Human hallucinogen research: guidelines for safety

Exploring serotonergic psychedelics as a treatment for personality disorders

Both psychotherapeutic interventions and pharmacological agents have demonstrated limited efficacy in the treatment of personality disorders (PDs). Emerging evidence suggests that psychedelic therapy, already showing promise in treating various psychiatric conditions commonly comorbid with PDs, may exert therapeutic effects by promoting adaptive changes in personality. Thus, psychedelic therapy could hold potential for addressing core features of PDs through shared mechanisms of personality modulation. Although historical literature and observational studies suggest the potential clinical utility of psychedelics in treating PDs, rigorous research is lacking, and individuals with PDs are often excluded from modern psychedelic therapy trials. In the present review, we first discuss research on the effects of psychedelics in individuals with a PD through the conventional lens of the Diagnostic and Statistical Manual of Mental Disorders (5th ed., text rev.; DSM-5-TR) categorical model. Next, using the dimensional DSM Alternative Model of Personality Disorders (DSM-AMPD) as a framework, we examine how psychedelics may affect self-functioning, interpersonal functioning, and pathological personality traits. We conclude by discussing the clinical relevance of psychedelic therapy as a treatment for personality pathology, including safety considerations, gaps and limitations, and recommendations for approaching psychedelic therapy within these more complex clinical populations.

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.

Evaluating the effectiveness of psilocybin in alleviating distress among cancer patients: A systematic review

OBJECTIVES

Psychological and existential distress is prevalent among patients with life-threatening cancer, significantly impacting their quality of life. Psilocybin-assisted therapy has shown promise in alleviating these symptoms. This systematic review aims to synthesize the evidence on the efficacy and safety of psilocybin in reducing cancer-related distress.

METHODS

We searched MEDLINE, APA PsycINFO, Cochrane database, Embase, and Scopus from inception to February 8, 2024, for randomized controlled trials (RCTs), open-label trials, qualitative studies, and single case reports that evaluated psilocybin for cancer-related distress. Data were extracted on study characteristics, participant demographics, psilocybin and psychotherapy intervention, outcome measures, and results. Two authors independently screened, selected, and extracted data from the studies. Cochrane Risk of Bias for RCTs and Methodological Index for Non-Randomized Studies criteria were used to evaluate study quality. This study was registered with PROSPERO (CRD42024511692).

RESULTS

Fourteen studies met the inclusion criteria, comprising three RCTs, five open-label trials, five qualitative studies, and one single case report. Psilocybin therapy consistently showed significant reductions in depression, anxiety, and existential distress, with improvements sustained over several months. Adverse effects were generally mild and transient.

SIGNIFICANCE OF RESULTS

This systematic review highlights the potential of psilocybin-assisted therapy as an effective treatment for reducing psychological and existential distress in cancer patients. Despite promising findings, further large-scale, well-designed RCTs are needed to confirm these results and address existing research gaps.

Rapid and sustained antidepressant effects of vaporized N,N-dimethyltryptamine: a phase 2a clinical trial in treatment-resistant depression

Depression affects over 185 million people worldwide, with approximately one-third classified as treatment-resistant depression (TRD). Current treatments, such as oral antidepressants, often take around 3 weeks to become effective, with no immediate anti-suicidal benefits. The field urgently needs innovative therapies that provide rapid relief. Psychedelics like psilocybin and ayahuasca have shown promising antidepressant effects; however, their long duration (several hours) makes them costly and impractical for public health systems. N,N-Dimethyltryptamine (DMT), an endogenous psychedelic also found in ayahuasca, offers a viable alternative with a short duration of action (10-20 min) and non-invasive inhalation administration. Unlike ayahuasca, which contains monoamine oxidase inhibitors, vaporized DMT acts quickly and poses fewer pharmacological interaction risks. This open-label trial evaluated inhaled DMT for TRD for the first time, within the framework of interventional psychiatry. Fourteen patients (Nfemale = 6) participated in a fixed-order, dose-escalation study (15 mg and 60 mg). The treatment was safe, well-tolerated, and produced manageable psychedelic effects with no serious adverse events. A subpopulation using antidepressants showed similar safety outcomes. Results showed rapid and sustained antidepressant effects, with an average reduction of 21.14 points on the Montgomery-Asberg Depression Rating Scale by day 7 (p < 0.001). The response rate was 85.71%, and the remission rate was 57.14% 7 days post-administration, lasting up to 3 months. Suicidal ideation significantly decreased, with no severe ideation the day after dosing. Vaporized DMT offers a non-invasive, time-efficient, and cost-effective alternative to other psychedelics and traditional antidepressants, supporting its role in interventional psychiatry and public health. Clinicaltrials.gov NCT06094907.

Efficacy and safety of psilocybin for the treatment of substance use disorders: A systematic review

Psilocybin, a serotonergic psychedelic, may have therapeutic benefits for Substance Use Disorders (SUDs), but its overall efficacy and safety remain uncertain. This systematic review assessed the safety and efficacy of psilocybin for SUDs through a systematic database search conducted via OVID on May 22, 2024, and summarized 26 ongoing clinical trials registered on clinicaltrials.gov. Among 16 published included studies, 7 (43.75 %) focused on Alcohol Use Disorder (AUD), 5 (31.25 %) on Tobacco Use Disorder (TUD), and the remainder on Cocaine Use Disorder (CUD) (1, 6.25 %), Opioid Use Disorder (1, 6.25 %), Nicotine Use Disorder (1, 6.25 %), and multiple SUDs (1, 6.25 %). Study designs included open-label trials (5, 31.25 %), cross-sectional observational studies (6, 37.5 %), qualitative analyses (2, 12.5 %), one double-blind RCT (6.25 %), one pilot fMRI study (6.25 %), and one long-term follow-up (6.25 %). Psilocybin-assisted psychotherapy (PAP) was used in 10 studies (62.5 %), with doses ranging from microdosing to 20-40 mg/70 kg. PAP was associated with significant reductions in alcohol consumption, smoking cessation, and related psychological improvements. AUD studies reported fewer heavy drinking days, increased abstinence rates, and neuroimaging data indicating normalization of brain activity. TUD studies demonstrated high smoking abstinence rates, with mystical experiences predicting long-term outcomes. Findings for other SUDs were mixed, though psilocybin showed potential in reducing opioid dependence and nicotine use. Preliminary evidence supports psilocybin's efficacy and safety for AUD and TUD, particularly with psychotherapy, but larger clinical trials are needed to confirm these findings.

Psilocybin-Assisted suppoRtive psychoTherapy IN the treatment of prolonged Grief (PARTING) trial: protocol for an open-label pilot trial for cancer-related bereavement

INTRODUCTION

Prolonged grief disorder (PGD) represents a substantial public health issue, especially in oncology settings where it affects up to 30% of bereaved carers. Current best-practice treatments are lengthy, and up to 50% of participants have persistent PGD. Building on encouraging recent research with psychedelic-assisted therapies, the Psilocybin-Assisted suppoRtive psychoTherapy IN the treatment of prolonged Grief (PARTING) trial is the first study to consider psilocybin-assisted psychotherapy as a potential treatment for prolonged grief.

