Psilocybin-assisted mindfulness training modulates self-consciousness and brain default mode network connectivity with lasting effects

Incremental efficacy systematic review and meta-analysis of psilocybin-for-depression RCTs

RATIONALE

Psilocybin is a potentially paradigm-shifting depression intervention. We conducted a systematic review and meta-analysis of psilocybin-for-depression randomized controlled trials (RCTs).

OBJECTIVES

Systematically assess harm reporting, risk of bias, action mechanism specification, and incremental therapeutic effect sizes in the psilocybin-for-depression RCT literature.

METHODS

Assessed databases included PsycINFO, CINAHL, Embase, Medline, Web of Science, and Scopus. Search terms "Psilocybin" or "Psychedelic" were paired with "Depression", and "Randomized Controlled Trial" or "RCT".

RESULTS

We identified k = 9 RCTs (k = 10 subgroups) involving n = 602 participants (56% psilocybin). Five studies had low/very low harm quality reporting, opposed to two with high. Most studies demonstrated a high risk of bias. Therapeutic mechanisms of action (MoAs) were discussed in varying detail but rarely assessed in original publications. Psilocybin was moderately superior to controls at reducing depression (g = 0.62; 95% CI = 0.27, 0.98). Effects were heterogenous (τ = .47). Smaller studies evidenced stronger effects that favored psilocybin (Egger's b0 = 3.63, p = .014). Almost all studies documented financial conflicts of interests.

CONCLUSION

Psilocybin demonstrates significant depression reduction relative to controls. However, researchers, clinicians, and stakeholders should consider several contextual factors. Effects were moderate and attenuated in larger and better-controlled studies. Harms reporting and risk of bias was high, though partly driven by unique challenges of psilocybin research. MoAs were variably specified but rarely assessed; suggesting it is unclear how depression is reduced. We advise researchers conduct RCTs with active control conditions, larger samples, and include MoA assessments. Independent RCTs from researchers without financial conflicts of interest are needed.

Embracing change: impermanence acceptance mediates differences in death processing between long-term ayahuasca users and non-users

RATIONALE

The human psyche's interaction with death fundamentally shapes cognition, emotions, and behavior in both individuals and society. Death-related psychological phenomena have been shown to be influenced by psychedelic interventions. However, the literature lacks a comprehensive assessment of death-related processes in non-clinical settings, the mechanisms underlying long-term changes, and particularly the effects of ayahuasca on these dimensions.

OBJECTIVES

This cross-sectional study investigates death processing, potential mechanisms of change, and their predictors in ayahuasca veterans (N = 54) compared to non-users (N = 53).

METHODS

A battery of questionnaires and behavioral assessments were used to evaluate different aspects of death processing in both ayahuasca veterans and non-users. These assessments measured death fear and anxiety, death-acceptance, death-avoidant behaviors, and the accessibility of death-related thoughts. Mediators tested included personality traits, beliefs about the afterlife, trait mindfulness, and the concept of impermanence.

RESULTS

The findings demonstrated lower levels of death anxiety, avoidant behavior, and fear of death, as well as greater death acceptance in ayahuasca veterans. Mediation analyses revealed that group differences were not due to demographics, personality, trait mindfulness, ontological beliefs, or impermanence awareness, but rather to impermanence acceptance. Finally, within the ayahuasca group, lifetime ego dissolution experiences predicted the degree of impermanence acceptance.

CONCLUSIONS

These findings reveal significant, multi-dimensional differences in death processing between ayahuasca and non-psychedelic users. Impermanence acceptance emerged as the key mechanism of change. Additionally, the results highlight the role of acute ayahuasca experiences in producing lasting effects. Future interventions may focus on promoting impermanence acceptance as a strategy for managing existential fear.

Neural mechanisms of psychedelic visual imagery

Visual alterations under classic psychedelics can include rich phenomenological accounts of eyes-closed imagery. Preclinical evidence suggests agonism of the 5-HT2A receptor may reduce synaptic gain to produce psychedelic-induced imagery. However, this has not been investigated in humans. To infer the directed connectivity changes to visual connectivity underlying psychedelic visual imagery in healthy adults, a double-blind, randomised, placebo-controlled, cross-over study was performed, and dynamic causal modelling was applied to the resting state eyes-closed functional MRI scans of 24 subjects after administration of 0.2 mg/kg of the serotonergic psychedelic drug, psilocybin (magic mushrooms), or placebo. The effective connectivity model included the early visual area, fusiform gyrus, intraparietal sulcus, and inferior frontal gyrus. We observed a pattern of increased self-inhibition of both early visual and higher visual-association regions under psilocybin that was consistent with preclinical findings. We also observed a pattern of reduced inhibition from visual-association regions to earlier visual areas that indicated top-down connectivity is enhanced during visual imagery. The results were analysed with behavioural measures taken immediately after the scans, suggesting psilocybin-induced decreased sensitivity to neural inputs is associated with the perception of eyes-closed visual imagery. The findings inform our basic and clinical understanding of visual perception. They reveal neural mechanisms that, by affecting balance, may increase the impact of top-down feedback connectivity on perception, which could contribute to the visual imagery seen with eyes-closed during psychedelic experiences.

Psychedelics and Suicide-Related Outcomes: A Systematic Review

Background/Objectives: Suicide accounts for 1.4% of global deaths, and the slow-acting nature of traditional treatments for suicide risk underscores the need for alternatives. Psychedelic therapies may rapidly reduce suicide risk. This systematic review evaluates impact of psychedelic therapies on suicide-related outcomes. Methods: A systematic search of MEDLINE, Embase, PsycINFO, and ClinicalTrials.gov was conducted up to November 2024. Results: Four randomized controlled trials (RCTs) evaluated suicidality as a secondary outcome or safety measure, showing significant reductions in suicidal ideation with psilocybin (three studies) and MDMA-assisted therapy (MDMA-AT; one study). Effect sizes, measured by Cohen's d, ranged from =0.52 to 1.25 (p = 0.01 to 0.005), with no safety issues reported. Five additional RCTs assessed suicidality as a safety measure, showing reductions in suicidal ideation with psilocybin (two studies) and MDMA-AT (three studies; p = 0.02 to 0.04). Among 24 non-randomized and cross-sectional studies, results were mixed. Psilocybin (three studies) reduced suicidal ideation, with odds ratios (OR) of 0.40-0.75. MDMA-AT (five studies in PTSD patients) had a pooled effect size of d = 0.61 (95% CI: 0.32-0.89). LSD (six studies) showed increased odds of suicidality, with odds ratios ranging from 1.15 to 2.08. Studies involving DMT (two studies) and multiple psychedelics (three studies) showed mixed results, with DMT studies not showing significant effects on suicidality and studies involving multiple psychedelics showing varying outcomes, some reporting reductions in suicidal ideation and others showing no significant change. Conclusions: The effect of psychedelic therapies on suicide-related outcomes remains inconclusive, highlighting the need for further trials to clarify safety and therapeutic mechanisms.

On the varieties of conscious experiences: Altered Beliefs Under Psychedelics (ALBUS)

How is it that psychedelics so profoundly impact brain and mind? According to the model of "Relaxed Beliefs Under Psychedelics" (REBUS), 5-HT2a agonism is thought to help relax prior expectations, thus making room for new perspectives and patterns. Here, we introduce an alternative (but largely compatible) perspective, proposing that REBUS effects may primarily correspond to a particular (but potentially pivotal) regime of very high levels of 5-HT2a receptor agonism. Depending on both a variety of contextual factors and the specific neural systems being considered, we suggest opposite effects may also occur in which synchronous neural activity becomes more powerful, with accompanying "Strengthened Beliefs Under Psychedelics" (SEBUS) effects. Such SEBUS effects are consistent with the enhanced meaning-making observed in psychedelic therapy (e.g. psychological insight and the noetic quality of mystical experiences), with the imposition of prior expectations on perception (e.g. hallucinations and pareidolia), and with the delusional thinking that sometimes occurs during psychedelic experiences (e.g. apophenia, paranoia, engendering of inaccurate interpretations of events, and potentially false memories). With "Altered Beliefs Under Psychedelics" (ALBUS), we propose that the manifestation of SEBUS vs. REBUS effects may vary across the dose-response curve of 5-HT2a signaling. While we explore a diverse range of sometimes complex models, our basic idea is fundamentally simple: psychedelic experiences can be understood as kinds of waking dream states of varying degrees of lucidity, with similar underlying mechanisms. We further demonstrate the utility of ALBUS by providing neurophenomenological models of psychedelics focusing on mechanisms of conscious perceptual synthesis, dreaming, and episodic memory and mental simulation.

