4:275-283. [PMID: 38298796 PMCID: PMC10829624 DOI: 10.1016/j.bpsgos.2023.07.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 07/20/2023] [Accepted: 07/23/2023] [Indexed: 02/02/2024] Open
Abstract
Background The ability of psychedelic compounds to profoundly alter mental function has been long known, but the underlying changes in cellular-level information encoding remain poorly understood. Methods We used two-photon microscopy to record from the retrosplenial cortex in head-fixed mice running on a treadmill before and after injection of the nonclassic psychedelic ibogaine (40 mg/kg intraperitoneally). Results We found that the cognitive map, formed by the representation of position encoded by ensembles of individual neurons in the retrosplenial cortex, was destabilized by ibogaine when mice had to infer position between tactile landmarks. This corresponded with increased neural activity rates, loss of correlation structure, and increased responses to cues. Ibogaine had surprisingly little effect on the size-frequency distribution of network activity events, suggesting that signal propagation within the retrosplenial cortex was largely unaffected. Conclusions Taken together, these data support proposals that compounds with psychedelic properties disrupt representations that are important for constraining neocortical activity, thereby increasing the entropy of neural signaling. Furthermore, the loss of expected position encoding between landmarks recapitulated effects of hippocampal impairment, suggesting that disruption of cognitive maps or other hippocampal processing may be a contributing mechanism of discoordinated neocortical activity in psychedelic states.
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Affiliation(s)
- Victorita E. Ivan
- Canadian Center for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
| | - David P. Tomàs-Cuesta
- Canadian Center for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Ingrid M. Esteves
- Canadian Center for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Davor Curic
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - Majid Mohajerani
- Canadian Center for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
| | - Bruce L. McNaughton
- Canadian Center for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
- Center for the Neurobiology of Learning and Memory, University of California Irvine, Irvine, California
| | - Joern Davidsen
- Department of Physics and Astronomy, University of Calgary, Calgary, Alberta, Canada
| | - Aaron J. Gruber
- Canadian Center for Behavioural Neuroscience, Department of Neuroscience, University of Lethbridge, Lethbridge, Alberta, Canada
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42
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Heifets BD, Olson DE. Therapeutic mechanisms of psychedelics and entactogens. Neuropsychopharmacology 2024; 49:104-118. [PMID: 37488282 PMCID: PMC10700553 DOI: 10.1038/s41386-023-01666-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 07/10/2023] [Accepted: 07/11/2023] [Indexed: 07/26/2023]
Abstract
Recent clinical and preclinical evidence suggests that psychedelics and entactogens may produce both rapid and sustained therapeutic effects across several indications. Currently, there is a disconnect between how these compounds are used in the clinic and how they are studied in preclinical species, which has led to a gap in our mechanistic understanding of how these compounds might positively impact mental health. Human studies have emphasized extra-pharmacological factors that could modulate psychedelic-induced therapeutic responses including set, setting, and integration-factors that are poorly modelled in current animal experiments. In contrast, animal studies have focused on changes in neuronal activation and structural plasticity-outcomes that are challenging to measure in humans. Here, we describe several hypotheses that might explain how psychedelics rescue neuropsychiatric disease symptoms, and we propose ways to bridge the gap between human and rodent studies. Given the diverse pharmacological profiles of psychedelics and entactogens, we suggest that their rapid and sustained therapeutic mechanisms of action might best be described by the collection of circuits that they modulate rather than their actions at any single molecular target. Thus, approaches focusing on selective circuit modulation of behavioral phenotypes might prove more fruitful than target-based methods for identifying novel compounds with rapid and sustained therapeutic effects similar to psychedelics and entactogens.
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Affiliation(s)
- Boris D Heifets
- Department of Anesthesiology, Perioperative and Pain Medicine, Stanford University School of Medicine, Stanford, CA, 94305, USA.
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA, 94305, USA.
| | - David E Olson
- Institute for Psychedelics and Neurotherapeutics, University of California, Davis, Davis, CA, 95616, USA.