METHODS AND ANALYSIS

PARTING is an open-label pilot trial of psilocybin-assisted psychotherapy for approximately 15 people with cancer-related PGD. It aims to investigate feasibility, safety, acceptability, participant experience and participant-reported therapeutic effects. Over a 5-week intervention period, participants will undergo three preparation sessions before receiving a psychoactive (25 mg) dose of psilocybin alongside non-directive supportive guidance, followed by four integration sessions. All sessions will be delivered by a psychologist and either a nurse or Indigenous Therapist. An artificial intelligence-assisted tool will be used to create an artwork of participants' psychedelic experience.Outcomes will be investigated over a 12-month follow-up period. Feasibility will be assessed through recruitment/retention rates and completion of follow-up assessments. Safety will be evaluated via adverse events over 12 months and the comparison of physiological measures (vital signs, biochemistry, haematology, ECG) recorded during screening and 1 day after the psilocybin dose. Qualitative thematic analysis of semistructured interviews with participants and trial therapists will assess acceptability and the therapeutic potential of the treatment. Diagnostic clinical interviews for PGD and quantitative participant-reported measures of therapeutic effects are also being collected. Participant-reported measures include grief severity, depression, anxiety, grief avoidance, psychological flexibility, connectedness, and quality of life.

ETHICS AND DISSEMINATION

Ethics approval has been obtained from QIMR Berghofer Medical Research Institute Human Research Ethics Committee (P3801). Dissemination of results will occur via conference presentations, peer-reviewed publications and media.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry (ACTRN12623000827639).

Psilocybin therapy for mood dysfunction in Parkinson's disease: an open-label pilot trial

Mood dysfunction is highly prevalent in Parkinson's disease (PD), a main predictor of functional decline, and difficult to treat-novel interventions are critically needed. Psilocybin shows early promise for treating depression and anxiety, but its potential in PD is unknown, as safety concerns have excluded people with neurodegenerative disease from previous trials. In this open-label pilot (NCT04932434), we examined the feasibility of psilocybin therapy among people with mild to moderate stage PD plus depression and/or anxiety. 12 participants (mean age 63.2 ± 8.2 years, 5 women) received psilocybin (one 10 mg followed by one 25 mg dose) with psychotherapy. There were no serious adverse events, no medical interventions required to manage effects of psilocybin, and no exacerbation of psychosis. Ten participants experienced treatment-emergent adverse events; the most frequent were anxiety, nausea, and increased blood pressure. We observed no worsening of PD symptomology measured by the Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS-UPDRS). On the contrary, non-motor (MDS-UPDRS Part I: -13.8 ± 1.3, p < 0.001, Hedges' g = 3.0) and motor symptoms (Part II: -7.5 ± 0.9, p < 0.001, g = 1.2; Part III: -4.6 ± 1.3, p = 0.001; g = 0.3) as well as performance in select cognitive domains (Paired Associates Learning [-0.44 ± 0.14, p = .003, g = 0.4], Spatial Working Memory [-0.52 ± 0.17, p = 0.003, g = 0.7], and Probabilistic Reversal Learning [2.9 ± 0.9, p = 0.003, g = 1.3]) improved post-treatment, and improvements were sustained until the final safety assessment one month following drug exposure. Baseline Montgomery-Asberg Depression Rating Scale (MADRS) and Hamilton Anxiety Rating Scale (HAM-A) scores were 21.0 ± 8.7 and 17.0 ± 3.7, respectively. Both improved to a clinically meaningful degree post-treatment; these improvements persisted to the final assessment three months following drug exposure (MADRS: -9.3 ± 2.7, p = .001, g = 1.0; HAM-A: -3.8 ± 1.7; p = 0.031, g = 0.7). This study provides the first data on psilocybin's effects in any neurodegenerative disease. Results suggest that psilocybin therapy in PD warrants further investigation.

Longitudinal associations of naturalistic psychedelic use with psychotic and manic symptoms

BACKGROUND

Findings from contemporary clinical trials suggest that psychedelics are generally safe and may be effective in the treatment of various psychiatric disorders. However, less is known about the risks associated with psychedelic use outside of medically supervised contexts, particularly in populations that are typically excluded from participation in clinical trials.

METHODS

Using a preregistered longitudinal observational research design with a purposive sample of US residents between 18 and 50 years old (N=21,990), we investigated associations between self-reported naturalistic psychedelic use and psychotic and manic symptoms, with emphasis on those with psychiatric histories of schizophrenia or bipolar I disorder.

RESULTS

The follow-up survey was completed by 12,345 participants (56% retention), with 505 participants reporting psychedelic use during the 2-month study period. In covariate-adjusted regression models, psychedelic use during the study period was associated with increases in the severity of psychotic and manic symptoms. However, such increases were only observed for those who reported psychedelic use in an illegal context. While increases in the severity of psychotic symptoms appeared to depend on the frequency of use and the intensity of challenging psychedelic experiences, increases in the severity of manic symptoms appeared to be moderated by a personal history of schizophrenia or bipolar I disorder and the subjective experience of insight during a psychedelic experience.

CONCLUSIONS

The findings suggest that naturalistic psychedelic use specifically in illegal contexts may lead to increases in the severity of psychotic and manic symptoms. Such increases may depend on the frequency of use, the acute subjective psychedelic experience, and psychiatric history.

Epigenetic Echoes: Bridging Nature, Nurture, and Healing Across Generations

Trauma can impact individuals within a generation (intragenerational) and future generations (transgenerational) through a complex interplay of biological and environmental factors. This review explores the epigenetic mechanisms that have been correlated with the effects of trauma across generations, including DNA methylation, histone modifications, and non-coding RNAs. These mechanisms can regulate the expression of stress-related genes (such as the glucocorticoid receptor (NR3C1) and FK506 binding protein 5 (FKBP5) gene), linking trauma to biological pathways that may affect long-term stress regulation and health outcomes. Although research using model organisms has elucidated potential epigenetic mechanisms underlying the intergenerational effects of trauma, applying these findings to human populations remains challenging due to confounding variables, methodological limitations, and ethical considerations. This complexity is compounded by difficulties in establishing causality and in disentangling epigenetic influences from shared environmental factors. Emerging therapies, such as psychedelic-assisted treatments and mind-body interventions, offer promising avenues to address both the psychological and potential epigenetic aspects of trauma. However, translating these findings into effective interventions will require interdisciplinary methods and culturally sensitive approaches. Enriched environments, cultural reconnection, and psychosocial interventions have shown the potential to mitigate trauma's impacts within and across generations. By integrating biological, social, and cultural perspectives, this review highlights the critical importance of interdisciplinary frameworks in breaking cycles of trauma, fostering resilience, and advancing comprehensive healing across generations.

Motivation and retrospective appraisal of psychedelic study participation: a qualitative study in healthy volunteers

RATIONALE

Little is known about motives of healthy volunteers to participate in psychedelic trials and how they appraise their study experience retrospectively.

OBJECTIVES

This paper explored reasons why healthy people register for psychedelic trials, factors that they considered to contribute to either positive or negative study experiences, and under which circumstances they would seek a psychedelic experience again.

METHODS

This study used the data of 151 healthy volunteers who had ingested serotonergic psychedelics in one of six randomized, double-blind, placebo-controlled crossover trials at the same research site under similar conditions. The data were analyzed through qualitative content analysis.

RESULTS

The predominant motivations to participate in a trial were interest in psychedelics and an appealing setting. Expectations involved personal development and the occurrence of typical psychedelic effects. Hopes included transformative processes. The setting factors that promoted a positive experience were music and access to nature, whereas the sterile hospital environment was considered bothersome. Most participants valued the trusting relationship with their investigator. The most commonly criticized investigator characteristics were a perceived lack of support and investigator-induced psychological discomfort. Most participants considered their expectations exceeded and would take the study substances again, preferably in a setting in nature with friends.