Can psychedelic use benefit meditation practice? Examining individual, psychedelic, and meditation-related factors

INTRODUCTION

Meditation practice and psychedelic use have attracted increasing attention in the public sphere and scientific research. Both methods induce non-ordinary states of consciousness that may have significant therapeutic benefits. Thus, there is growing scientific interest in potential synergies between psychedelic use and meditation practice with some research suggesting that psychedelics may benefit meditation practice. The present study examined individual, psychedelic-related, and meditation-related factors to determine under what conditions meditators perceive psychedelic use as beneficial for their meditation practice.

METHOD

Participants (N = 863) who had reported psychedelic use and a regular meditation practice (at least 3 times per week during the last 12 months) were included in the study. To accommodate a large number of variables, machine learning (i.e., elastic net, random forest) was used to analyze the data.

RESULTS

Most participants (n = 634, 73.5%) found psychedelic use to have a positive influence on their quality of meditation. Twenty-eight variables showed significant zero-order associations with perceived benefits even following a correction. Elastic net had the best performance (R2 = .266) and was used to identify the most important features. Across 53 variables, the model found that greater use of psychedelics, intention setting during psychedelic use, agreeableness, and exposure to N,N-Dimethyltryptamine (N,N-DMT) were most likely to be associated with the perception that psychedelics benefit meditation practice. The results were consistent across several different approaches used to identify the most important variables (i.e., Shapley values, feature ablation).

DISCUSSION

Results suggest that most meditators found psychedelic use to have a positive influence on their meditation practice, with: 1) regularity of psychedelic use, 2) the setting of intentions for psychedelic use, 3) having an agreeable personality, and 4) reported use of N,N-DMT being the most likely predictors of perceiving psychedelic use as beneficial. Longitudinal designs and randomized trials manipulating psychedelic use are needed to establish causality.

[Neuroimaging correlates of classical psychedelics effects: A systematic review]

BACKGROUND

Current scientific literature supports classical psychedelic efficacy in many psychiatric disorders. However, less attention has been given to the neurological effects of these substances. The aim of this medical thesis was to conduct a systematic review examining the neuroimaging correlates of the effects of psychedelics.

METHOD

We performed an electronic research through Medline and Science Direct databases. A comprehensive search yielded 460 articles published up to May 2022. After a cautious screening process, we selected 49 scientific papers for further analysis.

RESULTS

Major findings included reduced functional network integration, increased between-network functional connectivity, and expansion of functional connectivity patterns repertoire under psychedelics. Thalamic gating and emotional processing were also impaired. These results positively correlated with symptom improvement in pathological populations.

CONCLUSION

To this day, our knowledge concerning psychedelic effects remains partial. Several neurocognitive theories have been developed in recent years to model psychedelic phenomenology, but no unifying theory has emerged. Studies involving larger populations investigating various psychiatric disorders, including several neuroimaging modalities and considering medium- and long-term effects, would be necessary to deepen current knowledge.

Catalyst for change: Psilocybin's antidepressant mechanisms-A systematic review

BACKGROUND

Recent clinical trials suggest promising antidepressant effects of psilocybin, despite methodological challenges. While various studies have investigated distinct mechanisms and proposed theoretical opinions, a comprehensive understanding of psilocybin's neurobiological and psychological antidepressant mechanisms is lacking.

AIMS

Systematically review potential antidepressant neurobiological and psychological mechanisms of psilocybin.

METHODS

Search terms were generated based on existing evidence of psilocybin's effects related to antidepressant mechanisms. Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines, 15 studies were systematically reviewed, exploring various therapeutic change principles such as brain dynamics, emotion regulation, cognition, self-referential processing, connectedness, and interpersonal functioning.

RESULTS

Within a supportive setting, psilocybin promoted openness, cognitive and neural flexibility, and greater ability and acceptance of emotional experiences. A renewed sense of connectedness to the self, others, and the world emerged as a key experience. Imaging studies consistently found altered brain dynamics, characterized by reduced global and within default mode network connectivity, alongside increased between-network connectivity.

CONCLUSIONS

Together, these changes may create a fertile yet vulnerable window for change, emphasizing the importance of a supportive set, setting, and therapeutic guidance. The results suggest that psilocybin, within a supportive context, may induce antidepressant effects by leveraging the interplay between neurobiological mechanisms and common psychotherapeutic factors. This complements the view of purely pharmacological effects, supporting a multileveled approach that reflects various relevant dimensions of therapeutic change, including neurobiological, psychological, and environmental factors.

Clinical and preclinical evidence of psilocybin as antidepressant. A narrative review

In the rapidly growing field of psychedelic research, psilocybin (and active metabolite psilocin) has been proposed as a promising candidate in the search for novel treatments for neuropsychiatric disorders. Clinical trials have revealed that psilocybin has a large, rapid, and persistent effect in the improvement of symptoms of depression and anxiety. The safety profile is considered favourable, with low toxicity and good tolerance. Several preclinical studies have also been carried out to determine the long-term mechanism of action of this drug. In this sense, preclinical studies in naïve animals as well as in animal models of disease have shown somewhat discrepant results in conventional tests for assessment of depression- and anxiety-like phenotype in response to psilocybin, but overall suggest positive outcomes. Additionally, several valuable assays in rodent models have been developed over the years to elucidate the neurochemical correlates of serotonin 2A receptor (5HT2AR) activation in the brain, primary molecular target of psilocin. This review aims to provide a general overview of the current and most recent literature in the therapeutic potential of psilocybin through a description of clinical trials of psilocybin-assisted psychotherapy, and to showcase the scene in the up-to-date preclinical research. A detailed description of preclinical rodent models and experimental approaches that have been used to study the neurobiological and behavioural actions of psilocybin is provided, and potential therapeutic mechanisms of action are discussed.

Psilocybin-Assisted Group Psychotherapy + Mindfulness Based Stress Reduction (MBSR) for Frontline Healthcare Provider COVID-19 Related Depression and Burnout: A Randomized Clinical Trial

Objective

This clinical trial sought to evaluate the safety and preliminary efficacy of psilocybin and MBSR for frontline healthcare providers with symptoms of depression and burnout related to the COVID-19 pandemic.

Methods

This was a randomized controlled trial that enrolled physicians and nurses with frontline clinical work during the COVID-19 pandemic and symptoms of depression and burnout. Participants were randomized in a 1:1 ratio to either an 8-week MBSR curriculum alone or an 8-week MBSR curriculum plus group psilocybin-assisted psychotherapy (PAP) with 25mg psilocybin. Symptoms of depression and burnout were assessed at baseline, and 2-weeks and 6-months post intervention utilizing the Quick Inventory of Depressive Symptoms (QIDS-SR-16) and Maslach Burnout Inventory Human Services Survey for Medical Professionals (MBI-HSS-MP), respectively. Secondary outcome measures included the Demoralization Scale (DS-II) and the Watt's Connectedness Scale (WCS). Adverse events and suicidality were assessed through 6-month follow-up.

Results

25 participants were enrolled and randomized. There were 12 study-related AEs recorded that were Grade 1-2 and no serious AEs. There was larger decrease in QIDS score for the MBSR+PAP arm compared to MBSR-only from baseline to 2-weeks post-intervention and significant between-group differences favoring MBSR+PAP on subscales of the MBI-HSS-MP as well as the DS-II and WCS.

Conclusions

Group psilocybin-assisted therapy plus MBSR was associated with clinically significant improvement in depressive symptoms without serious adverse events and with greater reduction in symptoms than MBSR alone. Study findings suggest that integrating psilocybin with mindfulness training may represent a promising treatment for depression and burnout among physicians and nurses.

