Classic psychedelics: An integrative review of epidemiology, therapeutics, mystical experience, and brain network function

The intensity of the psychedelic experience is reliably associated with clinical improvements: A systematic review and meta-analysis

BACKGROUND

Psychedelic-assisted therapies have demonstrated promising results in treating mental disorders, with results suggesting that the subjective intensity and quality of psychedelic experiences plays a significant role in mediating therapeutic effects. However, the strength of this association across diagnoses and treatment settings remains underexplored.

METHODS

We searched MEDLINE, Embase, and PsycINFO databases for studies examining the correlation between the intensity of the psychedelic experience and clinical outcomes in patients treated with classical psychedelics. Meta-correlations were performed, and standardized mean differences of psychedelic experience intensity scores were compared between clinical responders and non-responders using random-effects models. Subgroup analyses were conducted based on diagnosis, study design, setting (clinical vs. naturalistic), and substance used.

RESULTS

A significant positive correlation was found between the intensity of mystical experiences and clinical improvement across all studies (r = .33, p < .0001). Subgroup analyses revealed a stronger association (p = .02) for mood disorders (r = .41) compared to addictions (r = .19). The effect was greater (p < .01) in protocol-based clinical settings (r = .50) than in naturalistic use (r = .14). Prospective designs showed stronger (p < .01) correlations (r = .43) compared to retrospective designs (r = .14).

CONCLUSION

The intensity of psychedelic experiences is significantly and reliably associated with therapeutic outcomes, particularly in mood disorders. Clinical settings and prospective study designs strengthen this relationship, emphasizing the importance of controlled environments and therapeutic support to fully benefit from the therapeutic potential of psychedelics.

Connectome harmonic decomposition tracks the presence of disconnected consciousness during ketamine-induced unresponsiveness

BACKGROUND

Ketamine, in doses suitable to induce anaesthesia in humans, gives rise to a unique state of unresponsiveness accompanied by vivid experiences and sensations, making it possible to disentangle the correlated but distinct concepts of conscious awareness and behavioural responsiveness. This distinction is often overlooked in the study of consciousness.

METHODS

The mathematical framework of connectome harmonic decomposition (CHD) was used to view functional magnetic resonance imaging (fMRI) signals during ketamine-induced unresponsiveness as distributed patterns across spatial scales. The connectome harmonic signature of this particular state was mapped onto signatures of other states of consciousness for comparison.

RESULTS

An increased prevalence of fine-grained connectome harmonics was found in fMRI signals obtained during ketamine-induced unresponsiveness, indicating higher granularity. After statistical assessment, the ketamine sedation harmonic signature showed alignment with signatures of LSD-induced (fixed effect =0.0113 [0.0099, 0.0127], P<0.001) or ketamine-induced (fixed effect =0.0087 [0.0071, 0.0103], P<0.001) psychedelic states, and misalignment with signatures seen in unconscious individuals owing to propofol sedation (fixed effect =-0.0213 [-0.0245, -0.0181], P<0.001) or brain injury (fixed effect =-0.0205 [-0.0234, -0.0178], P<0.001).

CONCLUSIONS

The CHD framework, which only requires resting-state fMRI data and can be applied retrospectively, has the ability to track alterations in conscious awareness in the absence of behavioural responsiveness on a group level. This is possible because of ketamine's unique property of decoupling these two facets, and is important for consciousness and anaesthesia research.

The road to Aha: A recipe for mental breakthroughs

We present a novel framework for understanding the diverse spectrum of mental breakthrough events, ranging from problem-solving insights to profound personal transformations. We propose that these events, while varied in expression and impact, share common underlying mechanisms of representational change. We also hypothesise that the differences in phenomenological intensity can be conceptualized along a continuum. Central to our model are three core components - tension, altered salience, and enhanced flexibility - which we identify as essential prerequisites for significant cognitive restructuring. These components interact within an iterative cycle, influencing both the emergence and nature of insight experiences. Drawing on examples from different fields, we explore how a conflict between existing models can trigger this cycle, wherein mechanisms of attention allocation and relaxation of constraints work in tandem to facilitate the emergence of insights. Furthermore, we propose that the intensity of the "aha-moment" and the breadth of its impact are contingent on how central the conflict is within one's conceptual landscape and the extent to which existing mental models are challenged. Thus, the model accounts for both the subtle, momentary insights in problem-solving and the transformative realizations that reshape core beliefs and self-perception. By synthesising insights from various domains, including psychotherapy, contemplative science, and psychedelic research, we present a theoretical account with broad scope, aiming to shed light on the complex processes that can lead to a wide array of mental breakthroughs, thereby contributing to the understanding of insight phenomena across disciplines.

Sporadic use of classic psychedelics and neuropsychological performance: A cross-sectional analysis

BACKGROUND

Evidence on the neuropsychological consequences of classic psychedelics like psilocybin, LSD, and ayahuasca is conflicting, and little is known about how sporadic use of psychedelics under naturalistic conditions may affect cognitive functioning. Given the growing interest in the therapeutic potential of psychedelics and the rise in non-medical use, further exploration into their neuropsychological effects is needed.

METHODS

This cross-sectional, exploratory study employed a comprehensive neuropsychological test battery to assess cognitive domains such as executive function, memory, attention, and visuospatial abilities among individuals with mild to moderate lifetime use of psychedelics. Analyses compared all users to non-users, moderate users to matched controls, and adjusted dose-response analyses were conducted within the users group.

RESULTS

From 2611 screened individuals, N = 136 participants (84 psychedelic users and 52 controls) were included. Participants were aged 18-50 years. Neuropsychological performance was broadly equivalent between users and controls. However, matched-pair analyses showed that psychedelic users had a modest advantage in executive functions, especially superior performance on the Wisconsin Card Sorting Test (WCST) (p < .05). Dose-response analyses further corroborated these findings, indicating a positive association between lifetime psychedelic use and performance on the WCST, specifically total errors (p < .001), perseverative responses (p < .001), perseverative errors (p < .001), non-perseverative errors (p = .008), and conceptual level responses (p = .004).

CONCLUSIONS

The study did not detect any negative associations between sporadic lifetime psychedelic use and cognition. Instead, a moderate association with executive functioning was found, indicating increased cognitive flexibility in users. Dose-response analyses further supported this relationship.

From Stress to Synapse: The Neuronal Atrophy Pathway to Mood Dysregulation

Mood disorders, including major depressive disorder and bipolar disorder, are among the most prevalent mental health conditions globally, yet their underlying mechanisms remain incompletely understood. This review critically examines the neuronal atrophy hypothesis, which posits that chronic stress and associated neurobiological changes lead to structural and functional deficits in critical brain regions, contributing to mood disorder pathogenesis. Key mechanisms explored include dysregulation of neurotrophic factors such as brain-derived neurotrophic factor (BDNF), elevated glucocorticoids from stress responses, neuroinflammation mediated by cytokines, and mitochondrial dysfunction disrupting neuronal energy metabolism. These processes collectively impair synaptic plasticity, exacerbate structural atrophy, and perpetuate mood dysregulation. Emerging evidence from neuroimaging, genetic, and epigenetic studies underscores the complexity of these interactions and highlights the role of environmental factors such as early-life stress and urbanization. Furthermore, therapeutic strategies targeting neuroplasticity, including novel pharmacological agents, lifestyle interventions, and anti-inflammatory treatments, are discussed as promising avenues for improving patient outcomes. Advancing our understanding of the neuronal atrophy hypothesis could lead to more effective, sustainable interventions for managing mood disorders and mitigating their global health burden.

A prospective ecological momentary assessment study of an ayahuasca retreat: exploring the salutary impact of acute psychedelic experiences on subacute affect and mindfulness skills in daily life

RATIONALE

To examine the acute effects of ayahuasca use and their relationship to sub-acute changes in affect and mindfulness in a non-clinical sample, addressing the need for a better understanding of ayahuasca's immediate and short-term impacts as interest in its use grows.