- Department of Chemistry, University of California, Davis, Davis, CA, 95616, USA.
- Center for Neuroscience, University of California, Davis, Davis, CA, 95618, USA.
- Department of Biochemistry and Molecular Medicine, School of Medicine, University of California, Davis, Sacramento, CA, 95817, USA.
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43
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Wolinsky D, Barrett FS, Vandrey R. The psychedelic effects of cannabis: A review of the literature. J Psychopharmacol 2024; 38:49-55. [PMID: 37947321 DOI: 10.1177/02698811231209194] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2023]
Abstract
Cannabis and classic psychedelics are controlled substances with emerging evidence of efficacy in the treatment of a variety of psychiatric illnesses. Cannabis has largely not been regarded as having psychedelic effects in contemporary literature, despite many examples of historical use along with classic psychedelics to attain altered states of consciousness. Research into the "psychedelic" effects of cannabis, and delta-9-tetrahydrocannabinol (THC) in particular, could prove helpful for assessing potential therapeutic indications and elucidating the mechanism of action of both cannabis and classic psychedelics. This review aggregates and evaluates the literature assessing the capacity of cannabis to yield the perceptual changes, aversiveness, and mystical experiences more typically associated with classic psychedelics such as psilocybin. This review also provides a brief contrast of neuroimaging findings associated with the acute effects of cannabis and psychedelics. The available evidence suggests that high-THC cannabis may be able to elicit psychedelic effects, but that these effects may not have been observed in recent controlled research studies due to the doses, set, and settings commonly used. Research is needed to investigate the effects of high doses of THC in the context utilized in therapeutic studies of psychedelics aimed to occasion psychedelic and/or therapeutic experiences. If cannabis can reliably generate psychedelic experiences under these conditions, high-THC dose cannabis treatments should be explored as potential adjunctive treatments for psychiatric disorders and be considered as an active comparator in clinical trials involving traditional psychedelic medications.
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Affiliation(s)
- David Wolinsky
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
| | - Frederick Streeter Barrett
- Department of Psychiatry and Behavioral Sciences, Center for Psychedelic and Consciousness Research, Behavioral Pharmacology Research Unit, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Department of Psychological & Brain Sciences, Krieger School of Arts & Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Ryan Vandrey
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD, USA
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Jerotic K, Vuust P, Kringelbach ML. Psychedelia: The interplay of music and psychedelics. Ann N Y Acad Sci 2024; 1531:12-28. [PMID: 37983198 DOI: 10.1111/nyas.15082] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Music and psychedelics have been intertwined throughout the existence of Homo sapiens, from the early shamanic rituals of the Americas and Africa to the modern use of psychedelic-assisted therapy for a variety of mental health conditions. Across such settings, music has been highly prized for its ability to guide the psychedelic experience. Here, we examine the interplay between music and psychedelics, starting by describing their association with the brain's functional hierarchy that is relied upon for music perception and its psychedelic-induced manipulation, as well as an exploration of the limited research on their mechanistic neural overlap. We explore music's role in Western psychedelic therapy and the use of music in indigenous psychedelic rituals, with a specific focus on ayahuasca and the Santo Daime Church. Furthermore, we explore work relating to the evolution and onset of music and psychedelic use. Finally, we consider music's potential to lead to altered states of consciousness in the absence of psychedelics as well as the development of psychedelic music. Here, we provide an overview of several perspectives on the interaction between psychedelic use and music-a topic with growing interest given increasing excitement relating to the therapeutic efficacy of psychedelic interventions.