Synergistic, multi-level understanding of psychedelics: three systematic reviews and meta-analyses of their pharmacology, neuroimaging and phenomenology

Serotonergic psychedelics induce altered states of consciousness and have shown potential for treating a variety of neuropsychiatric disorders, including depression and addiction. Yet their modes of action are not fully understood. Here, we provide a novel, synergistic understanding of psychedelics arising from systematic reviews and meta-analyses of three hierarchical levels of analysis: (1) subjective experience (phenomenology), (2) neuroimaging and (3) molecular pharmacology. Phenomenologically, medium and high doses of LSD yield significantly higher ratings of visionary restructuralisation than psilocybin on the 5-dimensional Altered States of Consciousness Scale. Our neuroimaging results reveal that, in general, psychedelics significantly strengthen between-network functional connectivity (FC) while significantly diminishing within-network FC. Pharmacologically, LSD induces significantly more inositol phosphate formation at the 5-HT2A receptor than DMT and psilocin, yet there are no significant between-drug differences in the selectivity of psychedelics for the 5-HT2A, 5-HT2C, or D2 receptors, relative to the 5-HT1A receptor. Our meta-analyses link DMT, LSD, and psilocybin to specific neural fingerprints at each level of analysis. The results show a highly non-linear relationship between these fingerprints. Overall, our analysis highlighted the high heterogeneity and risk of bias in the literature. This suggests an urgent need for standardising experimental procedures and analysis techniques, as well as for more research on the emergence between different levels of psychedelic effects.

The revival of psilocybin between scientific excitement, evidence of efficacy, and real-world challenges

The revival of psilocybin in psychopharmacological research heralds a potential paradigm shift for treating mood and anxiety disorders, and other psychiatric conditions beyond the psychotic spectrum. This critical review evaluates current evidence on psilocybin's efficacy, juxtaposing potential benefits with the practical aspects of psychedelic-assisted psychotherapy (PAP) and the methodological constraints of existing research.An electronic literature search was conducted using PubMed/MEDLINE, selecting studies published up to December 2023 that explored the clinical use of psilocybin in mood and anxiety disorders, obsessive-compulsive disorder, post-traumatic stress disorder, and substance use disorder. Despite promising preliminary results suggesting psilocybin's efficacy in alleviating depression and anxiety, as well as obsessions, compulsions, and addictive behaviors, significant evidence gaps persist. These include evaluating the efficacy of psilocybin compared to standard antidepressants or anxiolytic molecules and identifying patient subpopulations that might benefit most from PAP. Concerns about psilocybin's safety, long-term efficacy, and optimal dosage remain unclear due to previous trials' limitations. Real-world implementation faces challenges, including infrastructural requirements, personnel training, and unresolved legal and ethical issues. This paper argues for further research to substantiate the evidence base, emphasizing the need for larger studies that overcome current methodological limitations and explore psilocybin's full therapeutic potential. While psilocybin holds promise for psychiatry, its successful translation from research to clinical practice demands more robust evidence on efficacy, safety, and methodological rigor. In addition, other factors, such as cultural stigma and legal/ethical issues, need to be successfully addressed to facilitate psilocybin's implementation in healthcare systems.

Neuromodulation and meditation: A review and synthesis toward promoting well-being and understanding consciousness and brain

The neuroscience of meditation is providing insight into meditation's beneficial effects on well-being and informing understanding of consciousness. However, further research is needed to explicate mechanisms linking brain activity and meditation. Non-invasive brain stimulation (NIBS) presents a promising approach for causally investigating neural mechanisms of meditation. Prior NIBS-meditation research has predominantly targeted frontal and parietal cortices suggesting that it might be possible to boost the behavioral and neural effects of meditation with NIBS. Moreover, NIBS has revealed distinct neural signatures in long-term meditators. Nonetheless, methodological variations in NIBS-meditation research contributes to challenges for definitive interpretation of previous results. Future NIBS studies should further investigate core substrates of meditation, including specific brain networks and oscillations, and causal neural mechanisms of advanced meditation. Overall, NIBS-meditation research holds promise for enhancing meditation-based interventions in support of well-being and resilience in both non-clinical and clinical populations, and for uncovering the brain-mind mechanisms of meditation and consciousness.

Exploring neural markers of dereification in meditation based on EEG and personalized models of electrophysiological brain states

With mounting evidence for the benefits of meditation, there has been a growing interest in measuring and quantifying meditative states. This study introduces the Inner Dereification Index (IDI), a class of personalized models designed to quantify the distance from non-meditative states such as mind wandering based on a single individual's neural activity. In addition to demonstrating high classification accuracy (median AUC: 0.996) at distinguishing meditation from thinking states moment by moment, IDI can accurately stratify meditator cohorts by experience, and correctly identify the practices most effective at training the dereification aspect of meditation (decentering from immersion with thoughts and perceptions and recognizing them as mental constructs). These results suggest that IDI models may be a useful real-time proxy for dereification and meditation progress, requiring only 1 min of mind wandering data (and no meditation data) during model training. Thus, they show promise for applications such as real-time meditation feedback, progress tracking, personalization of practices, and potential therapeutic applications of neurofeedback-assisted generation of positive states of consciousness.

Meditating on psychedelics. A randomized placebo-controlled study of DMT and harmine in a mindfulness retreat

BACKGROUND

In recent years, both meditation and psychedelics have attracted rapidly increasing scientific interest. While the current state of evidence suggests the promising potential of psychedelics, such as psilocybin, to enhance meditative training, it remains equivocal whether these effects are specifically bound to psilocybin or if other classical psychedelics might show synergistic effects with meditation practice. One particularly promising candidate is N,N-dimethyltryptamine (DMT), an active ingredient of ayahuasca.

AIM

This study aims to investigate the effect of the psychedelic substance DMT, combined with the monoamine oxidase inhibitor harmine (DMT-harmine), on meditative states, compared to meditation with a placebo.

METHOD

Forty experienced meditators (18 females and 22 males) participated in a double-blind, placebo-controlled study over a 3-day meditation retreat, receiving either placebo or DMT-harmine. Participants' levels of mindfulness, compassion, insight, and transcendence were assessed before, during, and after the meditation group retreat, using psychometric questionnaires.

RESULTS

Compared to meditation with a placebo, meditators who received DMT and harmine self-attributed greater levels of mystical-type experiences, non-dual awareness, and emotional breakthrough during the acute substance effects and, when corrected for baseline differences, greater psychological insight 1 day later. Mindfulness and compassion were not significantly different in the DMT-harmine group compared to placebo. At 1-month follow-up, the meditators who received DMT and harmine rated their experience as significantly more personally meaningful, spiritually significant, and well-being-enhancing than the meditators who received placebo.

CONCLUSION

Investigating the impact of DMT-harmine on meditators in a naturalistic mindfulness group retreat, this placebo-controlled study highlights the specific effects of psychedelics during meditation.

TRIAL REGISTRATION

ClinicalTrials.gov identifier NCT05780216.

Mind over matter: the microbial mindscapes of psychedelics and the gut-brain axis

Psychedelics have emerged as promising therapeutics for several psychiatric disorders. Hypotheses around their mechanisms have revolved around their partial agonism at the serotonin 2 A receptor, leading to enhanced neuroplasticity and brain connectivity changes that underlie positive mindset shifts. However, these accounts fail to recognise that the gut microbiota, acting via the gut-brain axis, may also have a role in mediating the positive effects of psychedelics on behaviour. In this review, we present existing evidence that the composition of the gut microbiota may be responsive to psychedelic drugs, and in turn, that the effect of psychedelics could be modulated by microbial metabolism. We discuss various alternative mechanistic models and emphasize the importance of incorporating hypotheses that address the contributions of the microbiome in future research. Awareness of the microbial contribution to psychedelic action has the potential to significantly shape clinical practice, for example, by allowing personalised psychedelic therapies based on the heterogeneity of the gut microbiota.