OBJECTIVES

Using prospective ecological assessment, this study investigates how ayahuasca used at a 4-day retreat affects positive/negative affect and mindfulness skills in daily living compared to pre-retreat. Additionally, we explore acute psychedelic experiences during the ayahuasca retreat, assessed retrospectively 1-2 days post-retreat, as potential mechanisms for theorized effects in daily living post-retreat.

METHODS

Thirty-six participants reported positive/negative affect and mindfulness skills three times daily for 5 days before and after the retreat. Baseline assessments included lifetime psychedelic experience, and post-retreat assessments covered acute ayahuasca experiences. Mixed-effect linear models were used to analyze the data.

RESULTS

Post-retreat, we observed reduced negative affect, increased positive affect, and enhanced mindfulness skills in daily living. Ayahuasca-induced acute experiences, such as time/space transcendence, emotional breakthrough and challenging experiences predicted greater subacute positive affect. Notably, none of these experiences were linked to subacute improvements in negative affect or mindfulness. No participants showed clinically significant adverse responses post-retreat, and only 5.5% exhibited some degree of potentially clinically significant deterioration in affect.

CONCLUSIONS

Ayahuasca use may lead to improvement in mood and mindfulness skills, and key acute psychedelic experiences induced by ayahuasca may be important to some of these salutary effects, positive affect in particular.

Pharmacological characterization of cannabidiol as a negative allosteric modulator of the 5-HT2A receptor

Promising clinical evidence suggests that psychedelic compounds, like lysergic acid diethylamide (LSD), have therapeutic value for treatment of psychiatric disorders. However, they often produce hallucinations and dissociative states, likely mediated by the serotonin (5-HT) receptor 5-HT2A, raising challenges regarding therapeutic scalability. Given the reported antipsychotic effects of cannabidiol (CBD) and its promiscuous binding at many receptors, we assessed whether CBD could modulate 5-HT2A signalling. Activation of the 5-HT2A intracellular signalling events were assessed using resonance energy transfer- or fluorescence-based biosensors in HEK 293 cells and in rat primary cortical neurons. In 5-HT2A-transfected HEK 293 T cells, CBD antagonized LSD-mediated Gq activation in a saturable way, while leaving β-arrestin2 recruitment unaffected. CBD decreased Gq activation mediated by the 5-HT2A-specific agonist DOI as well as LSD-mediated activity in primary rat neonatal cortical neurons. Using Site Identification by Ligand Competitive Saturation (SILCS) simulations, we also predicted that the putative binding site of CBD overlapped with that of oleamide, a positive allosteric modulator of 5-HT2A, and could displace the binding of orthosteric ligands toward the external binding pocket. Based on these findings, we propose that CBD acts as a negative allosteric modulator of 5-HT2A.

Prolonged adverse effects from repeated psilocybin use in an underground psychedelic therapy training program: a case report

BACKGROUND

Psychedelic-assisted therapy has gained growing interest to improve a range of mental health outcomes. In response, numerous training programs have formed to train the necessary workforce to deliver psychedelic therapy. These include both legal and 'underground' (i.e., unregulated) programs that use psychedelics as part of their training. Prolonged adverse experiences (PAEs) may arise from psychedelic use, though they are poorly characterized in the clinical literature. Thus, understanding the potential harms related to psychedelic use is critical as psychedelic therapy training programs consider strategies to potentially integrate psychedelic use into therapy training.

CASE PRESENTATION

We present the case of a psychologist who underwent psychedelic therapy training that involved repeated high doses of psilocybin-containing mushrooms and subsequently developed prolonged adverse effects including severe sleep impairment, anhedonia, and suicidal ideation requiring hospitalization. Despite worsening symptoms, her psychedelic therapy trainers advised her against seeking psychiatric support, delaying treatment. Ultimately, the patient's symptoms resolved after a course of electroconvulsive therapy (ECT).

CONCLUSIONS

This case highlights the tensions between legal and underground psychedelic use within psychedelic therapy training programs, psychiatry and neo-shamanism, and the use of psychiatric interventions (i.e., ECT) and energy medicine to address prolonged adverse effects from psychedelics. Clinicians should be aware of these potential conflicts between psychiatric conceptualizations of PAEs and frameworks maintained in psychedelic community practices and their impacts on patients' presenting symptoms, decision making, and emotional challenges.

Phenethylaminylation: Preliminary In Vitro Evidence for the Covalent Transamidation of Psychedelic Phenethylamines to Glial Proteins using 3,5-Dimethoxy-4-(2-Propynyloxy)-Phenethylamine as a Model Compound

Psychedelics are well known for their ability to produce profoundly altered states of consciousness. But, more importantly, the effects of psychedelics can influence neurobehavioral changes that last well after these acute subjective effects end. This phenomenon is currently being leveraged in the development of psychedelic-assisted psychotherapies for the treatment of multiple neuropsychiatric disorders. The cellular and molecular mechanisms by which single doses of psychedelics are able to mediate long-term cognitive changes are an active area of research. We hypothesize that psychedelics contribute to long term changes in cellular state by covalently modifying proteins. This post-translational modification by psychedelics is possible through the transglutaminase-mediated transamidation of their amine termini to glutamine carboxamide residues. Here, we synthesize and utilize a propargylated analogue of mescaline - the classic serotonergic psychedelic phenethylamine found in cacti species - to identify putative protein targets of psychedelic modifications through the use of click-chemistry in a primary human astrocyte cell culture model. Our preliminary findings indicate that a diverse array of glial proteins may be substrates for transglutaminase 2-mediated monoaminylation by our model phenethylamine ("phenethylaminylation"). Based on these points, we speculatively highlight new directions for the study of this putative noncanonical psychedelic activity.

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.

The Therapeutic Potential of Psychedelics in Treating Substance Use Disorders: A Review of Clinical Trials

Background and Objectives: Substance use disorders (SUDs) affect millions worldwide. Despite increasing drug use, treatment options remain limited. Psychedelic-assisted therapy (PAT), integrating psychedelic substances with psychotherapy, offers a promising alternative by addressing underlying neural mechanisms. Materials and Methods: This review's purpose is to investigate the current understanding of psychedelic therapy for treating SUDs, including tobacco, alcohol, and drug addiction. The systematic review approach focused on clinical trials and randomized controlled trials conducted from 2013 to 2023. The search was performed using PubMed, Google Scholar, and Consensus AI, following PRISMA guidelines. Studies involving psychedelics like LSD, psilocybin, ibogaine, and ayahuasca for treating various addictions were included, excluding naturalistic studies and reviews. Results: Our results highlight the key findings from 16 clinical trials investigating psychedelic therapy for SUDs. Psychedelics like psilocybin and ayahuasca showed promise in reducing alcohol and tobacco dependence, with psilocybin being particularly effective in decreasing cravings and promoting long-term abstinence. The studies revealed significant improvements in substance use reduction, especially when combined with psychotherapy. However, the variability in dosages and study design calls for more standardized approaches. These findings emphasize the potential of psychedelics in SUD treatment, though further large-scale research is needed to validate these results and develop consistent protocols. Conclusions: This research reviewed the past decade's international experience, emphasizing the growing potential of psychedelic therapy in treating SUDs pertaining to alcohol, tobacco, and cocaine dependence. Psychedelics such as psilocybin and ketamine can reduce cravings and promote psychological well-being, especially when combined with psychotherapy. However, regulatory barriers and specialized clinical training are necessary to integrate these therapies into mainstream addiction treatment safely. Psychedelics offer a promising alternative for those unresponsive to conventional methods.