CONCLUSIONS

This paper identified four pivotal factors to be considered for psychedelic study experiences: (1) a secure interpersonal relationship, (2) an aesthetically pleasing environment, (3) access to nature, and (4) the use of music. This analysis reveals subjective views of volunteers in psychedelic Phase-I trials and may improve research standards.

Concurrent stress modulates the acute and post-acute effects of psilocybin in a sex-dependent manner

There is renewed interest in psychedelics, such as psilocybin, as therapies for multiple difficult-to-treat psychiatric disorders. Even though psychedelics can induce highly pleasant or aversive experiences, depending on multiple personal and environmental factors, there is little research into how such experiences impact post-acute mood-altering actions. Here we aimed at offsetting this gap. First, we tested whether acute psilocybin effects differed between sexes. Adult male and female C57BL/6J mice received saline or psilocybin (5 mg/kg; i.p.), and head-twitch response (HTR) frequency was quantified. Notably, while psilocybin increased HTR frequency in both sexes, the effect was greater in females. We then tested if stress exposure during acute drug effects impacted post-acute psilocybin actions. Following drug treatment, mice were returned to their homecage or restrained for 1 h. Anxiety- and depression-like behaviors were assessed starting 24 h following drug administration, using the marble burying, novelty-suppressed feeding, and splash tests. Psilocybin induced anxiolytic-, but not antidepressant-like, which were fully blocked by stress in males, but only partially so in females. Lastly, we assessed the acute stress-psilocybin interaction on plasma corticosterone levels in a separate cohort of mice, treated as above. Both stress and psilocybin independently increased corticosterone levels, without additive or interactive effects being observed for either sex. Our data reveals the role of sex and peri-acute negative experiences in the acute and post-acute actions of psilocybin. These findings underline the importance of non-pharmacological factors, such as the quality of the psychedelic experience, in the mood-altering effects of psychedelics, holding significant for both their therapeutic and recreational use.

Further education in psychedelic-assisted therapy - experiences from Switzerland

The growing interest in psychedelic-assisted therapy (PAT) for treating psychiatric disorders such as treatment-resistant depression, PTSD, and anxiety has led to an increasing demand for specialized training. In Switzerland, MDMA, psilocybin, and LSD are applied in the framework of limited medical use as exceptional treatment options since 2014. The Swiss Medical Association for Psychedelic Therapy (SÄPT) has been a key player in addressing the need for education, offering a comprehensive, three-year training program for physicians and psychologists. This curriculum integrates theoretical knowledge with hands-on experience, emphasizing the therapeutic relationship, ethical considerations, and the management of altered states of consciousness induced by psychedelics. This article gives an overview of the structure and framework of the training and addresses topics covered by the program through theoretical teaching and retreats focusing on practical learning. However, the demand for these programs far exceeds supply. This gap is expected to widen as psychedelics potentially become regulated prescription medications. In response, several organizations have expanded their educational offerings, including further education trainings, workshops, conferences, and symposia. Overall, there is a need for more comprehensive and accessible training programs to meet the growing demand. The evolving landscape of psychedelic research, regulatory changes, and diverse patient populations require flexible and adaptive training models. As the field progresses, it is essential to establish certification standards and ensure the continued quality of training programs to ensure the safe and effective use of PAT in clinical trials and practice.

An encounter with death: a comparative thematic and content analysis of naturalistic DMT experiences and the near-death experience

Introduction

Classical near-death experiences (NDEs) refer to states of disconnected consciousness characterised by a range of features occurring in the context of being close to death. Various psychedelic substances, such as N,N-dimethyltryptamine (DMT), consistently replicate NDE features and may be considered 'near-death-like experiences.' However, a systematic qualitative analysis comparing the specifics of content with the broader themes of both psychedelic and NDEs has yet to be conducted.

Methods

We report the third thematic and content analysis of the DMT experience from a naturalistic field study, focusing on themes related to death and dying. Based on 36 semi-structured interviews, this analysis is then directly compared, qualitatively and in terms of content frequency, with a novel extension of a previous thematic analysis of 34 written NDE narratives.

Results

The 'canonical NDE themes' identified across the DMT experiences included Translocation, Bright Light(s), Sense of Dying, The Void, Disembodiment, Tunnel-like Structures, Light Being-esque Entities, Deceased Family, Life Review-like, and Hyper-empathic Experiences. A total of 95% of participants reported at least one of these. Twelve 'less typical NDE motifs' were also noted. Five classical NDE features were entirely absent from DMT, while DMT exhibited an even broader array of experience features that were absent from NDEs. DMT clearly shares a more basic phenomenological structure with NDEs but shows differences in the prevalence of certain features. Furthermore, DMT did not present any immediately recognisable linear sequencing of themes. Overall, DMT is distinctly unique in its qualitative content, characterised by its more prodigious and stereotypical nature, which includes kaleidoscopic, extraterrestrial, transcultural, fluctuating, and overwhelming elements.

Discussion

When examining the comparability between DMT and NDEs at a fundamentally more nuanced level of qualitative content (as opposed to broad themes or questionnaire items), the two experiences clearly diverge. However, a minority of NDEs, which are themselves unique, do share significant content with DMT. Taken together, DMT could be considered an 'NDE-mimetic.' The weaker comparability is likely due not only to differences in context but also to the complex neural processes occurring near death, in which endogenous DMT may only play a small role. In light of this level of parallelism with NDEs, some potential clinical applications of DMT are also discussed.

Psychedelic iatrogenic structural dissociation: an exploratory hypothesis on dissociative risks in psychedelic use

This paper introduces the hypothesis of Psychedelic Iatrogenic Structural Dissociation (PISD), proposing that psychedelics may reactivate dissociated traumatic material, increasing the risk of psychological destabilization in trauma-exposed individuals. Grounded in structural dissociation theory, this framework suggests that psychedelics can disrupt the balance between daily functioning (the Apparently Normal Personality, ANP) and trauma-related responses (the Emotional Personality, EP), leading to the resurfacing of unintegrated memories. A review of recent studies highlights persistent adverse effects associated with psychedelic use, including emotional dysregulation, identity fragmentation, derealization, and perceptual disturbances, particularly among individuals with early trauma histories. To mitigate these risks and facilitate trauma processing, integration practices, body-focused therapies, and structured social support systems are proposed as key interventions. Additionally, emerging neurophysiological models suggest that psychedelics may reconfigure dissociative processes through the modulation of entrenched patterns, potentially facilitating trauma integration or increasing vulnerability to destabilization, depending on individual and contextual factors. These findings underscore the necessity of trauma-informed screening, preparation, and integration protocols to enhance the safety and efficacy of psychedelic therapies, particularly for vulnerable populations.

The Hallucinogen Rating Scale: Updated Factor Structure in a Large, Multistudy Sample

Background

The Hallucinogen Rating Scale (HRS) has been widely used to measure the subjective effects of psychedelics and other psychoactive substances. Its advantages include a basis in phenomenological interviews and clinical studies, straightforward items, and broad coverage of psychedelic effects. Previous studies have attempted to resolve its factor structure but were limited by small samples of participants who took only one substance.

Methods

We obtained 991 HRS questionnaires from the authors of 18 publications involving 13 psychoactive substances. Exploratory factor analysis was used to analyze its factor structure, and mixed-effects analyses of variance were used to compare HRS scores between drugs.

