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Psilocybin and psychedelic-assisted therapy

Studies whose primary subject is both Psilocybin and Psychedelic-assisted therapy, with an evidence synthesis read across the most-cited and most recent of them.

State of the evidence

Synthesized

Synthesized from 25 studies in the library · AI-generated, grounded in the abstracts below

Found by searching the library for Psilocybin, magic mushrooms, psilocin, psychedelic mushrooms, Psychedelic-assisted therapy, psychedelic therapy, then ranked by relevance.

Across a range of designs, psilocybin-assisted therapy is consistently associated with rapid and often large reductions in depression, anxiety, and substance use, with several trials showing benefits lasting months to years. Placebo-controlled trials and meta-analyses support a real but smaller between-group effect (roughly g = 0.5-1.2), while open-label and qualitative work suggests additional psychological mechanisms such as increased connectedness, acceptance, and cognitive flexibility. The main caveats are small samples, open-label designs, heterogeneity in psychotherapy and dosing, and uncertainty about how well effects hold up in larger phase 3 trials and real-world health systems.

Evidence by study

Direction is which way each study's own result points, not our rating of the study.

What the directions mean
Supports:
the study found the intervention worked, or its hypothesis held.
Opposes:
it found the opposite, no benefit or a harm.
No effect:
no significant difference either way.
Mixed:
effects in both directions within the same study.
Unclear:
the abstract does not report a direction.
Study Design Sample size Direction Finding
Psilocybin with psychological support for treatment-resistant depression: six-month follow-up. 2017 open-label trial 20 Supports Two psilocybin doses produced large reductions in depressive symptoms (Cohen's d = 2.2 at week 1, 1.4 at 6 months) that remained significant at six months.
Psilocybin occasioned mystical-type experiences: immediate and persisting dose-related effects. 2011 randomized controlled trial 18 Supports High doses (20 and 30 mg/70 kg) occasioned mystical-type experiences with sustained positive changes in attitudes, mood, and behavior that were undiminished at 14 months.
Percentage of Heavy Drinking Days Following Psilocybin-Assisted Psychotherapy vs Placebo in the Treatment of Adult Patients With Alcohol Use Disorder 2022 randomized controlled trial 95 Supports Psilocybin plus psychotherapy led to 9.7% heavy drinking days over 32 weeks versus 23.6% with active placebo plus psychotherapy.
Patients’ Accounts of Increased “Connectedness” and “Acceptance” After Psilocybin for Treatment-Resistant Depression 2017 qualitative study 20 Supports Patients described psilocybin treatment as fostering connection and emotional acceptance, in contrast to conventional treatments they felt reinforced disconnection and avoidance.
Increased global integration in the brain after psilocybin therapy for depression. 2022 open-label trial and double-blind phase II randomized controlled trial Supports Antidepressant response to psilocybin was rapid and sustained and correlated with decreased fMRI brain network modularity, while escitalopram response was milder with no such change.
Long-term follow-up of psilocybin-assisted psychotherapy for psychiatric and existential distress in patients with life-threatening cancer 2020 long-term within-subjects follow-up analysis 15 Supports Reductions in anxiety, depression, hopelessness, demoralization, and death anxiety were sustained at 3.2 and 4.5 years, with 60-80% still meeting criteria for clinically significant response.
Single-dose psilocybin-assisted therapy in major depressive disorder: A placebo-controlled, double-blind, randomised clinical trial. 2023 double-blind, randomised clinical trial 52 Supports A single moderate dose (0.215 mg/kg) significantly reduced depressive symptoms versus placebo at 14 days (MADRS Cohen's d = 0.97; BDI d = 0.67), with 54% meeting remission criteria.
Psilocybin therapy increases cognitive and neural flexibility in patients with major depressive disorder. 2021 open-label study 24 Mixed Psilocybin therapy increased cognitive flexibility for at least four weeks, but greater increases in neural flexibility between the ACC and PCC were associated with less improvement in cognitive flexibility.
Theorizing that Psychedelic Assisted Therapy May Play a Role in the Treatment of Trauma-Induced Personality Disorders. 2024 theoretical or philosophical paper Unclear Argues that borderline personality disorder may be reclassified as traumatic personality stress disorder and that psychedelic-assisted therapy may be a pathway for treating both BPD and PTSD.
Patient Experiences of Psilocybin-Assisted Psychotherapy: An Interpretative Phenomenological Analysis 2017 qualitative study 13 Supports Participants described psilocybin-assisted psychotherapy as providing meaningful experiences and revised life priorities, suggesting it may be an effective treatment for psychological distress in cancer patients.