Therapeutic Potential of MDMA- and Psychedelic-Assisted Psychotherapy for Adolescent Depression and Trauma

PURPOSE OF REVIEW

There is a mental health crisis affecting youth, and the utility of existing treatments is often limited by lack of effectiveness and tolerability. The aim of this review is to report on outcomes of clinical trials for psilocybin-assisted psychotherapy for adults with depression and MDMA-assisted psychotherapy for adults with post-traumatic stress disorder (PTSD) and discuss recommendations for exploring these treatments in adolescent populations.

RECENT FINDINGS

There have been encouraging data supporting the use of psilocybin-assisted psychotherapy for depression, including previously treatment-resistant symptoms. MDMA-assisted psychotherapy is showing similar promise in treating PTSD, with excellent response and remission rates that appear durable. However, no studies have looked at the use of these treatments in younger patients. The safety and efficacy of psychedelic- and MDMA-assisted psychotherapies should be investigated in adolescents, especially considering the burden of untreated and undertreated psychiatric illness in youth, and the benefits of a potentially earlier, more effective, and more tolerable recovery process. Research and implementation should be tailored to the needs of this population, and equity and access should be considered at every stage. In this novel and rapidly evolving landscape, the psychiatric community is encouraged to advocate for safe, appropriate, and inclusive inquiry into, and application and scaling of these treatment models in adolescent patients.

Exploring the role of psychedelic-assisted therapy in enhancing spirituality and mystical experiences in patients with life-threatening illnesses: A systematic review

INTRODUCTION

Psychedelic-Assisted Therapy (PAT) is gaining traction as a novel approach to addressing the psychological and existential distress experienced by patients.

OBJECTIVES

This systematic review aimed to investigate the impact of PAT on spirituality, mystical experiences, and spiritual well-being (SpWB) in patients with life-threatening, incurable, or terminal illnesses.

METHODS

A comprehensive search was conducted across PubMed, Web of Science, and Cochrane databases to identify relevant studies published between 2013 and 2023. The study population comprised patients diagnosed with life-threatening illnesses. Various forms of PAT, encompassing both typical and atypical psychedelic substances, were considered as interventions, with no specific comparators outlined. The primary outcomes of interest included spirituality, mystical experience, and SpWB. Risk of bias assessment was performed using Cochrane's tools.

RESULTS

Six studies with a high risk of bias were included in the review, all conducted in the United States of America, involving 140 patients, the majority of whom had cancer (99 %). PAT, especially with psilocybin, demonstrated significant enhancements in spirituality, mystical experiences, and SpWB. Notably, SpWB showed improvements in all studies which assessed this spiritual outcome following PAT. Mystical experiences were correlated with improvements in spirituality in one study.

CONCLUSIONS

This systematic review underscores the potential of PAT to address unmet spiritual needs and enhance SpWB in patients with life-threatening illnesses. However, further research is needed to elucidate the mechanisms underlying these therapeutic effects. Rigorous evaluation of healthcare practitioners' role in guiding patients through PAT protocols is essential to ensure safe and effective implementation in palliative care settings.

Impact of psychedelics on craving in addiction: A systematic review

BACKGROUND

In the context of the need to increase treatment options for substance use disorders, recent research has evaluated the therapeutic potential of psychedelics. However, there is an incomplete understanding of psychedelics' effects on craving, a core symptom of addictive disorders and a predictor of substance use and relapse.

AIMS

To determine if the use of psychedelics is associated with changes in craving in humans.

METHODS

A systematic review of the literature, using PubMed, PsycInfo, and Scopus databases up to May 2023. We included all studies assessing any substance craving levels after psychedelic use (protocol registration number CRD42021242856).

RESULTS

Thirty-eight published articles were included, corresponding to 31 studies and 2639 participants, pertaining either to alcohol, opioid, cocaine, or tobacco use disorders. Twelve of the 31 included studies reported a significant decrease in craving scores following psychedelic use. All but two studies had methodological issues, leading to moderate to high risk of bias scores.

CONCLUSIONS

Some psychedelics may show promising anti-craving effects, yet the diversity and high risk of bias of extant studies indicate that these results are to be considered with caution. Further well-controlled and larger-scale trials should be encouraged.

Cosmology of belonging: The role of community in the therapeutic use of psychedelics

BACKGROUND

The recent wave of clinical trials of psychedelic substances among patients with life-limiting illness has largely focused on individual healing. This most often translates to a single patient receiving an intervention with researchers guiding them. As social isolation and lack of connection are major drivers of current mental health crises and group work is expected to be an important aspect of psychedelic assisted psychotherapy, it is essential that we understand the role of community in psychedelic healing.

OBJECTIVES

To explore how psychedelic guides in the United States discuss the role of "community" in naturalistic psychedelic groups.

METHODS

This is a secondary qualitative data study of data from a larger modified ethnographic study of psychedelic plant medicine use in the US. Fifteen facilitators of naturalistic psychedelic groups were recruited via snowball sampling. Content analysis was used to identify themes.

RESULTS

Participants viewed the concept of community as essential to every aspect of psychedelic work, from the motivation to use psychedelics, to the psychedelic dosing experience and the integration of lessons learned during psychedelic experiences into everyday life. Themes and subthemes were identified. Theme 1: The arc of healing through community (Subthemes: Community as intention, the group psychedelic journey experience, community and integration); Theme 2: Naturally occurring psychedelic communities as group therapy (Subthemes [as described in Table 2]: Belonging, authenticity, corrective experience, trust, touch).

SIGNIFICANCE

Results suggest that existing knowledge about therapeutic group processes may be helpful in structuring and optimizing group psychedelic work. More research is needed on how to leverage the benefit of community connection in the therapeutic psychedelic context, including size and composition of groups, selection and dosing of psychedelic substances in group settings, facilitator training, and role of community integration. Psychedelic groups may provide benefits that individual work does not support.

The Psych Behind Psychedelics: Exploring Hallucinogen Use as a Marker for Untreated Mental Health Disorders

Objective

Are individuals who use hallucinogens self-medicating their mental illness and are they more likely to abuse other illegal substances?

Design setting participants

Data from the National Survey on Drug Use and Health (NSDUH), collected by the Substance Abuse and Mental Health Services Administration (SAMHSA) database was queried for correlations with hallucinogen use. Using age group as a control variable, different variables were run through a crosstab in order to find significant data pointing to the implications of hallucinogen use.

Results

The data from the crosstab analysis showed three key findings about hallucinogen use: Those with mental illness or substance abuse issues were substantially more likely to use hallucinogens, the hallucinogen use greatly increased with the pandemic along with further mental health issues, and those who used hallucinogens were more significantly likely to abuse other illegal substances, primarily in a younger population.

Conclusion

The positive correlation between mental health issues and hallucinogen use emphasizes the need for better mental health services, especially after the COVID-19 pandemic.The positive correlation between hallucinogen use and other drug use indicates the widespread drug abuse problem, especially within a younger population in which drugs pose a larger neurological threat.

Possible Worlds Theory: How the Imagination Transcends and Recreates Reality

The imagination is central to human social life but undervalued worldwide and underexplored in psychology. Here, we offer Possible Worlds Theory as a synthetic theory of the imagination. We first define the imagination, mapping the mental states it touches, from dreams and hallucinations to satire and fiction. The conditions that prompt people to imagine range from trauma to physical and social deprivation, and they challenge the sense of reality, stirring a need to create possible worlds. We theorize about four cognitive operations underlying the structure of the mental states of the imagination. We then show how people embody the imagination in social behaviors such as pretense and ritual, which give rise to experiences of a special class of feelings defined by their freedom from reality. We extend Possible Worlds Theory to four domains-play, spirituality, morality, and art-and show how in flights of the imagination people create new social realities shared with others.

Rural-urban divide in risk perception of LSD: Implications for psychedelic-assisted therapy

BACKGROUND

Recent legislative initiatives in the United States have focused on the medical and legal status of psychedelics, prompting interest in understanding public perceptions of their risks. This study investigates rural-urban differences in the perception of LSD and cannabis risks using national survey data.