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Affiliation(s)
- Katarina Jerotic
- Centre for Eudaimonia and Human Flourishing, Linacre College, University of Oxford, Oxford, UK
- Department of Psychiatry, University of Oxford, Oxford, UK
- Center for Music in the Brain, Department of Clinical Medicine, Aarhus University & The Royal Academy of Music Aarhus/Aalborg, Aarhus, Denmark
| | - Peter Vuust
- Center for Music in the Brain, Department of Clinical Medicine, Aarhus University & The Royal Academy of Music Aarhus/Aalborg, Aarhus, Denmark
| | - Morten L Kringelbach
- Centre for Eudaimonia and Human Flourishing, Linacre College, University of Oxford, Oxford, UK
- Department of Psychiatry, University of Oxford, Oxford, UK
- Center for Music in the Brain, Department of Clinical Medicine, Aarhus University & The Royal Academy of Music Aarhus/Aalborg, Aarhus, Denmark
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45
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Zaretsky TG, Jagodnik KM, Barsic R, Antonio JH, Bonanno PA, MacLeod C, Pierce C, Carney H, Morrison MT, Saylor C, Danias G, Lepow L, Yehuda R. The Psychedelic Future of Post-Traumatic Stress Disorder Treatment. Curr Neuropharmacol 2024; 22:636-735. [PMID: 38284341 PMCID: PMC10845102 DOI: 10.2174/1570159x22666231027111147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 09/11/2023] [Accepted: 09/13/2023] [Indexed: 01/30/2024] Open
Abstract
Post-traumatic stress disorder (PTSD) is a mental health condition that can occur following exposure to a traumatic experience. An estimated 12 million U.S. adults are presently affected by this disorder. Current treatments include psychological therapies (e.g., exposure-based interventions) and pharmacological treatments (e.g., selective serotonin reuptake inhibitors (SSRIs)). However, a significant proportion of patients receiving standard-of-care therapies for PTSD remain symptomatic, and new approaches for this and other trauma-related mental health conditions are greatly needed. Psychedelic compounds that alter cognition, perception, and mood are currently being examined for their efficacy in treating PTSD despite their current status as Drug Enforcement Administration (DEA)- scheduled substances. Initial clinical trials have demonstrated the potential value of psychedelicassisted therapy to treat PTSD and other psychiatric disorders. In this comprehensive review, we summarize the state of the science of PTSD clinical care, including current treatments and their shortcomings. We review clinical studies of psychedelic interventions to treat PTSD, trauma-related disorders, and common comorbidities. The classic psychedelics psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT) and DMT-containing ayahuasca, as well as the entactogen 3,4-methylenedioxymethamphetamine (MDMA) and the dissociative anesthetic ketamine, are reviewed. For each drug, we present the history of use, psychological and somatic effects, pharmacology, and safety profile. The rationale and proposed mechanisms for use in treating PTSD and traumarelated disorders are discussed. This review concludes with an in-depth consideration of future directions for the psychiatric applications of psychedelics to maximize therapeutic benefit and minimize risk in individuals and communities impacted by trauma-related conditions.
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Affiliation(s)
- Tamar Glatman Zaretsky
- James J. Peters Veterans Affairs Medical Center, New York, NY, USA
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Kathleen M. Jagodnik
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Robert Barsic
- James J. Peters Veterans Affairs Medical Center, New York, NY, USA
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Josimar Hernandez Antonio
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Philip A. Bonanno
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Carolyn MacLeod
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Charlotte Pierce
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Hunter Carney
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Morgan T. Morrison
- James J. Peters Veterans Affairs Medical Center, New York, NY, USA
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Charles Saylor
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - George Danias
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Lauren Lepow
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Rachel Yehuda
- James J. Peters Veterans Affairs Medical Center, New York, NY, USA
- The Center for Psychedelic Psychotherapy and Trauma Research, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Icahn School of Medicine at Mount Sinai, New York, NY, USA
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46
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Mallaroni P, Mason NL, Kloft L, Reckweg JT, van Oorsouw K, Toennes SW, Tolle HM, Amico E, Ramaekers JG. Shared functional connectome fingerprints following ritualistic ayahuasca intake. Neuroimage 2024; 285:120480. [PMID: 38061689 DOI: 10.1016/j.neuroimage.2023.120480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Revised: 11/06/2023] [Accepted: 11/29/2023] [Indexed: 01/13/2024] Open
Abstract
The knowledge that brain functional connectomes are unique and reliable has enabled behaviourally relevant inferences at a subject level. However, whether such "fingerprints" persist under altered states of consciousness is unknown. Ayahuasca is a potent serotonergic psychedelic which produces a widespread dysregulation of functional connectivity. Used communally in religious ceremonies, its shared use may highlight relevant novel interactions between mental state and functional connectome (FC) idiosyncrasy. Using 7T fMRI, we assessed resting-state static and dynamic FCs for 21 Santo Daime members after collective ayahuasca intake in an acute, within-subject study. Here, connectome fingerprinting revealed FCs showed reduced idiosyncrasy, accompanied by a spatiotemporal reallocation of keypoint edges. Importantly, we show that interindividual differences in higher-order FC motifs are relevant to experiential phenotypes, given that they can predict perceptual drug effects. Collectively, our findings offer an example of how individualised connectivity markers can be used to trace a subject's FC across altered states of consciousness.