Psychedelic therapy for smoking cessation: Qualitative analysis of participant accounts 2018 qualitative follow-up study 12 Supports Participants attributed smoking cessation to vivid insights, persistent interconnectedness, awe, and curiosity, with preparatory counseling and study rapport seen as vital.
Psychedelic-Assisted Psychotherapy: A Paradigm Shift in Psychiatric Research and Development 2018 review Supports Argues that psychedelic-assisted psychotherapy challenges the current psychiatric paradigm by offering effective treatments and explanations incorporating social, cultural, and trauma-related factors.
Implications for psychedelic-assisted psychotherapy: functional magnetic resonance imaging study with psilocybin 2012 randomized controlled trial 10 Supports Psilocybin enhanced autobiographical recollection, producing additional visual and sensory cortical activations and higher ratings of memory vividness and visual imagery compared to placebo.
Novel psychopharmacological therapies for psychiatric disorders: psilocybin and MDMA. 2016 review Supports Psilocybin and MDMA show promise as therapeutics for several difficult-to-treat conditions when used as adjuncts to psychotherapy, though further research is needed.
A Meta-Analysis of Placebo-Controlled Trials of Psychedelic-Assisted Therapy 2020 systematic review Supports Across nine randomized placebo-controlled trials, psychedelic-assisted therapy showed a significant mean between-groups effect size of Hedges g = 1.21, with effects generally maintained at follow-up.
Exploratory safety, tolerability, and feasibility of psilocybin-assisted psychotherapy for adults with co-occurring treatment-resistant depression and cluster B personality disorders 2026 secondary analysis of a clinical trial 10 Supports Mean MADRS scores declined from 30.4 pre-treatment to 22.3 at six months and suicidal ideation fell from 3.2 to 1.2, with substantial heterogeneity and no serious adverse events.
Oncology Providers' Perspectives on Psychedelic-Assisted Therapy. 2026 cross-sectional survey 385 Opposes Most oncology providers (80%) did not feel comfortable counseling patients on psychedelic-assisted therapy, and only 44% were familiar with its legal status.
Pilot study comparing the effects of high dose THC to high dose psilocybin and placebo in the set and setting of a classic psychedelic therapy session 2026 pilot human laboratory study 4 Mixed A 25 mg oral dose of THC produced subjective experiences similar to 25 mg psilocybin, and dronabinol was mistaken for a classic hallucinogen, suggesting set and setting can influence THC's subjective effects.
Psilocybin-assisted psychotherapy for substance use disorders as a complex intervention: A systematic review of efficacy, mechanisms and psychotherapeutic frameworks 2026 systematic review Supports Across 17 studies, psilocybin-assisted psychotherapy was associated with reductions in substance use, higher abstinence rates, and improved well-being, though findings were heterogeneous and design-dependent.
Psilocybin-containing mushroom-assisted psychotherapy is associated with sustained psychological and somatic improvements: two case studies from Jamaica 2026 case study 2 Supports Both patients reported improvements in psychological and somatic symptoms, including reduced shame, increased self-confidence, pain reduction, and improved mood, though spontaneous improvements cannot be excluded.
Music Playlist Use in Clinical Trials of Psychedelic Assisted Psychotherapy: A Systematic Review 2026 systematic review 36 Unclear Music use in psychedelic-assisted psychotherapy varies considerably with no standardized protocol across studies.
Developing Methods for Observing Awe Narration in Psilocybin-Assisted Therapy. 2026 observational study 8 Supports Awe narration during psilocybin-assisted therapy can be reliably identified by human coders, with confidence significantly higher when vastness was present.
Trials, trips, and tribulations: pathways for implementing psychedelic therapy in Ireland. 2026 review Mixed Notes that early-phase studies yielded encouraging results but recent larger phase 3 trials have shown more modest effects, and integrating psychedelic therapies into public healthcare faces regulatory, workforce, and evaluation challenges.
Meaning-Centered Psychotherapy for Psilocybin-Assisted Therapy Among Patients with Advanced Cancer and Depression: Rationale and Preliminary Evaluation of MCP-PSIL. 2026 qualitative study 13 Supports Meaning-centered psychotherapy was seen as a natural therapeutic partner across the psilocybin-assisted therapy continuum, and a 5-session MCP-PSIL model was developed from participant feedback.
Effect of psilocybin-assisted psychotherapy on anxiety symptoms: A systematic review and meta-analysis 2026 systematic review 25 Supports Psilocybin-assisted psychotherapy produced a large within-groups effect (Hedge's g = 0.96) and a small between-groups effect (Hedge's g = 0.48) on anxiety, with high heterogeneity and variable study quality.