METHODS

Data from the National Survey of Drug Use and Health (NSDUH) between 2015 and 2021 were analyzed. Logistic regression models were used to compare risk perceptions of LSD and cannabis between rural and urban respondents, adjusting for relevant factors.

RESULTS

Rural residents were 1.2 to 1.4 times more likely to perceive using LSD once or twice as of great risk compared to urban residents during the survey period. However, the perception of monthly cannabis use as having great risk was slightly higher among rural residents only until 2019, with no significant differences observed in 2020 and 2021.

CONCLUSION

The study highlights a significant rural-urban divide in the perception of LSD risk, which could impact policymaking on psychedelic therapies. Understanding these differences is crucial for developing effective and equitable policies regarding psychedelic substances and treatments.

Psilocybin: From Psychiatric Pariah to Perceived Panacea

OBJECTIVE

The authors critically examine the evidence base for psilocybin administered with psychological support/therapy (PST) in the treatment of psychiatric disorders and offer practical recommendations to guide future research endeavors.

METHODS

PubMed was searched for English-language articles from January 1998 to November 2023, using the search term "psilocybin." A total of 1,449 articles were identified and screened through titles and abstracts. Of these, 21 unique open-label or randomized controlled trials (RCTs) were identified that examine psilocybin for the treatment of obsessive-compulsive and related disorders (N=2), anxiety/depression associated with a cancer diagnosis (N=5), major depressive disorder (MDD; N=8), substance use disorders (N=4), anorexia (N=1), and demoralization (i.e., hopelessness, helplessness, and poor coping) in AIDS survivors (N=1).

RESULTS

The most developed evidence base is for the treatment of MDD (three double-blind RCTs with positive signals spanning a range of severities). However, the evidence is tempered by threats to internal and external validity, including unsuccessful blinding, small samples, large variability in dosing and PST procedures, limited sample diversity, and possibly large expectancy effects. Knowledge of mechanisms of action and predictors of response is currently limited.

CONCLUSIONS

The evidence is currently insufficient to recommend psilocybin with PST as a psychiatric treatment. Additional rigorously designed clinical trials are needed to definitively establish efficacy in larger and more diverse samples, address dosing considerations, improve blinding, and provide information on mechanisms of action and moderators of clinical response. Head-to-head comparisons with other evidence-based treatments will better inform the potential future role of psilocybin with PST in the treatment of major psychiatric disorders.

Protective Behavioral Strategies for Psychedelic Use: A Mini Review of the Evidence

Background

Approximately 8.5 million Americans over the age of 12 endorsed past year psychedelic use in 2022, with 1.4 million individuals initiating use during this time. Although emerging evidence indicates there may be beneficial aspects of psychedelic use, there is a need to understand how individuals might mitigate potential risks within nonclinical contexts, such as through the use of protective behavioral strategies (PBS).

Method

PubMed and Google Scholar databases were searched to identify articles reporting on PBS (i.e., harm reduction strategies implemented at the individual level) for psychedelic use within nonclinical contexts. We include articles pertaining to both classical serotonergic psychedelics (e.g., lysergic acid diethylamide [LSD], psilocybin) and nonclassical psychedelics (e.g., 3,4-methylenedioxymethamphetamine [MDMA], ketamine).

Results

Although research on psychedelic PBS use is limited, evidence suggests a culture of harm reduction present within psychedelic communities. Psychedelic PBS identified in the literature include strategies related to drug acquisition, dosing, set and setting, bodily nourishment, planning for and working through challenging experiences, and integration of psychedelic experiences. Few studies have examined the relationship between psychedelic PBS use and outcomes, but emerging evidence suggests that psychedelic PBS use may be associated with decreased consequences.

Conclusion

There is a need to continue developing and validating measures of psychedelic PBS and outcomes for use within research and intervention settings. Additional research examining associations between psychedelic PBS use and outcomes is also critical to best serving the needs of individuals who use psychedelics within nonclinical contexts.

Leveraging meditation research for the study of psychedelic-related adverse effects

Psychedelics have shown early evidence for a range of benefits and low harm profiles in extant research. However, adverse effects (AEs) research in psychedelics has been limited, leading to underspecified AE profiles, inconsistent measurement, and potential undercounting of AEs. The development of safe, effective psychedelic therapies and treatments for AEs when they occur requires a thorough assessment of psychedelic-related AEs, their phenomenology, risk factors, and longitudinal duration. This article proposes that research on meditation-related AEs, which overlap in important ways with the phenomenological and contextual characteristics of psychedelic-related AEs, has engaged many methodological challenges present in the study of psychedelic-related AEs. Thus, meditation-related AE research offers thematic and methodological insights that are valuable to psychedelic AE research. An integrative review of extant AE research in both psychedelics and meditation is provided, and an agenda for leveraging meditation research to advance the investigation of psychedelic AEs is recommended. This includes the utility of meditation-related AEs as a comparator condition for psychedelic-related AEs, as well as recommendations for the adoption of (1) detailed and comprehensive, (2) user-informed, (3) impact-based, (4) standardized, (5) unbiased, and (6) representative measures of AEs and (7) examining factors that influence their impacts and trajectories.

Considering distinct positive emotions in psychedelic science

In this review, we discuss psychedelics' acute subjective and persisting therapeutic effects, outline the science of positive emotions, and highlight the value in considering distinct positive emotions in psychedelic science. Psychedelics produce a wide variety of acute subjective effects (i.e. the 'trip'), including positive emotions and affective states such as awe and joy. However, despite a rich literature on distinct emotions and their different correlates and sequelae, distinct emotions in psychedelic science remain understudied. Insofar as psychedelics' acute subjective effects may play a role in their downstream therapeutic effects (e.g. decreased depression, anxiety, and substance misuse), considering the role of distinct positive emotions in psychedelic experiences has the potential to yield more precise statements about psychedelic-related subjective processes and outcomes. We propose here that understanding the role of positive emotions within the context of psychedelic experiences could help elucidate the connection between psychedelics' acute subjective effects and therapeutic outcomes.

The Role of Music in Psychedelic-Assisted Therapy: A Comparative Analysis of Neuroscientific Research, Indigenous Entheogenic Ritual, and Contemporary Care Models

Music is deeply rooted in the human experience as well as a fundamental part of psychedelic-assisted therapies (PAT) and entheogenic ceremonies. Although a large body of research exists highlighting the importance of music from rehabilitative, psychological, neurobiological, anthropological, religious, and sociological contexts, there is limited scientific literature regarding the specific relevance of music in PAT and indigenous entheogenic ritual as a means of enhancing clinical outcomes. As demand for mental health services continues to grow and awareness of the medicinal benefits of psychedelic substances to treat mental and neurological conditions increases, a new wave of interest has emerged to support the development of care models, including how music is used during PAT. Music is a reliable cornerstone in therapeutic and ritualistic spaces using psychedelics, however there is still an immense opportunity to cultivate PAT models with interdisciplinary, evidence-informed perspectives and thoughtful analysis of music use in treatment. To contribute to this development, this review evaluates neuroscientific, psychological, and anthropological research on the neural and cognitive underpinnings of music as well as music use with psychedelics both in modern research settings and indigenous entheogenic ceremonies. In addition, personalized approaches to music protocols in PAT, how music use in traditional rituals may help inform best practices, and the need for researchers to specify music protocols in treatment models are detailed. Consideration of carefully respecting the bridging of indigenous practices and current medical models is discussed to highlight areas for future development.