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Affiliation(s)
- Pablo Mallaroni
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands.
| | - Natasha L Mason
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - Lilian Kloft
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - Johannes T Reckweg
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands
| | - Kim van Oorsouw
- Department of Forensic Psychology, Faculty of Psychology and Neuroscience, Maastricht University, the Netherlands
| | - Stefan W Toennes
- Institute of Legal Medicine, University Hospital, Goethe University, Frankfurt/Main, Germany
| | | | | | - Johannes G Ramaekers
- Department of Neuropsychology and Psychopharmacology, Faculty of Psychology and Neuroscience, Maastricht University, P.O. Box 616, 6200 MD, Maastricht, the Netherlands
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47
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Thal SB, Baker P, Marinis J, Wieberneit M, Sharbanee JM, Bruno R, Skeffington PM, Bright SJ. Therapeutic frameworks in integration sessions in substance-assisted psychotherapy: A systematised review. Clin Psychol Psychother 2023. [PMID: 38148518 DOI: 10.1002/cpp.2945] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 11/07/2023] [Accepted: 11/24/2023] [Indexed: 12/28/2023]
Abstract
Serotonergic psychedelics and related substances have been explored as potential adjuncts in substance-assisted psychotherapy (SAPT) for treating various disorders. SAPT can be divided into three phases: preparation, administration and integration. Integration is commonly defined as the comprehension and effective application of insights from psychedelic experiences into everyday life. However, there is limited research regarding the most appropriate therapeutic approach during SAPT. In this article, we discuss the current evidence for different therapeutic frameworks for integration sessions when serotonergic psychedelics and entactogens are used as adjuncts to psychotherapy. We conducted a systematised review of the literature following PRISMA guidelines and searched PsycINFO, MEDLINE and Cochrane Library databases. The final synthesis included 75 clinical trials, mixed-methods investigations, treatment manuals, study protocols, quasi-experiments, qualitative investigations, descriptive studies, opinion papers, reviews, books and book chapters, published until 11 November 2022. The effects that various therapeutic approaches for integration sessions have on therapeutic outcomes have not been investigated by means of rigorous research. Most of the available evidence we retrieved was not supported by empirical data, thus limiting any conclusive statements regarding appropriate therapeutic frameworks for integration sessions for SAPT. Current clinical studies have used a range of therapeutic frameworks with the majority drawing from the humanistic-experiential tradition. While integration is regarded as crucial for the safe application of SAPT, there is currently an insufficient evidence base to suggest that any type of therapy is effective for guiding integration sessions. A systematic investigation of different therapeutic frameworks for integration and additional therapy-related factors is needed.