Results

The HRS resolved into 8 factors with good to excellent internal consistency and that intuitively map onto the effects of psychedelics. The factor model also showed good measures of fit that were superior to previous proposed models. Model factors were able to show dose responses for most drugs. Additionally, patterns of responses on the 8 factors significantly differentiated classic psychedelics, such as psilocybin and DMT, from other substance classes, including dissociatives such as ketamine and salvinorin A, empathogens such as MDMA, stimulants such as methylphenidate and amphetamine, and Δ9-tetrahydrocannabinol. The factor of meaningfulness also uniquely differentiated psychedelics from all other substances.

Conclusions

These data show that the HRS is an intuitive and psychometrically sound tool for measuring the effects of psychedelic drugs, and it may also have utility for measuring the effects of other drugs and altered states of consciousness.

Psychedelics for Cancer Pain and Associated Psychological Distress: A Narrative Review of a Potential Strategy

PURPOSE

To evaluate the current level of evidence for the use of psychedelics for the management of cancer pain and associated psychological distress.

CONTENT

Pain is a common symptom of cancer and treatment. However, there are high rates of undertreatment of cancer pain due to the complex underlying biology of the condition, and potentially due to a decrease in opioid prescribing in response to the opioid epidemic. A diagnosis of cancer and cancer-related pain can trigger high levels of psychological distress throughout cancer treatment. Cancer pain can also be exacerbated by anxiety, depression, quality of life challenges, and fear of death and dying, as well as by fear of recurrence or progression. Several pharmacologic and non-pharmacologic approaches have been utilized to mitigate pain and symptom burden with some success. However, there remains an unmet need for better management of cancer pain and associated symptoms. Psychedelics, such as lysergic acid diethylamide (LSD), psilocybin, mescaline, and N,N-dimethyltryptamine (DMT), are under consideration as new pharmacologic strategies for mitigating pain and the distress associated with cancer pain and associated symptom burden. Although published studies are limited, regulatory hurdles have decreased. Many clinical trials are underway to assess further the use of psychedelics and behavioral counseling for patients with cancer and comorbidities such as anxiety or depression. These studies examine both the feasibility and efficacy of psychedelics for pain and psychological distress. Early results are promising, and additional research is needed to understand efficacy and tolerability in broader cancer populations.

IMPLICATIONS

There is an unmet need to improve pain management in patients with cancer and to mitigate psychological distress. Further research is required to understand the efficacy of psychedelics for the treatment of cancer pain and distress. Recent regulatory changes have paved the way for increased research on the clinical efficacy of psychedelics in cancer.

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.

The ketamine chameleon: history, pharmacology, and the contested value of experience

INTRODUCTION

Since its synthesis in 1962, ketamine has been widely used in diverse medical contexts, from anesthesia to treatment-resistant depression. However, interpretations of ketamine's subjective effects remain polarized. Biomedical frameworks typically construe the drug's experiential effects as dissociative or psychotomimetic, while psychedelic paradigms emphasize the potential therapeutic merits of these non-ordinary states.

AREAS COVERED

Ketamine's psychoactive effects have inspired diverse interpretations. In this review, we trace the historical evolution of these perspectives - which we broadly categorize as 'dissociative,' 'dream-like,' and 'psychedelic' - and show how they emerged out of these clinical contexts. We highlight the influence of factors such as language, dose, and environmental context on ketamine's effects and therapeutic outcomes. We discuss potential mechanisms underlying these context-dependent effects and explore the broader clinical and research-related ramifications.

EXPERT OPINION

Ketamine's subjective effects are undeniably powerful, yet their therapeutic significance remains debated. A nuanced, interdisciplinary approach is essential for maximizing ketamine's potential. Future research should focus on how explanatory models, treatment environments, and patient preparation can optimize ketamine's benefits while minimizing distress. We suggest that, rather than being a tiger to be tamed as its creator once described, ketamine may best be understood as a chameleon whose color shifts depending on its context.

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.

Single-dose psilocybin therapy for alcohol use disorder: Pharmacokinetics, feasibility, safety and efficacy in an open-label study

BACKGROUND

Psilocybin, a serotonin 2A receptor agonist with psychedelic properties, shows promise as a novel treatment for alcohol use disorder (AUD). While current studies involve two dosing sessions, the effects of a single dose have not been investigated.

AIMS

To investigate the pharmacokinetics, feasibility, safety and efficacy of single-dose psilocybin therapy in AUD.

METHODS

This open-label, single-group study investigated single-dose psilocybin therapy in 10 treatment-seeking adults (8 men and 2 women; median age 44 years) with severe AUD. The treatment involved two preparation sessions, a high-dose psilocybin session (25 mg) and two integration sessions. Pharmacokinetics were determined by noncompartmental analysis, and changes in alcohol consumption, craving and self-efficacy, were assessed using a linear mixed model.

RESULTS

Notable between-participant pharmacokinetic variations were observed, with peak plasma psilocin concentrations ranging from 14 to 59 µg/L. Alcohol consumption significantly decreased over the 12 weeks following psilocybin administration. Heavy drinking days were reduced by 37.5 percentage points (95% CI: -61.1 to -13.9, p = 0.005), and drinks per day decreased by 3.4 drinks (95% CI: -6.5 to -0.3, p = 0.03). This was corroborated by reports of rapid and sustained reductions in craving and increases in self-efficacy.

CONCLUSIONS

Despite pharmacokinetic variations, a single 25 mg psilocybin dose was safe and effective in reducing alcohol consumption in AUD patients. Larger randomised, placebo-controlled, single-dose AUD trials are warranted.

CLINICAL TRIAL REGISTRATION

https://clinicaltrials.gov/study/NCT04718792.

Evaluating the value and risks of psychedelics for psychiatric medicine: a clinical perspective

INTRODUCTION

After a long period of obscurantism, a possible role of psychedelics in clinical practice has progressively become a tangible perspective during the last two decades. However, the resounding enthusiasm linked to such 'psychedelic renaissance' runs the risk to unduly minimize the possible hazards associated with these compounds, while expanding their alleged benefits to improbable panacea-like proportions. In order to avoid mystifying or demonizing the properties of 5-HT2a agonists on emotional grounds, this subject requires a strictly unprejudiced and cautious approach to the evidence.

AREAS COVERED

In this article, the authors attempted to comprehensively analyze the available literature to provide a balanced overview of the possible benefits of psychedelics in healthcare, taking into account their potential risks.

EXPERT OPINION

To date, psychedelics have shown a therapeutic potential in a wide range of conditions, with a seemingly limited risk of inducing adverse reactions, including abuse and dependence, when administered in a controlled environment by specialized personnel. In any case, although several questions remain unanswered before drawing firm conclusions, further studies are needed to establish which conditions and subjects could benefit from psychedelics and which patients bear the greater risk of adversities.

Psychedelics and schizophrenia: a double-edged sword

Psychedelics have shown promising effects in several psychiatric diseases as demonstrated by multiple clinical trials. However, no clinical experiments on patients with schizophrenia have been conducted up to date, except for some old semi-anecdotal studies mainly performed in the time-span '50s-'60s. Notably, these studies reported interesting findings, particularly on the improvement of negative symptoms and social cognition. With no doubts the lack of modern clinical studies is due to the psychomimetic properties of psychedelics, a noteworthy downside that could worsen positive symptoms. However, a rapidly increasing body of evidence has suggested that the mechanisms of action of such compounds partially overlaps with the pathogenic underpinnings of schizophrenia but in an opposite way. These findings suggest that, despite being a controversial issue, the use of psychedelics in the treatment of schizophrenia would be based on a strong biological rationale. Therefore, the aim of our perspective paper is to provide a background on the old experiments with psychedelics performed on patients with schizophrenia, interpreting them in the light of recent molecular findings on their ability to induce neuroplasticity and modulate connectivity, the immune and TAARs systems, neurotransmitters, and neurotropic factors. No systematic approach was adopted in reviewing the evidence given the difficulty to retrieve and interpret old findings. Interestingly, we identified a therapeutic potential of psychedelics in schizophrenia adopting a critical point of view, particularly on negative symptoms and social cognition, and we summarized all the relevant findings. We also identified an eligible subpopulation of chronic patients predominantly burdened by negative symptoms, outlining possible therapeutic strategies which encompass very low doses of psychedelics (microdosing), carefully considering safety and feasibility, to pave the way to future clinical trials.