Perspectives and preliminary experiences of psychedelics for the treatment of eating disorders: A systematic scoping review

OBJECTIVE

Research regarding the therapeutic application of psychedelics and psychedelic-assisted psychotherapy in the treatment of eating disorders (EDs) has begun to emerge. This systematic scoping review aimed to map and synthesise the existing evidence regarding the participant reported efficacy and perspectives concerning psychedelics in the treatment of EDs, and to identify significant research gaps.

METHOD

A systematic search was undertaken across several databases in accordance with Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews guidelines.

RESULTS

1290 publications were identified, 1135 after duplicates removed, with 17 meeting full-eligibility criteria. Overall, findings suggested that most participants reported experiencing a meaningful reduction in their ED symptoms and having positive experiences or an openness to explore psychedelics as a treatment for ED symptoms, although some noted concerns of adverse effects and the importance of having psychological support to increase safety and efficacy.

CONCLUSIONS

While preliminary research suggests psychedelics and psychedelic-assisted psychotherapy may be a viable treatment option for ED symptoms, further research with more robust research designs is required to increase confidence in its efficacy, generalisability, and safety as a therapeutic medium.

Can Psychedelic Use Benefit Meditation Practice? Examining Individual, Psychedelic, and Meditation-Related Factors

Introduction

Meditation practice and psychedelic use have attracted increasing attention in the public sphere and scientific research. Both methods induce non-ordinary states of consciousness that may have significant therapeutic benefits. Thus, there is growing scientific interest in potential synergies between psychedelic use and meditation practice with some research suggesting that psychedelics may benefit meditation practice. The present study examined individual, psychedelic-related, and meditation-related factors to determine under what conditions meditators perceive psychedelic use as beneficial for their meditation practice.

Method

Participants (N = 863) who had reported psychedelic use and a regular meditation practice (at least 3 times per week during the last 12 months) were included in the study. To accommodate a large number of variables, machine learning (i.e., elastic net, random forest) was used to analyze the data.

Results

Most participants (n = 634, 73.5%) found psychedelic use to have a positive influence on their quality of meditation. Twenty-eight variables showed significant zero-order associations with perceived benefits even following a correction. Elastic net had the best performance (R2 = .266) and was used to identify the most important features. Across 53 variables, the model found that greater use of psychedelics, intention setting during psychedelic use, agreeableness, and exposure to N,N-Dimethyltryptamine (N,N-DMT) were most likely to be associated with the perception that psychedelics benefit meditation practice. The results were consistent across several different approaches used to identify the most important variables (i.e., Shapley values, feature ablation).

Discussion

Results suggest that most meditators found psychedelic use to have a positive influence on their meditation practice, with: 1) regularity of psychedelic use, 2) the setting of intentions for psychedelic use, 3) having an agreeable personality, and 4) reported use of N,N-DMT being the most likely predictors of perceiving psychedelic use as beneficial. Longitudinal designs and randomized trials manipulating psychedelic use are needed to establish causality.

Psilocybin for the treatment of Alzheimer's disease

Alzheimer's disease (AD) stands as a formidable neurodegenerative ailment and a prominent contributor to dementia. The scarcity of available therapies for AD accentuates the exigency for innovative treatment modalities. Psilocybin, a psychoactive alkaloid intrinsic to hallucinogenic mushrooms, has garnered attention within the neuropsychiatric realm due to its established safety and efficacy in treating depression. Nonetheless, its potential as a therapeutic avenue for AD remains largely uncharted. This comprehensive review endeavors to encapsulate the pharmacological effects of psilocybin while elucidating the existing evidence concerning its potential mechanisms contributing to a positive impact on AD. Specifically, the active metabolite of psilocybin, psilocin, elicits its effects through the modulation of the 5-hydroxytryptamine 2A receptor (5-HT2A receptor). This modulation causes heightened neural plasticity, diminished inflammation, and improvements in cognitive functions such as creativity, cognitive flexibility, and emotional facial recognition. Noteworthy is psilocybin's promising role in mitigating anxiety and depression symptoms in AD patients. Acknowledging the attendant adverse reactions, we proffer strategies aimed at tempering or mitigating its hallucinogenic effects. Moreover, we broach the ethical and legal dimensions inherent in psilocybin's exploration for AD treatment. By traversing these avenues, We propose therapeutic potential of psilocybin in the nuanced management of Alzheimer's disease.

The effects of psilocybin on cognition and emotional processing in healthy adults and adults with depression: a systematic literature review

INTRODUCTION

Psilocybin, a naturally occurring serotonergic agonist in some mushroom species, has shown promise as a novel, fast-acting pharmacotherapy seeking to overcome the limitations of conventional first-line antidepressants. Studying psilocybin effects on cognition and emotional processing may help to clarify the mechanisms underlying the therapeutic potential of psilocybin and may also support studies with people suffering from depression. Thus, this review aims to provide a comprehensive overview of the current literature regarding the effects of psilocybin on these two key areas in both healthy and depressed populations.

METHOD

A systematic search was performed on 29 January 2024, in the PubMed, EBSCOhost, Web of Science and SCOPUS databases. After duplicates removal, study selection was conducted considering pre-specified criteria. Data extraction was then performed. The quality assessment of the studies was carried out using the Cochrane Collaboration tools for randomized (RoB 2.0) and non-randomized (ROBINS-I) controlled trials.

RESULTS

Twenty articles were included, with 18 targeting healthy adults and two adults with depression. Results point to impairments within attentional and inhibitory processes, and improvements in the domains of creativity and social cognition in healthy individuals. In the population with depression, only cognitive flexibility and emotional recognition were affected, both being enhanced. The comparison of outcomes from both populations proved limited.

CONCLUSIONS

Psilocybin acutely alters several cognitive domains, with a localized rather than global focus, in a dose- and time-dependent manner. However, the significant methodological constraints call for further research, in the context of depression and with standardized protocols, with longitudinal studies also imperative.

Dynamic Functional Hyperconnectivity After Psilocybin Intake Is Primarily Associated With Oceanic Boundlessness

BACKGROUND

Psilocybin is a widely studied psychedelic substance that 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 undercharacterized because 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 6 minutes in an eyes-open resting state during the peak subjective drug effect (102 minutes posttreatment) in ultrahigh field 7T magnetic resonance imaging. The 5-Dimensional Altered States of Consciousness Rating Scale was administered 360 minutes after drug intake.

RESULTS

Under psilocybin, there were alterations across all dimensions of the 5-Dimensional Altered States of Consciousness Rating Scale and widespread increases in averaged brain functional connectivity. Time-varying functional connectivity analysis unveiled a recurrent hyperconnected pattern characterized by low blood oxygen level-dependent signal amplitude, suggesting heightened cortical arousal. In terms of neuroexperiential 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 at both the brain and the experiential levels. 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, thereby providing insights into the neurophysiology and neuroexperiential qualities of the psychedelic state.

Psychedelics in developmental stuttering to modulate brain functioning: a new therapeutic perspective?

Developmental stuttering (DS) is a neurodevelopmental speech-motor disorder characterized by symptoms such as blocks, repetitions, and prolongations. Persistent DS often has a significant negative impact on quality of life, and interventions for it have limited efficacy. Herein, we briefly review existing research on the neurophysiological underpinnings of DS -specifically, brain metabolic and default mode/social-cognitive networks (DMN/SCN) anomalies- arguing that psychedelic compounds might be considered and investigated (e.g., in randomized clinical trials) for treatment of DS. The neural background of DS is likely to be heterogeneous, and some contribution from genetically determinants of metabolic deficiencies in the basal ganglia and speech-motor cortical regions are thought to play a role in appearance of DS symptoms, which possibly results in a cascade of events contributing to impairments in speech-motor execution. In persistent DS, the difficulties of speech are often linked to a series of associated aspects such as social anxiety and social avoidance. In this context, the SCN and DMN (also influencing a series of fronto-parietal, somato-motor, and attentional networks) may have a role in worsening dysfluencies. Interestingly, brain metabolism and SCN/DMN connectivity can be modified by psychedelics, which have been shown to improve clinical evidence of some psychiatric conditions (e.g., depression, post-traumatic stress disorder, etc.) associated with psychological constructs such as rumination and social anxiety, which also tend to be present in persistent DS. To date, while there have been no controlled trials on the effects of psychedelics in DS, anecdotal evidence suggests that these agents may have beneficial effects on stuttering and its associated characteristics. We suggest that psychedelics warrant investigation in DS.

