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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] [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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Low F, Earleywine M. Educational Materials and Image Induction Increase Treatment Credibility. J Psychoactive Drugs 2024; 56:56-65. [PMID: 36682063 DOI: 10.1080/02791072.2022.2154722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2022] [Revised: 10/02/2022] [Accepted: 10/19/2022] [Indexed: 01/23/2023]
Abstract
Patient-perceived treatment credibility is linked to important outcome measures including symptom reduction, therapeutic alliance, patient satisfaction, and attrition rates. However, few studies have tested strategies to enhance treatment credibility. The present study investigates the effect of brief, written educational materials and the use of an image induction prime on perceptions of credibility for cognitive behavioral therapy and psilocybin-assisted therapy for depression. Participants (N = 493) rated the perceived credibility of depression treatments before and after reading brief educational materials. Half of the participants were asked an image induction question containing the construct of open-mindedness. Results indicate that brief educational materials of about 300 words significantly increased perceived treatment credibility for both therapies, with a large effect size (Cohen's d = .91). The use of an image induction prime further increased perceived credibility for psilocybin-assisted therapy for depression (Cohen's d = .38). These strategies offer an efficient and cost-effective way to enhance treatment credibility. Future studies testing variations of the image induction prime might prove fruitful for optimizing the technique.
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Affiliation(s)
- Fiona Low
- Department of Psychology, University at Albany, State University of New York, Albany, NY, USA
| | - Mitch Earleywine
- Department of Psychology, University at Albany, State University of New York, Albany, NY, USA
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van Elk M, Fried EI. History repeating: guidelines to address common problems in psychedelic science. Ther Adv Psychopharmacol 2023; 13:20451253231198466. [PMID: 37766730 PMCID: PMC10521293 DOI: 10.1177/20451253231198466] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 08/11/2023] [Indexed: 09/29/2023] Open
Abstract
Research in the last decade has expressed considerable optimism about the clinical potential of psychedelics for the treatment of mental disorders. This optimism is reflected in an increase in research papers, investments by pharmaceutical companies, patents, media coverage, as well as political and legislative changes. However, psychedelic science is facing serious challenges that threaten the validity of core findings and raise doubt regarding clinical efficacy and safety. In this paper, we introduce the 10 most pressing challenges, grouped into easy, moderate, and hard problems. We show how these problems threaten internal validity (treatment effects are due to factors unrelated to the treatment), external validity (lack of generalizability), construct validity (unclear working mechanism), or statistical conclusion validity (conclusions do not follow from the data and methods). These problems tend to co-occur in psychedelic studies, limiting conclusions that can be drawn about the safety and efficacy of psychedelic therapy. We provide a roadmap for tackling these challenges and share a checklist that researchers, journalists, funders, policymakers, and other stakeholders can use to assess the quality of psychedelic science. Addressing today's problems is necessary to find out whether the optimism regarding the therapeutic potential of psychedelics has been warranted and to avoid history repeating itself.
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Affiliation(s)
- Michiel van Elk
- Cognitive Psychology Unit, Institute of Psychology, Leiden University, PO Box 9555, Leiden 2300 RB, The Netherlands
| | - Eiko I. Fried
- Clinical Psychology Unit, Institute of Psychology, Leiden University, Leiden, The Netherlands
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Wall MB, Harding R, Zafar R, Rabiner EA, Nutt DJ, Erritzoe D. Neuroimaging in psychedelic drug development: past, present, and future. Mol Psychiatry 2023; 28:3573-3580. [PMID: 37759038 PMCID: PMC10730398 DOI: 10.1038/s41380-023-02271-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Accepted: 09/13/2023] [Indexed: 09/29/2023]
Abstract
Psychedelic therapy (PT) is an emerging paradigm with great transdiagnostic potential for treating psychiatric disorders, including depression, addiction, post-traumatic stress disorder, and potentially others. 'Classic' serotonergic psychedelics, such as psilocybin and lysergic acid diethylamide (LSD), which have a key locus of action at the 5-HT2A receptor, form the main focus of this movement, but substances including ketamine, 3,4-Methylenedioxymethamphetamine (MDMA) and ibogaine also hold promise. The modern phase of development of these treatment modalities in the early 21st century has occurred concurrently with the wider use of advanced human neuroscientific research methods; principally neuroimaging. This can potentially enable assessment of drug and therapy brain effects with greater precision and quantification than any previous novel development in psychiatric pharmacology. We outline the major trends in existing data and suggest the modern development of PT has benefitted greatly from the use of neuroimaging. Important gaps in existing knowledge are identified, namely: the relationship between acute drug effects and longer-term (clinically-relevant) effects, the precise characterisation of effects at the 5-HT2A receptor and relationships with functional/clinical effects, and the possible impact of these compounds on neuroplasticity. A road-map for future research is laid out, outlining clinical studies which will directly address these three questions, principally using combined Positron Emission Tomography (PET) and Magnetic Resonance Imaging (MRI) methods, plus other adjunct techniques. Multimodal (PET/MRI) studies using modern PET techniques such as the 5-HT2A-selective ligand [11 C]Cimbi-36 (and other ligands sensitive to neuroplasticity changes) alongside MRI measures of brain function would provide a 'molecular-functional-clinical bridge' in understanding. Such results would help to resolve some of these questions and provide a firmer foundation for the ongoing development of PT.
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Affiliation(s)
- Matthew B Wall
- Invicro, London, UK.
- Faculty of Medicine, Imperial College London, London, UK.
- Centre for Psychedelic research and Neuropsychopharmacology, Imperial College London, London, UK.
| | - Rebecca Harding
- Clinical Psychopharmacology Unit, Faculty of Brain Sciences, University College London, London, UK
| | - Rayyan Zafar
- Faculty of Medicine, Imperial College London, London, UK
- Centre for Psychedelic research and Neuropsychopharmacology, Imperial College London, London, UK
| | | | - David J Nutt
- Faculty of Medicine, Imperial College London, London, UK
- Centre for Psychedelic research and Neuropsychopharmacology, Imperial College London, London, UK
| | - David Erritzoe
- Faculty of Medicine, Imperial College London, London, UK
- Centre for Psychedelic research and Neuropsychopharmacology, Imperial College London, London, UK
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Öngür D. JAMA Psychiatry-The Year in Review, 2022. JAMA Psychiatry 2023; 80:413-414. [PMID: 36947053 DOI: 10.1001/jamapsychiatry.2023.0168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Affiliation(s)
- Dost Öngür
- Editor, JAMA Psychiatry
- McLean Hospital, Harvard Medical School, Belmont, Massachusetts
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Affiliation(s)
- Wayne D Hall
- The National Centre for Youth Substance Use Research, The University of Queensland, Brisbane, Australia
| | - Keith Humphreys
- Psychiatry and Behavioral Sciences, Stanford University, Palo Alto, California, USA
- Veterans Affairs Palo Alto Health Care System, Palo Alto, California, USA
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