Exploring the regulatory framework of psychedelics in the US & Europe

Psychedelic drug therapy has gained prominence for its potential in treating various mental health conditions, including depression, post-traumatic stress disorder (PTSD), and anxiety. Psychedelic treatment differs from conventional psychiatric approaches in mode of action, legal status, and treatment approach. This work delves into the therapeutic potential, mechanisms, and regulatory approvals of key psychedelic substances like psilocybin, 3,4-Methyl enedioxy methamphetamine (MDMA), mescaline, ketamine, and Lysergic acid diethylamide (LSD). It also provides an overview of legal aspects, and regulations surrounding psychedelics in the US & Europe, emphasizing their Schedule I classification due to potential misuse. The United States Food & Drug Administration (USFDA) closely monitors psychedelics, employing expedited pathways for evaluation. Further, recent guidance from the FDA on considerations for clinical Investigations supports the safe development of psychedelics for human welfare. European Medicines Agency (EMA) regulators focus on atypical psychedelics, addressing challenges in safety and efficacy. Marketed products, such as Spravato nasal spray, face limited distribution due to safety concerns. The call for careful regulation and legislation is essential for harnessing psychedelics' potential for therapeutic benefits and human welfare.

Narrative review of the potential for psychedelics to treat Prolonged Grief Disorder

Prolonged Grief Disorder (PGD) is distinct from yet related to non-pathologic grief, depression, addiction, and Post-Traumatic Stress Disorder (PTSD) with a prevalence of up to 10% in bereaved populations. Hallmarks of PGD include functional impairment a year or more post-bereavement and intense yearning for the deceased. Current treatments for PGD are typically psychological rather than psychopharmacological, and more treatment options are needed. Psychedelics such as psilocybin and MDMA may be a promising treatment avenue for PGD. Randomized clinical trials demonstrated the efficacy of psilocybin in reducing symptom severity in depression and MDMA in reducing PTSD symptomatology. Furthermore, psychedelics often produce subjective effects (such as transcendence, mystical experiences, and a sense of oneness) that may be uniquely relevant to the existential distress experienced in PGD. No randomized clinical trials have thus far been conducted on the safety and efficacy of psychedelics for PGD. Initial research, including survey-based studies and an open-label trial, has begun to shed light on the possible benefits of psychedelics in the alleviation of grief. While the evidence from these studies is preliminary, it suggests a consistent trend towards the effectiveness of psychedelics in grief reduction. Conducting a randomized clinical trial would be an appropriate next step to explore the potential efficacy of using psychedelics to treat PGD.

Psychedelic research, assisted therapy and the role of the anaesthetist: A review and insights for experimental and clinical practices

Recent years have witnessed an unprecedented increase in the search for the use of psychedelics in improving physical and mental health. Anaesthesia has evolved since very early times, born from the need to eliminate pain and reduce suffering and there are reports of the use of anaesthetics to achieve mystical states since the nineteenth century. Nowadays, the renaissance of psychedelics in anaesthesia has been inspired by their potential in the treatment of chronic pain syndromes, palliative care and in the emergency department and pre-hospital care with the administration of psychedelics in cases of ischaemia, given their potential in neuroprotection. Although there are already some published protocols for the administration of psychedelics in patients with mental illness, little has been addressed concerning non-mental medical applications. In this sense, in patients with multiple comorbidities, functional limitations and polymedicated, the anaesthetist may play a fundamental role, not only in clinical practice, but also in translational research. This article focuses on the description of psychedelics, with a particular focus on dimethyltryptamine (DMT) and ayahuasca pharmacology, effects, safety and toxicity. A detailed description of the role of the anaesthetist in clinical and experimental research is provided, from participant's screening to preparation and dosing session, expected adverse effects and how to manage them, based on the protocol and standard procedures of a current study with neuroimaging during the psychedelic experience. Specific considerations regarding the management of psychedelic toxicity are also provided as well as future directions for safe psychedelic use in clinical practice.

Survey of Massachusetts peer recovery coaches' attitudes toward the use of psychedelics to treat substance use disorders

BACKGROUND

There has been a growing interest in the use of psychedelics for therapeutic purposes. However, there is a lack of research on peer recovery coaches' attitudes toward the use of psychedelics for SUD treatment. Therefore, we conducted a survey of peer recovery coaches in Massachusetts to gain insight into their attitudes toward the use of psychedelics to treat SUDs.

METHODS

Peer recovery coaches in Massachusetts were invited to participate in an online survey between August and October 2023. The survey collected respondents' demographics, socioeconomic characteristics, personal substance use history, opinions on psychedelics for addiction treatment, and spiritual experiences.

RESULTS

146 individuals completed the survey. The mean age was 48.7 years (SD 11.2), 61% identified as female, 74% were employed as peer recovery coaches, and 43% were Certified Addiction Recovery Coaches (CARC). 70.7% reported utilizing 12-step programs, and 76% reported having a personal history of using psychedelics. The majority of participants agreed that they would feel comfortable being a coach for someone using psychedelics to treat SUDs. However, a significant number of participants expressed concerns. Those who had utilized 12-steps were more likely to express concerns about the dangers of using psychedelics to treat SUD. Conversely, participants with a personal history of psychedelic use were more likely to support the use of psychedelics for the treatment of SUDs.

CONCLUSIONS

While peer recovery coaches express support for using psychedelics to treat SUD, they also voice concerns about the potential risks.

Mystical and Affective Aspects of Psychedelic Use in a Naturalistic Setting: A Linguistic Analysis of Online Experience Reports

Analyzing online retrospective experience reports of psychedelic use can provide valuable insight into their acute subjective effects. Such reports are unexplored in relation to mystical states, which are thought to be a therapeutic mechanism within psychedelic-assisted psychotherapy. We created a set of words that, when encountered in an experience report, indicate the occurrence of mystical elements within the experience. We used the Shroomery.org website to retrieve 7317 publicly available retrospective psychedelic experience reports of psychedelic use, primarily of psilocybin, and have a designated experience intensity level self-assessed by the text authors during submission of the report. We counted the mystical language words using Linguistic Inquiry and Word Count (LIWC) software and additionally performed sentiment analysis of all reports. We found that the occurrence of mystical language grew with increased self-reported experience intensity. We also found that negative sentiment increased, and positive sentiment decreased as self-reported psychedelic experience intensity increased. These two findings raise the question of whether mystical experiences can co-exist with challenging elements within the psychedelic experience, a consideration for future qualitative studies. We present a new mystical language dictionary measure for further use and expansion, with some suggestions on how it can be used in future studies.

A Psychometric Evaluation of the Dutch Revised Mystical Experience Questionnaire

In the Netherlands, scientific interest in psychedelics and their subjective effects has been increasing. The present study examined the reliability, construct and predictive validity of the Dutch 30-item Revised Mystical Experience Questionnaire (MEQ30), a self-report measure that has been used to assess subjective and mystical experiences occasioned by psychedelics. In an online survey, 322 Dutch-speaking adults retrospectively reported on profound experiences with psychedelics. Confirmatory factor analyses demonstrated that both a four-factor structure and the same model extended with the MEQ30-total score as a second-order latent variable fit the data. Factor scores showed good internal reliability (α = between .81 and .94) and were significantly higher in participants that beforehand endorsed having had a mystical experience compared to those that did not, providing evidence for the construct validity of the questionnaire as a measure for self-reported mystical experiences. Additionally, MEQ30 scores significantly predicted the meaningfulness and spiritual significance of the psychedelic experience, as well as self-reported positive changes in well-being, life satisfaction and behavior, providing preliminary evidence for the predictive validity of the Dutch MEQ30. Findings suggest the reliability and validity of the Dutch MEQ30 and support the use of the scale in future studies on the subjective effects of psychedelics.