Psychedelics and disorders of consciousness: the current landscape and the path forward

Modern medicine has been shaken by the surge of psychedelic science that proposes a new approach to mitigate mental disorders, such as depression and post-traumatic stress disorder. Clinical trials to investigate whether psychedelic substances can treat psychiatric conditions are now underway, yet less discussion gravitates around their use in neurological disorders due to brain injury. One suggested implementation of brain-complexity enhancing psychedelics is to treat people with post-comatose disorders of consciousness (DoC). In this article, we discuss the rationale of this endeavour, examining possible outcomes of such experiments by postulating the existence of an optimal level of complexity. We consider the possible counterintuitive effects of both psychedelics and DoC on the functional connectivity of the default mode network and its possible impact on selfhood. We also elaborate on the role of computational modelling in providing complementary information to experimental studies, both contributing to our understanding of the treatment mechanisms and providing a path towards personalized medicine. Finally, we update the discourse surrounding the ethical considerations, encompassing clinical and scientific values.

Unlocking the healing power of psilocybin: an overview of the role of psilocybin therapy in major depressive disorder, obsessive-compulsive disorder and substance use disorder

Resistance to traditional treatment methods is still a major obstacle in modern psychiatry. As a result, several studies are currently being conducted to find effective alternatives to traditional therapies. One of these alternatives is psilocybin, a psychedelic substance that has been tested in clinical trials as an adjunct to psychotherapy. These studies focus on patients with major depressive disorder (MDD), obsessive-compulsive disorder (OCD) and substance use disorder (SUD), particularly alcohol and nicotine dependence. This article looks at the current understanding of psilocybin, including data from clinical trials conducted, psilocybin's mechanism of action, its safety and the level of risk associated with it.

Forgetting ourselves in flow: an active inference account of flow states and how we experience ourselves within them

Flow has been described as a state of optimal performance, experienced universally across a broad range of domains: from art to athletics, gaming to writing. However, its phenomenal characteristics can, at first glance, be puzzling. Firstly, individuals in flow supposedly report a loss of self-awareness, even though they perform in a manner which seems to evince their agency and skill. Secondly, flow states are felt to be effortless, despite the prerequisite complexity of the tasks that engender them. In this paper, we unpick these features of flow, as well as others, through the active inference framework, which posits that action and perception are forms of active Bayesian inference directed at sustained self-organisation; i.e., the minimisation of variational free energy. We propose that the phenomenology of flow is rooted in the deployment of high precision weight over (i) the expected sensory consequences of action and (ii) beliefs about how action will sequentially unfold. This computational mechanism thus draws the embodied cognitive system to minimise the ensuing (i.e., expected) free energy through the exploitation of the pragmatic affordances at hand. Furthermore, given the challenging dynamics the flow-inducing situation presents, attention must be wholly focussed on the unfolding task whilst counterfactual planning is restricted, leading to the attested loss of the sense of self-as-object. This involves the inhibition of both the sense of self as a temporally extended object and higher-order, meta-cognitive forms of self-conceptualisation. Nevertheless, we stress that self-awareness is not entirely lost in flow. Rather, it is pre-reflective and bodily. Our approach to bodily-action-centred phenomenology can be applied to similar facets of seemingly agentive experience beyond canonical flow states, providing insights into the mechanisms of so-called selfless experiences, embodied expertise and wellbeing.

Alterations in brain network connectivity and subjective experience induced by psychedelics: a scoping review

Intense interest surrounds current research on psychedelics, particularly regarding their potential in treating mental health disorders. Various studies suggest a link between the subjective effects produced by psychedelics and their therapeutic efficacy. Neuroimaging evidence indicates an association of changes in brain functional connectivity with the subjective effects of psychedelics. We conducted a review focusing on psychedelics and brain functional connectivity. The review focused on four psychedelic drugs: ayahuasca, psilocybin and LSD, and the entactogen MDMA. We conducted searches in databases of MEDLINE, Embase, APA PsycInfo and Scopus from inception to Jun 2023 by keywords related to functional connectivity and psychedelics. Using the PRISMA framework, we selected 24 articles from an initial pool of 492 for analysis. This scoping review and analysis investigated the effects of psychedelics on subjective experiences and brain functional connectivity in healthy individuals. The studies quantified subjective effects through psychometric scales, revealing significant experiences of altered consciousness, mood elevation, and mystical experiences induced by psychedelics. Neuroimaging results indicated alterations in the functional connectivity of psychedelics, with consistent findings across substances of decreased connectivity within the default mode network and increased sensory and thalamocortical connectivity. Correlations between these neurophysiological changes and subjective experiences were noted, suggesting a brain network basis of the psychedelics' neuropsychological impact. While the result of the review provides a potential neural mechanism of the subjective effects of psychedelics, direct clinical evidence is needed to advance their clinical outcomes. Our research serves as a foundation for further exploration of the therapeutic potential of psychedelics.

Comparing Neural Correlates of Consciousness: From Psychedelics to Hypnosis and Meditation

BACKGROUND

Pharmacological and nonpharmacological methods of inducing altered states of consciousness (ASCs) are becoming increasingly relevant in the treatment of psychiatric disorders. While comparisons between them are often drawn, to date no study has directly compared their neural correlates.

METHODS

To address this knowledge gap, we directly compared 2 pharmacological methods (psilocybin 0.2 mg/kg orally [n = 23] and lysergic acid diethylamide [LSD] 100 μg orally [n = 25]) and 2 nonpharmacological methods (hypnosis [n = 30] and meditation [n = 29]) using resting-state functional connectivity magnetic resonance imaging and assessed the predictive value of the data using a machine learning approach.

RESULTS

We found that 1) no network reached significance in all 4 ASC methods; 2) pharmacological and nonpharmacological interventions of inducing ASCs showed distinct connectivity patterns that were predictive at the individual level; 3) hypnosis and meditation showed differences in functional connectivity when compared directly and also drove distinct differences when jointly compared with the pharmacological ASC interventions; and 4) psilocybin and LSD showed no differences in functional connectivity when directly compared with each other, but they did show distinct behavioral-neural relationships.

CONCLUSIONS

Overall, these results extend our understanding of the mechanisms of action of ASCs and highlight the importance of exploring how these effects can be leveraged in the treatment of psychiatric disorders.

Chronic pain as an emergent property of a complex system and the potential roles of psychedelic therapies

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.

Unlocking the self: Can microdosing psychedelics make one feel more authentic?

Background and aim: In the present study, we focus on the relationship between state authenticity - the experience of being true to oneself in a particular moment - and microdosing - a practice that implies repeatedly ingesting very small doses of psychedelics that do not reach the threshold for perceptual alterations. We propose that microdosing could increase state authenticity through influencing people's mood and the number and satisfaction with daily activities. Methods: We used self-assessments of state authenticity collected from 18 microdosers in the Netherlands across the period of 1 month for a total of 192 observations. Results: We found that on the microdosing day and the day thereafter, state authenticity was significantly higher. Furthermore, the number of activities and the satisfaction with them were higher on the day when participants microdosed, while the following day only the number of activities was higher. Both the number or activities and the satisfaction with them were positively related to state authenticity. Conclusion: We propose that feeling and behaving authentically could have a central role in explaining the positive effects of microdosing on health and wellbeing that are reported by current research.

Acceptability of psilocybin-assisted group therapy in patients with cancer and major depressive disorder: Qualitative analysis

BACKGROUND

The present study explored the acceptability of psilocybin-assisted group therapy from the perspective of patients with cancer and depression who participated in a clinical trial assessing the safety and efficacy of this novel intervention.

METHODS

Guided by the conceptual framework of acceptability, the authors conducted semi-structured interviews with participants of the psilocybin trial. Data were analyzed using template and thematic analyses.