Cardiovascular effects and safety of classic psychedelics

Psychedelics, used for millennia in spiritual and healing practices, have emerged as promising treatments for mental health conditions including depression, post-traumatic stress disorder (PTSD), substance use disorders and anxiety. Despite the therapeutic potential of psychedelics and their increasing use in both medical and nonmedical settings, there is a paucity of data on their cardiovascular safety. Here we review current evidence on the cardiovascular effects and safety of this unique class of therapeutic agents. The cardiovascular effects and associated risks of classic psychedelics are categorized into three areas: electrophysiological effects and arrhythmia risk, structural effects and valvular heart disease risk, and vascular effects including hypertension and ischemia risks. The Review also emphasizes crucial knowledge gaps that require further basic and clinical investigation including studies in individuals with underlying cardiovascular disease, characterization of important drug-drug interactions and studies on the safety of repetitive, long-term (including microdosing) exposure to classic psychedelics.

Perceived changes in mental health and social engagement attributed to a single psychedelic experience in autistic adults: results from an online survey

RATIONALE

Anecdotal reports suggest that psychedelic drugs can improve psychological wellbeing and social engagement in autistic people. However, there are few contemporary studies on this topic.

OBJECTIVES

To examine autistic participants' experiences with psychedelic drugs and the extent to which they attributed changes in mental health and social engagement to their most 'impactful' psychedelic experience. We also explored associations between these changes and mechanistically important variables (e.g., aspects of the acute psychedelic experience and changes in 'psychological flexibility').

METHODS

Self-selecting autistic participants (n = 233) with high autism quotient scores completed an online survey relating to their most impactful psychedelic experience. Questionnaires assessed the acute psychedelic experience and perceived psychedelic-induced changes in distress, social engagement and psychological flexibility, among other relevant variables.

RESULTS

The majority of participants attributed reductions in psychological distress (82%) and social anxiety (78%) and increases in social engagement (70%) to their most 'impactful' psychedelic experience. A substantial minority (20%) also reported undesirable effects such as increases in anxiety with some describing their psychedelic experience as among the most negatively impactful experiences of their lives. The only substantial predictor of reductions in psychological distress was increased psychological flexibility.

CONCLUSION

Autistic people attributed changes in mental health and social engagement to a single highly impactful psychedelic experience. The results and their implications are discussed with caution considering the use of a non-experimental design and biased sampling.

From relaxed beliefs under psychedelics (REBUS) to revised beliefs after psychedelics (REBAS)

The Relaxed Beliefs Under pSychedelics (REBUS) model proposes that serotonergic psychedelics decrease the precision weighting of neurobiologically-encoded beliefs. We conducted a preliminary examination of two psychological assumptions of REBUS: (a) psychedelics foster acute relaxation and post-acute revision of confidence in mental-health-relevant beliefs; which (b) facilitate positive therapeutic outcomes and are associated with the entropy of EEG signals. Healthy individuals (N = 11) were administered 1 mg and 25 mg psilocybin 4-weeks apart. Confidence ratings for personally held beliefs were obtained before, during, and 4-weeks post-psilocybin. Acute entropy and subjective experiences were measured, as was well-being (before and 4-weeks post-psilocybin). Confidence in negative self-beliefs decreased following 25 mg psilocybin. Entropy and subjective effects under 25 mg psilocybin correlated with decreases in negative self-belief confidence (acutely and at 4-weeks). Particularly strong evidence was seen for a relationship between decreases in negative self-belief confidence and increases in well-being. We report the first empirical evidence that the relaxation and revision of negative self-belief confidence mediates psilocybin's positive psychological outcomes, and provide tentative evidence for a neuronal mechanism, namely, increased neuronal entropy. Replication within larger and clinical samples is necessary. We also introduce a new measure for examining the robustness of these preliminary findings and the utility of the REBUS model.

Down the Rabbit Hole: A Large-Scale Survey of Psychedelic Users' Patterns of Use and Perceived Effects

The ever-changing landscape surrounding legality and accessibility of psychedelics and their increasing popularity make it imperative to better understand the nature of psychedelic use by the general population. To this end, 1,486 eligible respondents (Mage = 29.58, 67.1% male) residing in the United States completed an online survey designed to assess the types of psychedelics used, methods of administration and dosing, frequency of use, intentions for use, context/environments in which they are used, perceived acute effects, frequency of those effects and distress about them, and their perceived residual effects and distress about them. Respondents predominantly endorsed using MDMA, LSD, DMT, and psilocybin. The predominant methods of administration were oral. Most reported using psychedelics for recreational purposes. The most endorsed acute effects were hallucinations, increased heart rate, positive mood, and visual tracers, while the most endorsed residual effects were headaches/migraine, dry mouth, nausea, hallucinations, and anxiety. Participants were most distressed by negative mood states, vomiting, and nausea when under the acute effects of psychedelics, but mean distress ratings were low. These results can help inform clinical trials, reform policy regarding legal access to psychedelics, and track changes in these metrics as sociocultural and legal landscapes continue to shift.

Exploring the Potential of Psychedelics in the Treatment of Headache Disorders: Clinical Considerations and Exploratory Insights

PURPOSE OF REVIEW

Exploration of the potential of serotonergic psychedelic drugs, such as psilocybin and LSD, as potential treatments for headache disorders. This review addresses the need for well-informed physician guidelines and discusses mechanisms, safety, and efficacy of these treatments. Further research, including the consideration of combination with psychotherapy, is needed.

RECENT FINDINGS

Psychedelics demonstrate promising outcomes as treatments for headache disorders. Recent findings indicated that some patients who underwent brief periods of treatment with psychedelics experienced a reduction in headache attack frequency, severity, or duration. When prescription medications are ineffective at treating headache disorders, or are habit-forming, patients often turn to alternative options. There is anecdotal evidence that psychedelic drugs like LSD and psilocybin can effectively treat and prevent pain in patients with headache disorders, such as migraine or cluster headache. It is vital that physicians treating patients who self-treat with psychedelics be well-informed about the mechanisms and their effects to best advise their patients and coordinate their care well. This is a review assessing the literature on the mechanisms, safety, and efficacy of psychedelic drugs as a headache management intervention. We believe there is evidence that may support further investigation into the clinical use of psychedelic medications to treat cluster headache and migraine, including the consideration of use in conjunction with other interventions like cognitive behavioral therapy or acceptance and commitment training.

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.