Meta-correlation of the effect of ketamine and psilocybin induced subjective effects on therapeutic outcome

There is some evidence that the subjective effects of ketamine and other psychedelics like psilocybin are crucial for their therapeutic outcomes, such as treatment of depression or substance use disorder (SUD). We performed a meta-analysis and systematic review on the correlation of subjective symptoms and dissociation versus ketamine-induced therapeutic outcomes in patients with depression or SUD. A similar analysis was conducted for psilocybin-induced therapeutic improvement. We retrieved 23 papers studying ketamine (21 on depression, 2 on SUD) in 471 patients and 8 papers studying psilocybin (6 on depression, 2 on SUD) in 183 patients. Our study demonstrated a modest role for subjective effects mediating therapeutic outcomes, with R2-values ranging from 5-10% for ketamine and for psilocybine the R2 was 24%. A greater mediating effect for psilocybin compared to ketamine was detected, particularly when restricting the analysis to depression. Additionally there is a greater mediating effect in SUD than depression, irrespective of treatment.

Unique Transcriptomic Cell Types of the Granular Retrosplenial Cortex are Preserved Across Mice and Rats Despite Dramatic Changes in Key Marker Genes

The granular retrosplenial cortex (RSG) supports key functions ranging from memory consolidation to spatial navigation. The mouse RSG contains several cell types that are remarkably distinct from those found in other cortical regions. This includes the physiologically and transcriptomically unique low rheobase neuron that is the dominant cell-type in RSG layers 2/3 (L2/3 LR), as well as the similarly exclusive pyramidal cells that comprise much of RSG layer 5a (L5a RSG). While the functions of the RSG are extensively studied in both mice and rats, it remains unknown if the transcriptomically unique cell types of the mouse RSG are evolutionarily conserved in rats. Here, we show that mouse and rat RSG not only contain the same cell types, but key subtypes including the L2/3 LR and L5a RSG neurons are amplified in their representations in rats compared to mice. This preservation of cell types in male and female rats happens despite dramatic changes in key cell-type-specific marker genes, with the Scnn1a expression that selectively tags mouse L5a RSG neurons completely absent in rats. Important for Cre-driver line development, we identify alternative, cross-species genes that can be used to selectively target the cell types of the RSG in both mice and rats. Our results show that the unique cell types of the RSG are evolutionarily conserved across millions of years of evolution between mice and rats, but also emphasize stark species-specific differences in marker genes that need to be considered when making cell-type-specific transgenic lines of mice versus rats.

Examining the influence of team-based learning on medical students' comprehension and attitudes regarding psychedelic therapies

INTRODUCTION

This study evaluates the impact of a two-hour team-based learning (TBL) curriculum on medical students' knowledge, comprehension, ethical understanding, and attitudes towards psychedelic therapies.

METHODS

Sixty-three pre-surveys and fifty post-surveys assessed students' perceived knowledge and attitudes using Likert scales. Forty-eight matched pre/post-knowledge tests with multiple-choice questions quantified changes in comprehension. The TBL approach featured independent learning, team readiness assessments, and application exercises.

RESULTS

Post-curriculum, students demonstrated significantly improved test scores (mean 41.4% increase, p < 0.0001) and more positive attitudes across 16 of 18 items (p ≤ 0.0495). Overall attitude scores increased 23% (p < 0.0001). Qualitative feedback reflected enhanced comfort discussing psychedelics clinically. While some students expressed support for psychedelic-assisted therapy, others cited reservations.

DISCUSSION

This innovative curriculum bridged an important education gap given the increasing relevance of psychedelic medicine. Findings suggest TBL enhances medical student preparedness in this emerging field. Continued curricular development is warranted to ensure proper psychedelic education aligns with patient needs and legislative policies. As psychedelic research progresses, maintaining instructional excellence is crucial for future healthcare professionals.

Beyond Psilocybin: Reviewing the Therapeutic Potential of Other Serotonergic Psychedelics in Mental and Substance Use Disorders

There has been a resurgence of interest in the use of psychedelic therapies for several mental and substance use disorders. Psilocybin, a "classic" serotonergic psychedelic, has emerged as one of the primary compounds of interest in clinical research. While research on psilocybin's potential mental health benefits has grown, data on the safety and efficacy of other serotonergic psychedelics remain limited. A comprehensive scoping review on the use of mescaline, ibogaine, ayahuasca, N,N-dimethyltryptamine (DMT), and lysergic acid diethylamide (LSD) in the treatment of mental and substance disorders was conducted. Independent reviewers screened titles, abstracts, and full texts and conducted data extraction. Seventy-seven studies met the inclusion criteria. There were 43 studies of LSD, 24 studies of ayahuasca, 5 studies of DMT, 5 studies of ibogaine, and 5 studies of mescaline. Commonly reported benefits included improved mood and anxiety symptoms, improved insight, reduced substance use, improved relationships, and decreased vegetative symptoms. Commonly reported adverse effects were psychological, neurological, physical, and gastrointestinal in nature. Serious adverse events (homicide and suicide) were reported in published studies of LSD. In conclusion, there is only low-level evidence to support the safety and efficacy of non-psilocybin serotonergic psychedelics in individuals with mental and substance use disorders.

Psychedelic public health: State of the field and implications for equity

BACKGROUND

Psychedelic Public Health is an emerging discipline uniting the practices of public health with the potential benefits of psychedelics to reduce harm and promote health, wellness, and equity at community and population levels. Little is known regarding the current state of psychedelic public health despite rising psychedelic usage, evidence of its health efficacy, opening policy environments, and concerns regarding equity and potential harms.

METHODS

To characterize the current state of psychedelic public health, this survey reviewed relevant webpages from 228 universities housing accredited Schools and Programs in Public Health (SPPHs) and 59 Psychedelic Research Centers (PRCs) in the US and globally. The scan corresponded to the Prisma 2020 checklist, identifying URLs through keyword searches by Beautiful Soup python package and Google search engine web application. Measures were coded through webpage text analysis.

FINDINGS

Fewer than 10% (9.6%) of SPPHs engaged with psychedelics (2.6% substantially), while half (52.6%) of universities engaged (28.1% substantially). Among PRCs, only 10% indicated a collaboration with SPPHs, and fewer than 3% of PRC personnel held public health degrees. PRCs were preponderantly affiliated with medical schools. Although Indigeneity significantly contributes to Western therapeutic psychedelic protocols, only approximately one-quarter of active universities, SPPHs, or PRCs visibly addressed Indigeneity and only one PRC included Indigenous leadership. 92% of PRCs were led or co-led by people characterized as White-European and 88% by men. Only 20-43% of SPPHs, universities, and PRCs visibly addressed social determinants of health.

CONCLUSIONS

Public health schools, which train, study, and advise the future of public health, showed limited involvement in the growing psychedelic field, signifying a gap in psychedelic science and practice. The absence of public health's population-level approaches signifies a missed opportunity to maximize benefits and protect against potential harms of psychedelics at community and population levels.

Psychedelics in Psychiatry, the Nursing Influence, and the Future of Psychedelic Therapies

OBJECTIVE

Psychedelics and psychedelic-assisted therapies (PATs) are on the cusp of becoming medicalized treatment modalities within the United States, both as potential U.S. Food and Drug Administration (FDA)-approved treatment and therapeutic options outside the medical model, through decriminalization efforts within individual states. Bringing with it a paradigm shift in the delivery of health care for both physical and mental health treatment. A workforce of highly trained facilitators will be needed to meet the anticipated demand for this type of treatment and nurses can play a key role in meeting this demand. This article serves to introduce psychedelic-assisted therapies to psychiatric-mental health nurses as we start to see this new field emerge.

METHOD

Review of published literature and other media.

RESULTS

Results based on historical data, modern applications, and future considerations.

CONCLUSIONS

Nurses have been involved with psychedelic-assisted therapies in the past and are fully capable of providing a wide range of roles upon the anticipated approval as a treatment modality.