RESULTS

Participants' (n = 28) perspectives on the acceptability of the group and simultaneous sessions was generally positive, both in terms of safety and efficacy: first, the groups contributed to increase participants' sense of safety and preparedness as they were engaging in the therapy; and second, the groups fostered a sense of connection and of belonging, which served to enrich and deepen the meaning of participants' experience, ultimately opening a dimension of self-transcendence and compassion. Other subthemes related to factors influencing the acceptability of the group approach included: 1) the importance of the therapeutic framework, 2) the complementary value of individual sessions, 3) disruptive factors related to the group and/or simultaneous setting, and 4) opportunities and challenges related to group size and how to structure interactions.

CONCLUSIONS

This study enhances understanding of what promotes acceptability of the psilocybin-assisted therapy group model for the treatment of MDD in cancer patients.

PLAIN LANGUAGE SUMMARY

We conducted exit interviews with participants of a phase 2 trial of psilocybin-assisted therapy (PAT) conducted in a community cancer center, to assess the acceptability of a novel psilocybin delivery model combining simultaneous individual therapy and group sessions. Our findings support the acceptability of this intervention and suggest that in addition to being feasible, it might also enhance participants' perceived safety and efficacy compared to uniquely individual or group delivery models of PAT. Our analysis highlights critical factors conditioning acceptability and suggests new ways PAT may be scaled and integrated into cancer care.

The unique neural signature of your trip: Functional connectome fingerprints of subjective psilocybin experience

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.

Psilocybin enhances insightfulness in meditation: a perspective on the global topology of brain imaging during meditation

In this study, for the first time, we explored a dataset of functional magnetic resonance images collected during focused attention and open monitoring meditation before and after a five-day psilocybin-assisted meditation retreat using a recently established approach, based on the Mapper algorithm from topological data analysis. After generating subject-specific maps for two groups (psilocybin vs. placebo, 18 subjects/group) of experienced meditators, organizational principles were uncovered using graph topological tools, including the optimal transport (OT) distance, a geometrically rich measure of similarity between brain activity patterns. This revealed characteristics of the topology (i.e. shape) in space (i.e. abstract space of voxels) and time dimension of whole-brain activity patterns during different styles of meditation and psilocybin-induced alterations. Most interestingly, we found that (psilocybin-induced) positive derealization, which fosters insightfulness specifically when accompanied by enhanced open-monitoring meditation, was linked to the OT distance between open-monitoring and resting state. Our findings suggest that enhanced meta-awareness through meditation practice in experienced meditators combined with potential psilocybin-induced positive alterations in perception mediate insightfulness. Together, these findings provide a novel perspective on meditation and psychedelics that may reveal potential novel brain markers for positive synergistic effects between mindfulness practices and psilocybin.

Psychedelics for acquired brain injury: a review of molecular mechanisms and therapeutic potential

Acquired brain injury (ABI), such as traumatic brain injury and stroke, is a leading cause of disability worldwide, resulting in debilitating acute and chronic symptoms, as well as an increased risk of developing neurological and neurodegenerative disorders. These symptoms can stem from various neurophysiological insults, including neuroinflammation, oxidative stress, imbalances in neurotransmission, and impaired neuroplasticity. Despite advancements in medical technology and treatment interventions, managing ABI remains a significant challenge. Emerging evidence suggests that psychedelics may rapidly improve neurobehavioral outcomes in patients with various disorders that share physiological similarities with ABI. However, research specifically focussed on psychedelics for ABI is limited. This narrative literature review explores the neurochemical properties of psychedelics as a therapeutic intervention for ABI, with a focus on serotonin receptors, sigma-1 receptors, and neurotrophic signalling associated with neuroprotection, neuroplasticity, and neuroinflammation. The promotion of neuronal growth, cell survival, and anti-inflammatory properties exhibited by psychedelics strongly supports their potential benefit in managing ABI. Further research and translational efforts are required to elucidate their therapeutic mechanisms of action and to evaluate their effectiveness in treating the acute and chronic phases of ABI.

Psilocybin, an Effective Treatment for Major Depressive Disorder in Adults - A Systematic Review

Psilocybin is a classical psychedelic which has been utilised for healing purposes for millenia. However, with its classification as a Schedule I substance, research into this compound is scarce with few FDA-approved clinical studies. Despite this, profound findings into its antidepressant effects (largely through its action on 5-HT1a receptors) in mental illnesses such as major depressive disorder have rapidly increased interest back into their potential therapeutic benefits. This systematic review provides an analysis of the studies examining the clinical use of psilocybin for major depressive disorder. In total 6 studies were selected, including 319 participants, with half being randomised controlled trials and half open label trials. In every study psychological support was included as an integral part of the treatment. It was found that every study significantly favoured the use of psilocybin in reducing depressive symptoms, with few side effects. This gives psilocybin an advantage over commonly prescribed selective serotonin reuptake inhibitors (SSRIs), which carry more risk and cause more adverse effects. This drug therefore shows promise for being used as a clinical treatment for major depressive disorder, however future research should develop a paradigm for its use, with the timing of sessions and type of psychological support specified to allow for more precise analysis of the clinical effects of the drug. Additionally, more studies into its clinical efficacy are needed for appropriate detection of any publication bias. With this, psilocybin could prove to be revolutionary in treating depression and become an alternative medication to SSRIs.

Multimodal Neuroimaging of the Effect of Serotonergic Psychedelics on the Brain

The neurobiological mechanisms underpinning psychiatric disorders such as treatment-resistant major depression, post-traumatic stress disorder, and substance use disorders, remain unknown. Psychedelic compounds, such as psilocybin, lysergic acid diethylamide, and N,N-dimethyltryptamine, have emerged as potential therapies for these disorders because of their hypothesized ability to induce neuroplastic effects and alter functional networks in the brain. Yet, the mechanisms underpinning the neurobiological treatment response remain obscure. Quantitative neuroimaging is uniquely positioned to provide insight into the neurobiological mechanisms of these emerging therapies and quantify the patient treatment response. This review aims to synthesize our current state-of-the-art understanding of the functional changes occurring in the brain following psilocybin, lysergic acid diethylamide, or N,N-dimethyltryptamine administration in human participants with fMRI and PET. We further aim to disseminate our understanding of psychedelic compounds as they relate to neuroimaging with the goal of improved diagnostics and treatment of neuropsychiatric illness.

Psilocybin-induced changes in neural reactivity to alcohol and emotional cues in patients with alcohol use disorder: an fMRI pilot study

This pilot study investigated psilocybin-induced changes in neural reactivity to alcohol and emotional cues in patients with alcohol use disorder (AUD). Participants were recruited from a phase II, randomized, double-blind, placebo-controlled clinical trial investigating psilocybin-assisted therapy (PAT) for the treatment of AUD (NCT02061293). Eleven adult patients completed task-based blood oxygen dependent functional magnetic resonance imaging (fMRI) approximately 3 days before and 2 days after receiving 25 mg of psilocybin (n = 5) or 50 mg of diphenhydramine (n = 6). Visual alcohol and emotionally valanced (positive, negative, or neutral) stimuli were presented in block design. Across both alcohol and emotional cues, psilocybin increased activity in the medial and lateral prefrontal cortex (PFC) and left caudate, and decreased activity in the insular, motor, temporal, parietal, and occipital cortices, and cerebellum. Unique to negative cues, psilocybin increased supramarginal gyrus activity; unique to positive cues, psilocybin increased right hippocampus activity and decreased left hippocampus activity. Greater PFC and caudate engagement and concomitant insula, motor, and cerebellar disengagement suggests enhanced goal-directed action, improved emotional regulation, and diminished craving. The robust changes in brain activity observed in this pilot study warrant larger neuroimaging studies to elucidate neural mechanisms of PAT.Trial registration: NCT02061293.

The effect of cognitive training on children with attention deficit and hyperactivity disorder: A meta-analysis

OBJECTIVE

This document is a meta-analysis of randomized controlled trials that evaluated the effect of cognitive training interventions on attention deficit and hyperactivity disorder (ADHD) symptoms.

METHODS

A systematic literature search was conducted using databases such as PubMed, Web of Science, and Embase from the inception of each database to April 28, 2022. Data were analyzed using Stata 15 software. The risk of bias assessment was conducted using five domains from the Cochrane Collaborations tool.