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Affiliation(s)
- Sascha B Thal
- Curtin School of Population Health, Curtin University, Bentley, Western Australia, Australia
- School of Psychology, College of Health & Education, Murdoch University, Murdoch, Western Australia, Australia
| | - Paris Baker
- School of Medicine (Psychology), University of Tasmania, Hobart, Tasmania, Australia
| | - Jonathon Marinis
- Orygen Youth Health, University of Melbourne, Parkville, Victoria, Australia
| | - Michelle Wieberneit
- Law School, University of Western Australia, Crawley, Western Australia, Australia
| | - Jason M Sharbanee
- Enable Institute, Discipline of Psychology, Curtin School of Population Health, Curtin University, Bentley, Western Australia, Australia
| | - Raimundo Bruno
- School of Medicine (Psychology), University of Tasmania, Hobart, Tasmania, Australia
| | - Petra M Skeffington
- School of Psychology, College of Health & Education, Murdoch University, Murdoch, Western Australia, Australia
| | - Stephen J Bright
- School of Medical and Health Sciences, Edith Cowan University, Joondalup, Western Australia, Australia
- Psychedelic Research in Science and Medicine (PRISM), Balwyn North, Victoria, Australia
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Reinwald JR, Schmitz CN, Skorodumov I, Kuchar M, Weber-Fahr W, Spanagel R, Meinhardt MW. Psilocybin-induced default mode network hypoconnectivity is blunted in alcohol-dependent rats. Transl Psychiatry 2023; 13:392. [PMID: 38097569 PMCID: PMC10721862 DOI: 10.1038/s41398-023-02690-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2023] [Revised: 11/15/2023] [Accepted: 11/27/2023] [Indexed: 12/17/2023] Open
Abstract
Alcohol Use Disorder (AUD) adversely affects the lives of millions of people, but still lacks effective treatment options. Recent advancements in psychedelic research suggest psilocybin to be potentially efficacious for AUD. However, major knowledge gaps remain regarding (1) psilocybin's general mode of action and (2) AUD-specific alterations of responsivity to psilocybin treatment in the brain that are crucial for treatment development. Here, we conducted a randomized, placebo-controlled crossover pharmaco-fMRI study on psilocybin effects using a translational approach with healthy rats and a rat model of alcohol relapse. Psilocybin effects were quantified with resting-state functional connectivity using data-driven whole-brain global brain connectivity, network-based statistics, graph theory, hypothesis-driven Default Mode Network (DMN)-specific connectivity, and entropy analyses. Results demonstrate that psilocybin induced an acute wide-spread decrease in different functional connectivity domains together with a distinct increase of connectivity between serotonergic core regions and cortical areas. We could further provide translational evidence for psilocybin-induced DMN hypoconnectivity reported in humans. Psilocybin showed an AUD-specific blunting of DMN hypoconnectivity, which strongly correlated to the alcohol relapse intensity and was mainly driven by medial prefrontal regions. In conclusion, our results provide translational validity for acute psilocybin-induced neural effects in the rodent brain. Furthermore, alcohol relapse severity was negatively correlated with neural responsivity to psilocybin treatment. Our data suggest that a clinical standard dose of psilocybin may not be sufficient to treat severe AUD cases; a finding that should be considered for future clinical trials.
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Affiliation(s)
- Jonathan R Reinwald
- Research Group Translational Imaging, Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
- Research Group Systems Neuroscience and Mental Health, Department of Psychiatry and Psychotherapy, University Medical Center Mainz, Johannes Gutenberg University, Mainz, Germany
| | - Christian N Schmitz
- Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
- Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Ivan Skorodumov
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Martin Kuchar
- Forensic Laboratory of Biologically Active Substances, Department of Chemistry of Natural Compounds, University of Chemistry and Technology Prague, Prague, Czech Republic
- Psychedelics Research Centre, National Institute of Mental Health, Klecany, Czech Republic
| | - Wolfgang Weber-Fahr
- Research Group Translational Imaging, Department of Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany
| | - Rainer Spanagel
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany.
| | - Marcus W Meinhardt
- Department of Molecular Neuroimaging, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany.
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim, University of Heidelberg, Heidelberg, Germany.