Breathwork-induced psychedelic experiences modulate neural dynamics

Breathwork is an understudied school of practices involving intentional respiratory modulation to induce an altered state of consciousness (ASC). We simultaneously investigate the phenomenological and neural dynamics of breathwork by combining Temporal Experience Tracing, a quantitative methodology that preserves the temporal dynamics of subjective experience, with low-density portable EEG devices. Fourteen novice participants completed a course of up to 28 breathwork sessions-of 20, 40, or 60 min-in 28 days, yielding a neurophenomenological dataset of 301 breathwork sessions. Using hypothesis-driven and data-driven approaches, we found that "psychedelic-like" subjective experiences were associated with increased neural Lempel-Ziv complexity during breathwork. Exploratory analyses showed that the aperiodic exponent of the power spectral density-but not oscillatory alpha power-yielded similar neurophenomenological associations. Non-linear neural features, like complexity and the aperiodic exponent, neurally map both a multidimensional data-driven composite of positive experiences, and hypothesis-driven aspects of psychedelic-like experience states such as high bliss.

Serine 3.39 and isoleucine 4.60 are key sites for 5-HT2AR-mediated Gs signaling

Certain amino acid sites of 5-HT2AR play crucial roles in interacting with various G proteins. Hallucinogens and non-hallucinogens both act on 5-HT2AR but mediate different pharmacological effects, possibly due to the coupling of different G proteins. Therefore, this study identified the binding sites of hallucinogens and non-hallucinogens with 5-HT2AR through molecular docking. We conducted site mutation to examine the impact of these sites on G proteins, in order to find out the sites that can distinguish the pharmacological effects of hallucinogens and non-hallucinogens. Our results indicate that I4.60A and S3.39A did not affect the ability of hallucinogens to activate Gq signaling, but significantly reduced Gs signaling activation by hallucinogens. These results suggest that S3.39 and I4.60 are important for the activation of Gs signaling by hallucinogens.

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.

[Psilocybin-Assisted Treatment of Depression, Anxiety and Substance use Disorders: Neurobiological Basis and Clinical Application]

Successful therapy of mental disorders is very important in view of the high level of suffering of those affected. Since established pharmaceutical and psychotherapeutic approaches do not lead to the desired improvement in all cases, complementary or alternative treatment methods are intensively researched. Psilocybin-assisted psychotherapy seems particularly promising, and has been approved in the USA for larger clinical trials. Psilocybin belongs to the group of psychedelics and influences psychological experiences. In assisted therapy, psilocybin is administered in controlled doses under medical supervision to patients with different mental disorders. In the studies conducted so far, longer-term positive effects could be shown after just one or a few doses. In order to provide a better understanding of the potential therapeutic mechanisms, this article will first describe neurobiological and psychological effects of psilocybin. To better assess the potential of psilocybin-assisted psychotherapy for various disorders, clinical studies conducted so far with patients administered psilocybin are reviewed.

A Plea for Nuance: Should People with a Family History of Bipolar Disorder Be Excluded from Clinical Trials of Psilocybin Therapy?

Background

As the field of psychedelic therapy grows, it is vital to consider who can safely engage with psilocybin therapy. In most modern clinical trials of psilocybin therapy, individuals with a family history of bipolar disorder (BD) have been excluded from participation because of their genetic predisposition for developing BD.

Review

Case studies and survey data shed light on the risks of psilocybin therapy among those with a family history of BD in the absence of data from modern clinical trials. We review existing evidence that could inform risk stratification for these individuals, including genetic proximity to the affected relative, BD type, age at onset in the relative, and participant age. Hypothesizing that the risk of developing BD may predict the risk of developing serious adverse events when engaging with psilocybin therapy, we propose a risk stratification tool to be utilized when determining the relative risks of psilocybin therapy to those with a family history of BD in the context of clinical trials.

Conclusion

Balancing the need for effective treatments against the potential for serious adverse events in those undergoing psilocybin therapy with a family history of BD, we argue for caution in psychedelic clinical trials but not outright exclusion of these individuals. Our risk stratification tool allows for more nuanced inclusion and exclusion criteria.

Attitudes of European psychiatrists on psychedelics: a qualitative study

Introduction and aim

It is important to understand how mental health practitioners view recent findings on psychedelic-assisted psychotherapy (PAP) as there is potential this treatment may be incorporated into clinical practice. The aim of our study was to explore how psychiatrists who are not involved in psychedelic research and who are located in the European region perceive psychedelics and PAP.

Methods

We conducted online semi-structured interviews with 12 psychiatry specialists and psychiatry trainees from 8 European countries. Data were analyzed using a general inductive approach informed by codebook thematic analysis.

Results

Based on the interviews, we developed four main themes and 14 sub-themes, including (1) Psychedelics hold potential, (2) Psychedelics are dangerous, (3) Future of psychedelics is uncertain, and (4) Psychiatry is ambivalent toward psychedelics.

Discussion

Our respondents-psychiatrists acknowledged the potential of PAP but remained cautious and did not yet perceive its evidence base as robust enough. Education on psychedelics is lacking in medical and psychiatric training and should be improved to facilitate the involvement of mental health experts in decision-making on PAP.

Disentangling the acute subjective effects of classic psychedelics from their enduring therapeutic properties

Recent research with classic psychedelics suggests significant therapeutic potential, particularly for neuropsychiatric disorders. A mediating influence behind symptom resolution is thought to be the personal insight - at times, bordering on the mystical - one acquires during the acute phase of a psychedelic session. Indeed, current clinical trials have found strong correlations between the acute subjective effects (ASE) under the influence of psychedelics and their enduring therapeutic properties. However, with potential barriers to widespread clinical implementation, including the healthcare resource-intensive nature of psychedelic sessions and the exclusion of certain at-risk patient groups, there is an active search to determine whether ASE elimination can be accompanied by the retention of persisting therapeutic benefits of these class of compounds. Recognizing the aberrant underlying neural circuitry that characterizes a range of neuropsychiatric disorders, and that classic psychedelics promote neuroplastic changes that may correct abnormal circuitry, investigators are rushing to design and discover compounds with psychoplastogenic, but not hallucinogenic (i.e., ASE), therapeutic potential. These efforts have paved the discovery of 'non-psychedelic/subjective psychedelics', or compounds that lack hallucinogenic activity but with therapeutic efficacy in preclinical models. This review aims to distill the current evidence - both clinical and preclinical - surrounding the question: can the ASE of classic psychedelics be dissociated from their sustained therapeutic properties? Several plausible clinical scenarios are then proposed to offer clarity on and potentially answer this question.

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.

Personality traits explain the relationship between psychedelic use and less depression in a comparative study

Interest in psychedelics is increasing due to the potential for improved mental health and quality of life. However, adverse effects on mental health are still a concern. Personality traits have been suggested to both influence the psychedelic experience and mental health, and even be changed by psychedelic use. The present study describes for the first time a national sample of Swedish psychedelic users (n = 400) compared to a sex and age-matched control-group of non-users (n = 400) regarding mental health variables (depression, insomnia, problematic alcohol and drug use, and dissociation) and personality (Big Five). Data was collected in an online survey including individuals from 16 years of age who had at least one psychedelic experience. The main results reported psychedelic users as less depressed (Patient Health Questionnaire-9; PHQ-9) (d = - 0.29) and having more use of drugs (Drug Use Disorders Identification Test; DUDIT) (d = 1.27). In the Big Five personality traits, openness differed notably (d = 1.72), and the between-group effects in PHQ-9 were explained by lower neuroticism. Our findings reveal that psychedelic users report less depression and higher drug use, and this is partly due to personality traits. These results have implications on how we view psychedelic users and the use of psychedelic drugs.

Measuring psychotherapeutic processes in the context of psychedelic experiences: Validation of the General Change Mechanisms Questionnaire (GCMQ)

BACKGROUND

Therapeutic and salutogenic effects of psychedelic drugs have been attributed to psychotherapeutic or psychotherapy-like processes that can unfold during the acute psychedelic experience and beyond. Currently, there are no psychometric instruments available to comprehensively assess psychotherapeutic processes (as conceptualized by empirical psychotherapy research) in the context of psychedelic experiences.