RESULTS

A total of 10 studies with 446 children with ADHD were included. The results showed that cognitive training was effective in improving attention symptoms [SMD= -0.78 (95% CI: -1.46, -0.1)] and executive function [SMD = -0.3 (95% CI: -0.56, -0.05)] in children with ADHD compared to controls. No significant difference in the degree of improvement in hyperactivity/impulsivity with cognitive training compared to the control group [SMD = -0.65 (95% CI: -1.35, 0.05)]. In addition, subgroup analyses also found that cognitive training significantly improved attention in children with ADHD <10 years of age [SMD = -1.3 (95% CI: -2.58, -0.02)] and children with ADHD with length of training >30 days [SMD = -0.94 (95% CI: -1.81, -0.07)] compared to controls.

CONCLUSION

This meta-analysis found that the beneficial effects of cognitive training on attention (particularly for children with ADHD <10 years old and >30 days of training) and executive function in children with ADHD, but not on hyperactivity/impulsivity.

Mindfulness meditation and psychedelics: potential synergies and commonalities

There has been increasing scientific and clinical interest in studying psychedelic and meditation-based interventions in recent years, both in the context of improving mental health and as tools for understanding the mind. Several authors suggest neurophysiological and phenomenological parallels and overlaps between psychedelic and meditative states and suggest synergistic effects of both methods. Both psychedelic-assisted therapy and meditation training in the form of mindfulness-based interventions have been experimentally validated with moderate to large effects as alternative treatments for a variety of mental health problems, including depression, addictions, and anxiety disorders. Both demonstrated significant post-acute and long-term decreases in clinical symptoms and enhancements in well-being in healthy participants, in addition. Postulated shared salutogenic mechanisms, include, among others the ability to alter self-consciousness, present-moment awareness and antidepressant action via corresponding neuromodulatory effects. These shared mechanisms between mindfulness training and psychedelic intervention have led to scientists theorizing, and recently demonstrating, positive synergistic effects when both are used in combination. Research findings suggest that these two approaches can complement each other, enhancing the positive effects of both interventions. However, more theoretical accounts and methodologically sound research are needed before they can be extended into clinical practice. The current review aims to discuss the theoretical rationale of combining psychedelics with mindfulness training, including the predictive coding framework as well as research findings regarding synergies and commonalities between mindfulness training and psychedelic intervention. In addition, suggestions how to combine the two modalities are provided.

A Comprehensive Review of the Current Status of the Cellular Neurobiology of Psychedelics

Psychedelic substances have gained significant attention in recent years for their potential therapeutic effects on various psychiatric disorders. This review delves into the intricate cellular neurobiology of psychedelics, emphasizing their potential therapeutic applications in addressing the global burden of mental illness. It focuses on contemporary research into the pharmacological and molecular mechanisms underlying these substances, particularly the role of 5-HT2A receptor signaling and the promotion of plasticity through the TrkB-BDNF pathway. The review also discusses how psychedelics affect various receptors and pathways and explores their potential as anti-inflammatory agents. Overall, this research represents a significant development in biomedical sciences with the potential to transform mental health treatments.

Altered State of Consciousness and Mental Imagery as a Function of N, N-dimethyltryptamine Concentration in Ritualistic Ayahuasca Users

Consumption of the psychedelic brew ayahuasca is a central ritualistic aspect of the Santo Daime religion. The current observational, baseline controlled study was designed to assess whether members (n = 24) of the Santo Daime church would show enhanced capacity for mental imagery during an ayahuasca experience. In addition, this study assessed whether the effects of ayahuasca on consciousness and mental imagery were related to peak serum concentration of N, N-dimethyltryptamine (DMT), the main psychoactive component. Measures of altered states of consciousness (5-Dimensional Altered States of Consciousness Questionnaire) and ego dissolution (Ego Dissolution Inventory [EDI]) as well as measures of mental imagery (visual perspective shifting, vividness of visual imagery, cognitive flexibility, associative thinking) were taken on two subsequent days on which members of Santo Daime were sober or drank a self-selected volume of ayahuasca. Measures of altered states of consciousness revealed that feelings of oceanic boundlessness, visual restructuralization, and EDI increased most prominently after drinking and shared a positive correlation with peak DMT concentration. Measures of mental imagery did not noticeably differ between the baseline and ayahuasca condition, although subjective ratings of cognitive flexibility were lower under ayahuasca. Two measures related to mental imagery, that is, perspective shifts and cognitive flexibility, were significantly correlated to peak DMT concentrations. Peak concentrations of DMT and other alkaloids did not correlate with ayahuasca dose. These findings confirm previous notions that the primary phenomenological characteristics of ayahuasca are driven by DMT. Compensatory or neuroadaptive effects associated with long-term ayahuasca intake may have mitigated the acute impact of ayahuasca in Santo Daime members on mental imagery.

Lysergic Acid Diethylamide (LSD) for the Treatment of Anxiety Disorders: Preclinical and Clinical Evidence

Anxiety disorders (ADs) represent the sixth leading cause of disability worldwide, resulting in a significant global economic burden. Over 50% of individuals with ADs do not respond to standard therapies, making the identification of more effective anxiolytic drugs an ongoing research priority. In this work, we review the preclinical literature concerning the effects of lysergic acid diethylamide (LSD) on anxiety-like behaviors in preclinical models, and the clinical literature on anxiolytic effects of LSD in healthy volunteers and patients with ADs. Preclinical and clinical findings show that even if LSD may exacerbate anxiety acutely (both in "microdoses" and "full doses"), it induces long-lasting anxiolytic effects. Only two randomized controlled trials combining LSD and psychotherapy have been performed in patients with ADs with and without life-threatening conditions, showing a good safety profile and persisting decreases in anxiety outcomes. The effect of LSD on anxiety may be mediated by serotonin receptors (5-HT1A/1B, 5-HT2A/2C, and 5-HT7) and/or transporter in brain networks and circuits (default mode network, cortico-striato-thalamo-cortical circuit, and prefrontal cortex-amygdala circuit), involved in the modulation of anxiety. It remains unclear whether LSD can be an efficacious treatment alone or only when combined with psychotherapy, and if "microdosing" may elicit the same sustained anxiolytic effects as the "full doses". Further randomized controlled trials with larger sample size cohorts of patients with ADs are required to clearly define the effective regimens, safety profile, efficacy, and feasibility of LSD for the treatment of ADs.

Psychedelic unselfing: self-transcendence and change of values in psychedelic experiences

Psychedelic experiences have been shown to both facilitate (re)connection to one's values and change values, including enhancing aesthetic appreciation, promoting pro-environmental attitudes, and encouraging prosocial behavior. This article presents an empirically informed framework of philosophical psychology to understand how self-transcendence relates to psychedelic value changes. Most of the observed psychedelic value changes are toward the self-transcendent values of Schwartz's value theory. As psychedelics also reliably cause various self-transcendent experiences (STEs), a parsimonious hypothesis is that STEs change values toward self-transcendent values. I argue that STEs indeed can lead to value changes, and discuss the morally relevant process of self-transcendence through Iris Murdoch's concept of "unselfing". I argue that overt egocentric concerns easily bias one's valuations. Unselfing reduces egocentric attributions of salience and enhances non-egocentric attention to the world, widening one's perspective and shifting evaluation toward self-transcendent modes. Values are inherently tied to various evaluative contexts, and unselfing can attune the individual to evaluative contexts and accompanying values beyond the self. Understood this way, psychedelics can provide temporarily enhanced access to self-transcendent values and function as sources of aspiration and value change. However, contextual factors can complicate whether STEs lead to long-term changes in values. The framework is supported by various research strands establishing empirical and conceptual connections between long-term differences in egocentricity, STEs, and self-transcendent values. Furthermore, the link between unselfing and value changes is supported by phenomenological and theoretical analysis of psychedelic experiences, as well as empirical findings on their long-term effects. This article furthers understanding of psychedelic value changes and contributes to discussions on whether value changes are justified, whether they result from cultural context, and whether psychedelics could function as tools of moral neuroenhancement.