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Onofrj M, Russo M, Delli Pizzi S, De Gregorio D, Inserra A, Gobbi G, Sensi SL. The central role of the Thalamus in psychosis, lessons from neurodegenerative diseases and psychedelics. Transl Psychiatry 2023; 13:384. [PMID: 38092757 PMCID: PMC10719401 DOI: 10.1038/s41398-023-02691-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Revised: 11/06/2023] [Accepted: 11/27/2023] [Indexed: 12/17/2023] Open
Abstract
The PD-DLB psychosis complex found in Parkinson's disease (PD) and Dementia with Lewy Bodies (DLB) includes hallucinations, Somatic Symptom/Functional Disorders, and delusions. These disorders exhibit similar presentation patterns and progression. Mechanisms at the root of these symptoms also share similarities with processes promoting altered states of consciousness found in Rapid Eye Movement sleep, psychiatric disorders, or the intake of psychedelic compounds. We propose that these mechanisms find a crucial driver and trigger in the dysregulated activity of high-order thalamic nuclei set in motion by ThalamoCortical Dysrhythmia (TCD). TCD generates the loss of finely tuned cortico-cortical modulations promoted by the thalamus and unleashes the aberrant activity of the Default Mode Network (DMN). TCD moves in parallel with altered thalamic filtering of external and internal information. The process produces an input overload to the cortex, thereby exacerbating DMN decoupling from task-positive networks. These phenomena alter the brain metastability, creating dreamlike, dissociative, or altered states of consciousness. In support of this hypothesis, mind-altering psychedelic drugs also modulate thalamic-cortical pathways. Understanding the pathophysiological background of these conditions provides a conceptual bridge between neurology and psychiatry, thereby helping to generate a promising and converging area of investigation and therapeutic efforts.
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Affiliation(s)
- Marco Onofrj
- Behavioral Neurology and Molecular Neurology Units, Center for Advanced Studies and Technology - CAST, Institute for Advanced Biomedical Technology-ITAB University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
| | - Mirella Russo
- Behavioral Neurology and Molecular Neurology Units, Center for Advanced Studies and Technology - CAST, Institute for Advanced Biomedical Technology-ITAB University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Stefano Delli Pizzi
- Behavioral Neurology and Molecular Neurology Units, Center for Advanced Studies and Technology - CAST, Institute for Advanced Biomedical Technology-ITAB University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy
| | - Danilo De Gregorio
- Division of Neuroscience, Vita-Salute San Raffaele University, Milan, Italy
| | - Antonio Inserra
- Neurobiological Psychiatry Unit, McGill University, Montreal, QC, Canada
| | - Gabriella Gobbi
- Neurobiological Psychiatry Unit, McGill University, Montreal, QC, Canada
| | - Stefano L Sensi
- Behavioral Neurology and Molecular Neurology Units, Center for Advanced Studies and Technology - CAST, Institute for Advanced Biomedical Technology-ITAB University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
- Department of Neuroscience, Imaging, and Clinical Sciences, University G. d'Annunzio of Chieti-Pescara, Chieti, Italy.
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McNamara P. Religion and the brain: Jordan Grafman's contributions to religion and brain research and the special case of religious language. Cortex 2023; 169:374-379. [PMID: 37995522 DOI: 10.1016/j.cortex.2023.10.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 09/12/2023] [Accepted: 10/26/2023] [Indexed: 11/25/2023]
Abstract
Grafman and colleagues' papers in religion and brain research have documented the extent to which religious beliefs and behaviors are mediated by standard social cognitive networks in brain. Grafman's work however also points beyond treatments of religious cognition as merely a species of more general social cognitive processes. Data emerging from experiments targeting mystical states as well as reports of encounters with supernatural agents during controlled experiments with psychedelics, suggest that brain mediation of mystical encounters with supernatural agents involves both disruption/downregulation of social cognitive networks and activation of an additional as yet only partially identified neural process suggesting that a full neuroscience account of religious beliefs, behaviors and experiences must extend beyond treatment of religion as an ordinary social process.
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Affiliation(s)
- Patrick McNamara
- Department of Psychology, National University, USA; Boston University School of Medicine, USA; Boston University School of Theology, USA; Co-PI Cognitive Neuroscience of Religious Cognition (CNRC) Project, USA; Center for Mind and Culture, Boston, MA, USA.
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