AIMS

We report the initial validation of the General Change Mechanisms Questionnaire (GCMQ), a self-report instrument designed to measure five empirically established general change mechanisms (GCMs) of psychotherapy-(1) resource activation, (2) therapeutic relationship, (3) problem actuation, (4) clarification, and (5) mastery-in the context of psychedelic experiences.

METHODS

An online survey in a sample of 1153 English-speaking and 714 German-speaking psychedelic users was conducted to evaluate simultaneously developed English- and German-language versions of the GCMQ.

RESULTS

The theory-based factor structure was confirmed. The five GCMQ scales showed good internal consistency. Evidence for convergent validity with external measures was obtained. Significant associations with different settings and with therapeutic, hedonic, and escapist use motives confirmed the hypothesized context dependence of GCM-related psychedelic experiences. Indicating potential therapeutic effects, the association between cumulative stressful life events and well-being was significantly moderated by resource activation, clarification, and mastery. Factor mixture modeling revealed five distinct profiles of GCM-related psychedelic experiences.

CONCLUSION

Initial testing indicates that the GCMQ is a valid and reliable instrument that can be used in future clinical and nonclinical psychedelic research. The five identified profiles of GCM-related experiences may be relevant to clinical uses of psychedelics and psychedelic harm reduction.

Efficacy and safety of psychedelics for the treatment of mental disorders: A systematic review and meta-analysis

We aim to systematically review and meta-analyze the effectiveness and safety of psychedelics [psilocybin, ayahuasca (active component DMT), LSD and MDMA] in treating symptoms of various mental disorders. Web of Science, Embase, EBSCO, and PubMed were searched up to February 2024 and 126 articles were finally included. Results showed that psilocybin has the largest number of articles on treating mood disorders (N = 28), followed by ayahuasca (N = 7) and LSD (N = 6). Overall, psychedelics have therapeutic effects on mental disorders such as depression and anxiety. Specifically, psilocybin (Hedges' g = -1.49, 95% CI [-1.67, -1.30]) showed the strongest therapeutic effect among four psychedelics, followed by ayahuasca (Hedges' g = -1.34, 95% CI [-1.86, -0.82]), MDMA (Hedges' g = -0.83, 95% CI [-1.33, -0.32]), and LSD (Hedges' g = -0.65, 95% CI [-1.03, -0.27]). A small amount of evidence also supports psychedelics improving tobacco addiction, eating disorders, sleep disorders, borderline personality disorder, obsessive-compulsive disorder, and body dysmorphic disorder. The most common adverse event with psychedelics was headache. Nearly a third of the articles reported that no participants reported lasting adverse effects. Our analyses suggest that psychedelics reduce negative mood, and have potential efficacy in other mental disorders, such as substance-use disorders and PTSD.

The effect of psychedelics on the level of brain-derived neurotrophic factor: A systematic review and meta-analysis

BACKGROUND

Recent interest in the potential therapeutic effects of psychedelics has led to investigations into their influence on molecular signaling pathways within the brain.

AIMS

Integrated review and analysis of different studies in this field.

METHODS

A systematic search was conducted across international databases including Embase, Scopus, Web of Science, and PubMed from inception to 9 July 2023. Eligibility criteria encompassed published and peer-reviewed studies evaluating changes in brain-derived neurotrophic factor (BDNF) levels after psychedelic consumption.

OUTCOMES

A total of nine studies were included in our study. The meta-analysis demonstrated significantly higher BDNF levels in psychedelic consumers compared to healthy controls, with a pooled standardized mean difference of 0.26 (95% CI: 0.10-0.42, I2 = 38.51%, p < 0.001). Leave-one-out analysis indicated robustness in results upon removal of individual psychedelics. No significant publication bias was observed. The results highlight the potential influence of psychedelics on neuroplasticity by altering BDNF levels.

CONCLUSIONS

More precisely, the documented rise in BDNF levels indicates a neurobiological mechanism by which psychedelics could enhance synaptic plasticity and foster the growth of neurons. Given the limited data available on this topic, the conclusions remain uncertain. Consequently, we highly recommend additional research with more extensive sample sizes to yield more reliable evidence in this field.

Psychological flexibility as a mechanism of change in psilocybin-assisted therapy for major depression: results from an exploratory placebo-controlled trial

Several phase II studies have demonstrated that psilocybin-assisted therapy shows therapeutic potential across a spectrum of neuropsychiatric conditions, including major depressive disorder (MDD). However, the mechanisms underlying its often persisting beneficial effects remain unclear. Observational research suggests that improvements in psychological flexibility may mediate therapeutic effects. However, no psychedelic trials to date have substantiated this finding in a clinical sample. In an exploratory placebo-controlled, within-subject, fixed-order study, individuals with moderate to severe MDD were administered placebo (n = 19) followed by psilocybin (0.3 mg/kg) (n = 15) 4 weeks later. Dosing sessions were embedded within a manualized psychotherapy that incorporated principles of Acceptance and Commitment Therapy. Depression severity, psychological flexibility, mindfulness, and values-congruent living were measured over a 16-weeks study period. Psychological flexibility, several facets of mindfulness, and values-congruent living significantly improved following psilocybin and were maintained through week 16. Additionally, improvements in psychological flexibility and experiential acceptance were strongly associated with reductions in depression severity following psilocybin. These findings support the theoretical premise of integrating psilocybin treatment with psychotherapeutic platforms that target psychological flexibility and add to emerging evidence that increasing psychological flexibility may be an important putative mechanism of change in psilocybin-assisted therapy for MDD and potentially, other mental health conditions.

The psychedelic call: analysis of Australian Poisons Information Centre calls associated with classic psychedelics

INTRODUCTION

The global use of certain classical psychedelics has increased in recent years, but little is known about their spectrum of toxicity within Australia. We aim to describe calls to New South Wales Poisons Information Centre relating to exposures to classical psychedelics including lysergic acid diethylamide, psilocybin, N,N-dimethyltryptamine, ayahuasca, mescaline and ibogaine.

METHODS

This is a retrospective observational study of calls to New South Wales Poisons Information Centre between January 2014 and December 2022. We identified exposures to classical psychedelics within New South Wales Poisons Information Centre database and measured the annual number of exposures, source of call (hospital, health care worker, member of the public), co-ingested substances, clinical features and advice given.

RESULTS

There were 737 calls related to relevant psychedelic exposures; 352 (47.8 per cent) to lysergic acid diethylamide, 347 (47.0 per cent) to psilocybin, 28 (3.8 per cent) to N,N-dimethyltryptamine, 4 (0.5 per cent) to ayahuasca, 4 (0.5 per cent) to mescaline and 2 (0.3 per cent) to ibogaine. Cases were predominantly male (77.2 per cent) and aged between 20 and 74 years (65.6 per cent). Psychedelic calls more than doubled from 45 in 2014 to 105 in 2022 and 625 (85 per cent) of all calls were either from or referred to hospital. Co-ingestion of psychedelics with another substance occurred in 249 (33.8 per cent) of calls and the most frequent clinical features related to single substance psychedelic exposures were hallucinations (27.6 per cent), gastrointestinal symptoms (21.7 per cent) and tachycardia (18.1 per cent). Seizures occurred in 2.9 per cent of single substance psychedelic exposures.

DISCUSSION

Increasing incidence of psychedelic exposure calls, including those reporting significant toxicity, likely reflects increasing community use. This may in part be driven by increasing interest in psychedelic assisted psychotherapy trials subsequently increasing public awareness.

CONCLUSION

Relatively high poisoning severity contrasts with safety within clinical trials of psychedelic assisted psychotherapy that may relate to the uncontrolled nature of community use which is mitigated within clinical trial environments. Education about safe use may be useful.

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.