Effect of LSD and music on the time-varying brain dynamics

RATIONALE

Psychedelics are getting closer to being widely used in clinical treatment. Music is known as a key element of psychedelic-assisted therapy due to its psychological effects, specifically on the emotion, meaning-making, and sensory processing. However, there is still a lack of understanding in how psychedelics influence brain activity in experimental settings involving music listening.

OBJECTIVES

The main goal of our research was to investigate the effect of music, as a part of "setting," on the brain states dynamics after lysergic acid diethylamide (LSD) intake.

METHODS

We used an open dataset, where a group of 15 participants underwent two functional MRI scanning sessions under LSD and placebo influence. Every scanning session contained three runs: two resting-state runs separated by one run with music listening. We applied K-Means clustering to identify the repetitive patterns of brain activity, so-called brain states. For further analysis, we calculated states' dwell time, fractional occupancy and transition probability.

RESULTS

The interaction effect of music and psychedelics led to change in the time-varying brain activity of the task-positive state. LSD, regardless of the music, affected the dynamics of the state of combined activity of DMN, SOM, and VIS networks. Crucially, we observed that the music itself could potentially have a long-term influence on the resting-state, in particular on states involving task-positive networks.

CONCLUSIONS

This study indicates that music, as a crucial element of "setting," can potentially have an influence on the subject's resting-state during psychedelic experience. Further studies should replicate these results on a larger sample size.

The effect of seed location on functional connectivity: evidence from an image-based meta-analysis

Introduction

Default mode network (DMN) is the most involved network in the study of brain development and brain diseases. Resting-state functional connectivity (rsFC) is the most used method to study DMN, but different studies are inconsistent in the selection of seed. To evaluate the effect of different seed selection on rsFC, we conducted an image-based meta-analysis (IBMA).

Methods

We identified 59 coordinates of seed regions of interest (ROIs) within the default mode network (DMN) from 11 studies (retrieved from Web of Science and Pubmed) to calculate the functional connectivity; then, the uncorrected t maps were obtained from the statistical analyses. The IBMA was performed with the t maps.

Results

We demonstrate that the overlap of meta-analytic maps across different seeds' ROIs within DMN is relatively low, which cautions us to be cautious with seeds' selection.

Discussion

Future studies using the seed-based functional connectivity method should take the reproducibility of different seeds into account. The choice of seed may significantly affect the connectivity results.

Safety, tolerability, and clinical and neural effects of single-dose psilocybin in obsessive-compulsive disorder: protocol for a randomized, double-blind, placebo-controlled, non-crossover trial

Background

Psilocybin may help treat obsessive-compulsive disorder (OCD). To date, only one open-label study of psilocybin for OCD exists, necessitating further investigation with a randomized controlled design. The neural correlates of psilocybin's effects on OCD have also not been studied.

Objectives

This first-of-its-kind trial aims to evaluate the feasibility, safety, and tolerability of psilocybin in the treatment of OCD, provide preliminary evidence on the effects of psilocybin on OCD symptoms, and elucidate neural mechanisms that may mediate psilocybin's effects on OCD.

Design

We use a randomized (1:1), double-blind, placebo-controlled, non-crossover design to examine the clinical and neural effects of either a single dose of oral psilocybin (0.25 mg/kg) or active placebo-control agent (250 mg of niacin) on OCD symptoms.

Methods and analysis

We are enrolling 30 adult participants at a single site in Connecticut, USA who have failed at least one trial of standard care treatment (medication/psychotherapy) for OCD. All participants will also receive unstructured, non-directive psychological support during visits. Aside from safety, primary outcomes include OCD symptoms over the past 24 h, assessed by the Acute Yale-Brown Obsessive-Compulsive Scale and Visual Analog Scale ratings. These are collected by blinded, independent raters at baseline and the primary endpoint of 48 h post-dosing. Total follow-up is 12 weeks post-dosing. Resting state neuroimaging data will be collected at baseline and primary endpoint. Participants randomized to placebo will be offered the chance to return for an open-label dose of 0.25 mg/kg.

Ethics statement

All participants will be required to provide written informed consent. The trial (protocol v. 5.2) was approved by the institutional review board (HIC #2000020355) and registered with ClinicalTrials.gov (NCT03356483).

Discussion

This study may represent an advance in our ability to treat refractory OCD, and pave the way for future studies of neurobiological mechanisms of OCD that may respond to psilocybin.

Not in the drug, not in the brain: Causality in psychedelic experiences from an enactive perspective

Psychedelics are psychoactive substances that receive renewed interest from science and society. Increasing empirical evidence shows that the effects of psychedelics are associated with alterations in biochemical processes, brain activity, and lived experience. Still, how these different levels relate remains subject to debate. The current literature presents two influential views on the relationship between the psychedelic molecule, neural events, and experience: The integration view and the pluralistic view. The main aim of this article is to contribute a promising complementary view by re-evaluating the psychedelic molecule-brain-experience relationship from an enactive perspective. We approach this aim via the following main research questions: (1) What is the causal relationship between the psychedelic drug and brain activity? (2) What is the causal relationship between brain activity and the psychedelic experience? In exploring the first research question, we apply the concept of autonomy to the psychedelic molecule-brain relationship. In exploring the second research question, we apply the concept of dynamic co-emergence to the psychedelic brain-experience relationship. Addressing these two research questions from an enactive position offers a perspective that emphasizes interdependence and circular causality on multiple levels. This enactive perspective not only supports the pluralistic view but enriches it through a principled account of how multi-layered processes come to interact. This renders the enactive view a promising contribution to questions around causality in the therapeutic effects of psychedelics with important implications for psychedelic therapy and psychedelic research.

Optimizing outcomes in psilocybin therapy: Considerations in participant evaluation and preparation

Recent studies have demonstrated the promise of psilocybin therapies in creating positive changes for those with poor mental health across multiple diagnostic categories, including major depressive disorder (MDD), end-of-life anxiety, and obsessive-compulsive disorder (OCD). While there may be a large population that is eligible to participate in psilocybin therapy based on psychiatric diagnosis and medical clearance, little attention has been given to intrapersonal and interpersonal factors that might influence patient's readiness (i.e., eligibility and capacity) for psychedelic interventions. This paper proposes that readiness assessment includes both intrapersonal and interpersonal factors in order to improve safety, patient care, and treatment outcomes. While at the present time a reliable and valid instrument has not been developed, we propose that three specific areas of focus - patient presentation, therapeutic alliance, and patient safety - may be used to establish a patient's readiness for psilocybin therapy, thus increasing therapy optimization and personalization.

Psychedelic-Assisted Therapy and Psychedelic Science: A Review and Perspective on Opportunities in Neurosurgery and Neuro-Oncology

After a decades-long pause, psychedelics are again being intensely investigated for treating a wide range of neuropsychiatric ailments including depression, anxiety, addiction, post-traumatic stress disorder, anorexia, and chronic pain syndromes. The classic serotonergic psychedelics psilocybin and lysergic acid diethylamide and nonclassic psychedelics 3,4-methylenedioxymethamphetamine and ketamine are increasingly appreciated as neuroplastogens given their potential to fundamentally alter mood and behavior well beyond the time window of measurable exposure. Imaging studies with psychedelics are also helping advance our understanding of neural networks and connectomics. This resurgence in psychedelic science and psychedelic-assisted therapy has potential significance for the fields of neurosurgery and neuro-oncology and their diverse and challenging patients, many of whom continue to have mental health issues and poor quality of life despite receiving state-of-the-art care. In this study, we review recent and ongoing clinical trials, the set and setting model of psychedelic-assisted therapy, potential risks and adverse events, proposed mechanisms of action, and provide a perspective on how the safe and evidence-based use of psychedelics could potentially benefit many patients, including those with brain tumors, pain syndromes, ruminative disorders, stroke, SAH, TBI, and movement disorders. By leveraging psychedelics' neuroplastic potential to rehabilitate the mind and brain, novel treatments may be possible for many of these patient populations, in some instances working synergistically with current treatments and in some using subpsychedelic doses that do not require mind-altering effects for efficacy. This review aims to encourage broader multidisciplinary collaboration across the neurosciences to explore and help realize the transdiagnostic healing potential of psychedelics.