A systematic review of participant diversity in psychedelic-assisted psychotherapy trials

A lack of diverse and representative participant samples in mental health intervention research perpetuates mental health disparities. This issue has become a salient concern in studies of psychedelic-assisted psychotherapy (PAT), which is emerging as a promising mental health intervention. This systematic review evaluates the reporting, representation, and analysis of participant sociodemographic characteristics in randomized controlled trials (RCTs) of PAT. A total of 21 RCTs of psilocybin- and 3,4-methylenedioxy methamphetamine (MDMA)-assisted therapies (N = 1034) are summarized. Participants' gender (100%) and race or ethnicity (76%) were frequently reported, with socioeconomic status (SES) sometimes (57%) reported using heterogeneous metrics. Sexual orientation (9.5%) and immigration status (4.8%) were rarely reported, and no studies reported gender identity. Compared to their representation in the US population and non-psychedelic clinical trials, Black/African-American participants (2.2%) and Hispanic/Latino participants (7.2%) were significantly underrepresented in PAT RCTs. MDMA trials enrolled more diverse participant samples than psilocybin trials. Analyses on treatment effects based on demographic variables were virtually nonexistent. These findings underscore the need for more inclusive recruitment strategies, along with more rigorous reporting, to improve the generalizability of PAT research.

Psychedelic-related deaths in England, Wales and Northern Ireland (1997-2022)

BACKGROUND

Psychedelic drugs are increasingly visible in society once more, but their risks and adverse effects have received less attention than perhaps they should. While fatalities associated with psychedelics appear rare, a systematic approach to characterising their aetiology is required to inform harm minimisation efforts.

AIMS

This study aimed to analyse prevalence and characteristics of psychedelic-related deaths in England, Wales, and Northern Ireland, between 1997 and 2022.

METHODS

We analysed coroner reports submitted to the National Programme on Substance Use Mortality where psychedelic serotonergic agonist drugs were involved in the death, and conducted a thematic framework analysis to explore potential factors associated with their occurrence.

RESULTS

We identified 28 cases where psychedelics were implicated (75 %, N = 21) or potentially implicated (25 %, N = 7) in the death; 19 of these involving psychedelic tryptamines (LSD 39 %, N = 11; Psilocybin 21 %, N = 6; DMT 7 %, N = 2), and 9 psychedelic phenethylamines (incl. NBOMes 18 %, N = 5). Most deaths were deemed accidental by the coroner (86 %, N = 24), including both traumatic injuries and drug toxicities; most cases involved multiple implicated drugs (68 %, N = 19); and most of the deceased were under 30 years of age (82 %, N = 23). Thematic framework analysis identified nine themes in the deaths across three categories. 'Polysubstance use' was the most common theme (82 % of cases, N = 23/28), followed by a suboptimal 'physical environment' (70 % of cases where this information was available, N = 14/20).

CONCLUSIONS

The profound and often unpredictable effects of psychedelics pose a unique profile of risks and adverse reactions. Nevertheless, psychedelic-related deaths remain very rare in comparison to other recreational drugs, and frequently involve polydrug use. Implications for harm reduction and policy are discussed.

Ayahuasca-assisted meaning reconstruction therapy for grief: a non-randomized clinical trial protocol

Background

Psychotherapy for Prolonged Grief Disorder (PGD), a condition characterized by an intense and persistent grief response, has received increased attention over the past decades. Evidence-based approaches to prevent PGD are currently scarce, and not always effective. This paper introduces a protocol for a clinical trial exploring the effectiveness of a Meaning Reconstruction psychotherapy approach (MR) assisted with ayahuasca, a traditional indigenous medicine.

Method

The outlined protocol is a three-arm, non-randomized controlled trial focused on reducing normal and pathological grief symptoms, comparing the effectiveness of Ayahuasca-assisted MR therapy (A-MR), MR therapy alone (MR) and No Treatment (NT). At least 69 people who lost a first-degree relative during the prior year, and with a Texas Revised Inventory of Grief score up 39 (TRIG ≥ 40), will participate in the trial. Participants will be allocated to an A-MR (n ≥ 23), MR (n ≥ 23) or NT (n ≥ 23) group. Those from the A-MR and MR therapy groups will undergo a therapeutic process involving 9 sessions of online psychotherapy. In addition, the A-MR condition involves 2 group sessions of ayahuasca. The primary outcomes will be normal and pathological grief severity as measured by the TRIG and Traumatic Grief Inventory Self-Report (TGI-SR), administered at baseline, post-treatment, and 3-month follow up. Measures of quality of life, post-traumatic growth, meaning-made, psychological flexibility, and self-belief consistency will be also included. In addition, subjective effects of ayahuasca and acceptance-avoidance promoting effects will be assessed following ayahuasca administration. Finally, we will analyze the potential mediating effect of meaning-made, psychological flexibility and self-belief consistency in grief symptoms (as measured by the TRIG and TGI).

Discussion

This trial is the first to empirically examinate the potential of psychedelic-assisted psychotherapy for grief, as well as the potential processes of change that may account for it.

Clinical trial registration

https://clinicaltrials.gov, identifier NCT06150859.

Pain and Perception: Exploring Psychedelics as Novel Therapeutic Agents in Chronic Pain Management

PURPOSE OF REVIEW

Chronic pain affects approximately 1.5 billion people worldwide, representing the leading cause of disability and a significant financial burden on healthcare systems. Conventional treatments, such as opioids and non-steroidal anti-inflammatory drugs, are frequently linked to adverse effects, including dependency and gastrointestinal issues, and often offer limited long-term relief. This review explores the potential of psychedelics, including psilocybin, LSD, and ketamine, as alternative therapeutic agents in chronic pain management.

RECENT FINDINGS

These substances modulate pain perception through actions on serotonergic and glutamatergic systems and may promote neuroplasticity, offering novel pathways for pain relief. Specifically, the review details the pharmacologic actions of psychedelics, their effects on chronic pain syndromes such as cancer pain, migraines, and neuropathic pain, and their clinical implications. The safety profiles, patient responses, and analgesic properties of these compounds are examined, highlighting the need for further research to validate their efficacy and optimize their therapeutic use in pain management.

Therapeutic Potential of Psychedelic Drugs: Navigating High Hopes, Strong Claims, Weak Evidence, and Big Money

Therapeutic claims about many psychedelic drugs have not been evaluated in any studies of even modest rigor. The science of psychedelic drugs is strengthening, however, making it easier to differentiate some promising findings amid the hype that suffuses this research area. Ketamine has risks of adverse side effects (e.g., addiction and cystitis), but multiple studies suggest it can benefit individuals with treatment-resistant depression. Other therapeutic signals from psychedelic drug research that merit rigorous replication studies include 3,4-Methylenedioxymethamphetamine (MDMA) for post-traumatic stress disorder (PTSD) and psilocybin for depression, end of life dysphoria, and alcohol use disorder. The precise mechanisms through which psychedelic drugs can produce benefit and harm are not fully understood. Rigorous research is the best path forward for evaluating the therapeutic potential and mechanisms of psychedelic drugs. Policies governing the clinical use of these drugs should be informed by evidence and prioritize the protection of public health over the profit motive.

Primum Non Nocere: The Onus to Characterize the Potential Harms of Psychedelic Treatment

The last few years have seen exponential growth in interest, investment, advocacy, and research into psychedelics as therapeutics. This reflects an optimism about the potential promise of psychedelics as therapeutics. As with all therapeutic interventions, research is needed not only into their benefits but also potential risks. Indeed, when substances with therapeutic potential are scrutinized over time, especially in broad populations with psychiatric and medical comorbidities typically excluded from clinical trials, and applied in less well-regulated or controlled settings, a greater understanding of the cautions emerges. Here, we review the literature on the known and potential harms, including enduring perceptual disturbances; triggering or enhancing the risk for onset of mania or psychosis; overuse, misuse, and dependence; challenging experiences or "bad trips"; risks associated with increased neuroplastic potential; and acute and cumulative cardiovascular effects. Each of these issues is addressed in this review, along with the call for continued research, including recommendations for further research and monitoring.

Benefits and Challenges of Ultra-Fast, Short-Acting Psychedelics in the Treatment of Depression

Unlike classical antidepressants, psychedelics such as psilocybin have been shown to induce a rapid antidepressant response. In the wake of this development, interest has emerged in ultra-fast, short-acting psychedelics such as 5-methoxy-N,N-dimethyltryptamine (5-MeO-DMT) and N,N-dimethyltryptamine (DMT) with the expectation that these can produce rapid antidepressant effects following an intense but brief psychedelic intervention. The current paper reviews the clinical pharmacology of 5-MeO-DMT and DMT and their potential benefits and challenges in the treatment of depression. Both compounds display affinities for a variety of monoamine receptors and transporters, but mostly so for serotonergic (5HT) receptors, including 5HT1A and 5HT2A. Early clinical trials in small samples have shown that short interventions (15-30 min) with 5-MeO-DMT and DMT are safe and well tolerated and can induce marked improvement in symptoms of depression within 24 hours that sustain for at least 1 week. Data on long-term efficacy are currently scarce but do suggest a prolongation of the treatment response. Potential benefits of these treatments include flexible, single day dosing regimens, achievement of treatment efficacy independent from integrative therapy, and ease of clinical implementation. Future challenges include establishing the duration of the antidepressant effect and strategies on how to sustain the antidepressant response, optimization of treatment delivery parameters, and a mechanistic understanding of the clinical response. Acceptance of ultra-fast, short-acting psychedelics will depend on future randomized, placebo-controlled trials with a focus on replication, duration and maintenance of antidepressant efficacy in large patient samples.

Practical considerations in the establishment of psychedelic research programs

RATIONALE

There is increasing interest in establishing psychedelic research programs at academic medical centers. However, psychedelics are intensely psychoactive, carry considerable sociopolitical baggage, and most are Schedule I drugs, creating significant potential impediments to implementation. There is little formal guidance for investigators on navigating the complex on-the-ground obstacles associated with establishing psychedelic research programs.

OBJECTIVES

This article provides recommendations that may be helpful to investigators seeking to work with psychedelics, with a focus on academic medical centers in the United States.

METHODS

The academic literature on relevant matters is reviewed, and the authors provide observations from their experiences either working for relevant regulatory agencies or conducting basic science studies, investigator-initiated trials, or industry sponsored trials with psychedelics.

RESULTS

Investigators planning to conduct psychedelic research should cultivate broad institutional support early. Challenges related to securing funding, obtaining approval for an Investigational New Drug application from the Food and Drug Administration, clinical grade drug sourcing, obtaining a Schedule I researcher registration from the Drug Enforcement Administration and an equivalent state license (if required), preparing spaces for treatment and study drug storage, managing controlled substance inventory, engaging the local community, and other issues should be anticipated.

CONCLUSIONS

Investigators should anticipate several implementation challenges when planning to work with psychedelics. However, these are likely surmountable with planning, persistence, and assistance from colleagues and other experts.

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.

Exploring Psychedelics Pharmacology: A Scoping Review Charting the Course of Psilocybin Pharmacokinetics

OBJECTIVES

This scoping review aimed to synthesize the existing data about psilocybin pharmacokinetics to learn what has been described regarding body disposition and safety when psilocybin was used in controlled research settings.

METHODS

We performed a scoping literature review following the framework proposed by the JBI manual for evidence synthesis. Controlled clinical trials reporting pharmacokinetic data of psilocybin were considered appropriate for inclusion. We extracted the data on psilocybin pharmacokinetics and summarized it from the available literature on this topic. We also performed an exploratory-descriptive analysis using study level data to examine the relationship between dose of psilocybin and maximum serum concentrations (Cmax).

RESULTS

We initially identified 850 articles, of which 5 were included. These trials included 112 healthy volunteers who received psilocybin in a controlled clinical setting. The peak concentration of psilocin in plasma (Cmax) ranged from 8.2 ng/mL to 37.2 ng/mL (median = 17, IQR = 11.9 to 23.5). The maximal concentrations (Cmax) of psilocin were reached (Tmax) around 2 hours, ranging from 1.7 hours to 2.2 hours (median = 2, IQR = 1.9 to 2.1) after psilocybin oral administration. Elimination half-life was between 1.2 hours and 3.3 hours (median = 2.0, IQR = 1.6 to 2.8). A strong positive relationship between dose and Cmax ( R2 = 0.95) was found. No serious adverse events were observed. We did not find studies reporting pharmacokinetic data from patients with depression or cancer patients transitioning to palliative care.

CONCLUSIONS

In summary, this review unveils oral psilocybin pharmacokinetics in healthy adults, revealing gaps in its application to target populations like those with depression or in palliative care.

Compass Psychological Support Model for COMP360 Psilocybin Treatment of Serious Mental Health Conditions

The psychedelic experience can be challenging. There is a need for a structured framework for providing psychological support to individuals with mental health conditions receiving investigational psilocybin treatment. The primary benefit of such a framework is to support a safe and meaningful psilocybin experience. It also enables future research on the facets of psychological support and/or psychotherapy that most optimally complement psilocybin treatment. The authors describe the Compass Psychological Support Model (CPSM), currently used to support participants with treatment-resistant depression in Compass-sponsored clinical trials of investigational COMP360 psilocybin treatment. The authors also outline the therapist training, mentoring, and fidelity assessment programs they have developed to ensure the quality and consistency of the CPSM delivery.

Informed Consent in Psychedelic-Assisted Therapy

Humans have long used classical serotonergic psychedelics, such as psilocybin, for a variety of purposes. Entactogens, such as methylenedioxymethamphetamine (MDMA), emerged during the twentieth century and have likewise seen use in a broad range of settings. Interest has arisen in the use of classical psychedelics and entactogens, together termed "psychedelics," for therapeutic purposes in Western clinical settings. Care in these settings is governed by standards for the communication and assumption of risk in the process of informed consent. Rigorous informed consent standards in psychedelic medicine are not only essential for quality care but also critical to the mitigation of risk, particularly in research settings and for vulnerable individuals. This chapter describes practical elements of informed consent in psychedelic therapy, with a focus on effective communication of the risks and potential benefits of classical psychedelic and entactogen treatments as they are currently understood.

Phenomenology of Psychedelic Experiences and Psychedelic-Associated Distressing Effects: Quantifying Subjective Experiences

The range of phenomena that can be induced by psychedelic substances is broad and variable, including effects on perception, cognition, and emotion. The umbrella term "psychedelic phenomenology" is used to refer to a combination of altered experiential features, such as hallucinations or ego dissolution, which together constitute a psychedelic experience. However, there is no consensus on the set of alterations of consciousness that qualifies an altered state to be a "psychedelic state." In this chapter we summarize the most commonly discussed changes in subjective experiences which could be seen as "core features" of psychedelic experiences. While acknowledging the rich history of pioneering phenomenological work of the last century, this chapter focuses on more recent developments in the quantitative work on the assessment of these phenomena. We also address the under-researched phenomenology of distressing effects, often referred to as "challenging experiences" or "bad trips," and point to their importance in understanding the therapeutic potential and risks associated with psychedelic phenomenology. Historically, one can find many links between psychedelic phenomenology and the phenomenology of psychopathology. We stress the importance to refine the assessment and description also of distressing effects, to identify factors that promote acute experiences which are beneficial and limit those which can have potentially harmful long-term effects.

Psychedelic Therapeutics for Adolescents: Ethics, Safety, Opportunities, and Equipoise-Authors' Reply

We are writing in response to 2 Letters to the Editor, both of which discussed our commentary, entitled "Clinical Research Trials of Psychedelic-Assisted Therapy in Adolescents Aged 16 to 17 Years: Rationale Balanced With Caution."1 We appreciate the thoughtful responses to our commentary, and we invite further dialogue about this important subject. Both letters emphasized the importance in engaging in thoughtful research approaches to ensure the safety of individuals who are administered psychedelics. To ensure safety, ethical and methodologically rigorous research must be conducted across the field of psychedelic medicine. We maintain that conducting such research among adolescents is sensible and worthwhile, but also acknowledge the potential risks associated with extrapolating efficacy data from adult trials and off-label prescribing practices common in child and adolescent psychiatry.

Psychedelics as an intervention for psychological, existential distress in terminally ill patients: A systematic review and network meta-analysis

BACKGROUND

The interest in psychedelics as a therapeutic intervention for existential distress of people with terminal illness grounds on their mechanism of action and effect on the spiritual/existential aspects accompanying end-of-life experiences.

AIMS

This systematic review and network meta-analysis aimed at examining the efficacy and safety of psychedelic compounds for existential distress in terminally ill people.

METHODS

PubMed, CINAHL, PsycINFO, EMBASE, and clinicaltrials.gov were searched for randomized controlled trials (RCTs) administering psychedelics for existential distress in people with terminal illnesses. Meta-analysis estimated the standardized mean difference (SMD) and odds ratio (OR), with corresponding 95% confidence intervals (95% CI), between treated and control groups in pairwise and network comparisons, using random-effects models. Post-treatment measures of depression and anxiety, as proxies of existential distress, and tolerability were the primary outcomes.

RESULTS

Nine studies, involving 606 participants (362 treated with psychedelics: psilocybin, ketamine, 3,4-methylenedioxymethamphetamine, and lysergic acid diethylamide (LSD)) were included. The meta-analysis supported the efficacy of psychedelics on depression (SMD: -0.80 (95% CI: -0.98, -0.63)) and anxiety (SMD: -0.84 (95% CI: -1.20, -0.48)). Network meta-analysis identified psilocybin as the most effective compound for depression, and LSD for anxiety. However, head-to-head comparison between psychedelics did not reach statistical significance. The rates of treatment discontinuation and adverse events between psychedelics and controls were comparable.

CONCLUSIONS

Psychedelics, especially psilocybins and LSD, showed promising effects on depression and anxiety in people with terminal illnesses. Limitations include the small number of RCTs, methodological issues related to blinding, and the lack of direct comparisons between psychedelic compounds. Larger studies and comparative research are needed to consolidate these findings.

Perioperative considerations for patients exposed to hallucinogens

Hallucinogen exposure in patients in the perioperative period presents challenges for anesthesiologists and other anesthesia providers. Acute and chronic exposure to these substances can cause physiological impacts that can affect the function of anesthetic and analgesic medications used during perioperative care. The objective of this narrative review is to educate readers on the wide array of hallucinogens and psychedelics that may influence the perioperative management of patients exposed to these substances. A narrative review of the literature surrounding hallucinogens and psychedelics was completed. Hallucinogens and psychedelics are quite varied in their mechanisms of action and therefore present a variety of perioperative implications and perioperative considerations. Many of these substances increase serotonin levels or act directly at serotonergic receptors. However, there are other relevant actions that may include varied mechanisms from N-methyl-D-aspartate receptor antagonism to stimulation of muscarinic receptors. With hallucinogen exposure rates on the rise, understanding the effects of hallucinogens is important for optimizing management and reducing risks perioperatively for patients with acute or chronic exposure.

Psychedelic Research for Alcohol Use Disorder with Comorbid Major Depressive Disorder: An Unmet Need

PURPOSE OF REVIEW

In this narrative review, we discuss evidence for psilocybin- and LSD-assisted treatment of alcohol use disorder (AUD) and major depressive disorder (MDD). We describe limitations of psychedelic research and posit methodological considerations when designing a trial in patients with both disorders.

RECENT FINDINGS

In AUD, a growing evidence base for psilocybin treatment shows a promising beneficial and sustained effect on measures of drinking frequency. In MDD, a recent meta-analysis has demonstrated that psilocybin therapy provides a large and consistent reduction in depressive symptoms compared to no treatment. Co-occurrence of MDD and AUD is quite prevalent, and this comorbidity exacerbates symptomatology of the two individual disorders and complicates their treatment. Theoretically, patients presenting with both AUD and MDD would benefit from an integrated therapy that could treat MDD and AUD simultaneously. We believe that more research into the efficacy of psilocybin in patients with both AUD and MDD is warranted and justified.

Adverse Events in Studies of Classic Psychedelics: A Systematic Review and Meta-Analysis

Importance

A clear and comprehensive understanding of risks associated with psychedelic-assisted therapy is necessary as investigators extend its application to new populations and indications.

Objective

To assess adverse events (AEs) associated with classic psychedelics, particularly serious AEs (SAEs) and nonserious AEs (NSAEs) requiring medical or psychiatric evaluation.

Data Sources

The search for potentially eligible studies was conducted in the Scopus, MEDLINE, PsycINFO, and Web of Science databases from inception through February 8, 2024.

Study Selection

Two independent reviewers screened articles of classic psychedelics (lysergic acid diethylamide [LSD], psilocybin, dimethyltryptamine [DMT], and 5-methoxy-N,N-dimethyltryptamine [5-MeO-DMT]) involving administration in clinical or research contexts.

Data Extraction and Synthesis

AE data were extracted and synthesized by 2 reviewers and were used for random-effects meta-analysis of AE frequency and heterogeneity. Risk of bias assessment focused on AE ascertainment (eg, systematic assessment and quality of follow-up).

Main Outcomes and Measures

A hybrid approach was used for capture of all reported AEs following high-dose classic psychedelic exposure and confirmatory capture of AEs of special interest, including suicidality, psychotic disorder, manic symptoms, cardiovascular events, and hallucinogen persisting perception disorder. AEs were stratified by timescale and study population type. Forest plots of common AEs were generated, and the proportions of participants affected by SAEs or NSAEs requiring medical intervention were summarized descriptively.

Results

A total of 214 unique studies were included, of which 114 (53.3%) reported analyzable AE data for 3504 total participants. SAEs were reported for no healthy participants and for approximately 4% of participants with preexisting neuropsychiatric disorders; among these SAEs were worsening depression, suicidal behavior, psychosis, and convulsive episodes. NSAEs requiring medical intervention (eg, paranoia, headache) were similarly rare. In contemporary research settings, there were no reports of deaths by suicide, persistent psychotic disorders, or hallucinogen persisting perception disorders following administration of high-dose classic psychedelics. However, there was significant heterogeneity in the quality of AE monitoring and reporting. Of 68 analyzed studies published since 2005, only 16 (23.5%) described systematic approaches to AE assessment, and 20 studies (29.4%) reported all AEs, as opposed to only adverse drug reactions. Meta-analyses of prevalence for common AEs (eg, headache, anxiety, nausea, fatigue, and dizziness) yielded comparable results for psilocybin and LSD.

Conclusions and Relevance

In this systematic review and meta-analysis, classic psychedelics were generally well tolerated in clinical or research settings according to the existing literature, although SAEs did occur. These results provide estimates of common AE frequencies and indicate that certain catastrophic events reported in recreational or nonclinical contexts have yet to be reported in contemporary trial participants. Careful, ongoing, and improved pharmacovigilance is required to understand the risk and benefit profiles of these substances and to communicate such risks to prospective study participants and the public.