Points of agreement

  • Multiple trials and reviews report rapid and often large reductions in depression, anxiety, and substance use after psilocybin-assisted therapy.
  • Benefits are frequently sustained for months to years in follow-up analyses, including in cancer-related distress and treatment-resistant depression.
  • Qualitative studies consistently describe increased connectedness, acceptance, meaning, and cognitive flexibility as perceived mechanisms.
  • Meta-analyses find significant between-group effects versus placebo, though smaller than within-group effects.

Conflicts

  • Between-group effects in meta-analyses (g = 0.48-1.21) are smaller than the large within-group effects reported in open-label trials.
  • One review notes that recent larger phase 3 trials show more modest effects than early-phase studies.
  • One open-label study found that greater neural flexibility was associated with less cognitive improvement, an unexpected direction.
  • Oncology providers report low comfort and familiarity with psychedelic-assisted therapy despite growing research.

Gaps

  • Durability beyond a few years and in larger, more diverse samples is not well established.
  • Blinding integrity is difficult to maintain and rarely assessed.
  • Optimal dosing, number of sessions, and psychotherapy protocols are not standardized.
  • Long-term safety, drug interactions, and real-world implementation in public health systems remain uncertain.
  • Populations studied are small and often exclude complex comorbidities.
Browse these studies in the library

Common questions

What does the research agree on about psilocybin and psychedelic-assisted therapy?
  • Multiple trials and reviews report rapid and often large reductions in depression, anxiety, and substance use after psilocybin-assisted therapy.
  • Benefits are frequently sustained for months to years in follow-up analyses, including in cancer-related distress and treatment-resistant depression.
  • Qualitative studies consistently describe increased connectedness, acceptance, meaning, and cognitive flexibility as perceived mechanisms.
  • Meta-analyses find significant between-group effects versus placebo, though smaller than within-group effects.
Where do studies on psilocybin and psychedelic-assisted therapy conflict?
  • Between-group effects in meta-analyses (g = 0.48-1.21) are smaller than the large within-group effects reported in open-label trials.
  • One review notes that recent larger phase 3 trials show more modest effects than early-phase studies.
  • One open-label study found that greater neural flexibility was associated with less cognitive improvement, an unexpected direction.
  • Oncology providers report low comfort and familiarity with psychedelic-assisted therapy despite growing research.
What is still unknown about psilocybin and psychedelic-assisted therapy?
  • Durability beyond a few years and in larger, more diverse samples is not well established.
  • Blinding integrity is difficult to maintain and rarely assessed.
  • Optimal dosing, number of sessions, and psychotherapy protocols are not standardized.
  • Long-term safety, drug interactions, and real-world implementation in public health systems remain uncertain.
  • Populations studied are small and often exclude complex comorbidities.
How we analyze this

This synthesis reads the 15 most-cited and 10 most recent studies whose primary subject is Psilocybin and psychedelic-assisted therapy, up to 25 in all. The most-cited set anchors the established evidence, and the recent set surfaces work that is too new to have gathered citations yet.

A study qualifies only when Psilocybin and psychedelic-assisted therapy or a known alias appears in its title or keywords, so broad reviews that mention it only in passing are left out. Each study is read from its abstract, strongest evidence first, and the summary reports the direction of the results along with any conflicts and gaps.

The full method, including what a person does and does not review, is on the methods page.

Ask your own question in the Research Synthesis Tool

249 articles · 96 from the last two years · 12,328 participants across 105 studies reporting sample size

Common study designs

review 48 qualitative study 18 systematic review 23 randomized controlled trial 15 theoretical or philosophical paper 27

Research volume by year

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247 studies whose primary subject is psilocybin and psychedelic-assisted therapy since 2011

Studies about psilocybin and psychedelic-assisted therapy per year, 2011 to 2026, peaking at 54 in 2025 Bar chart: one bar per year, taller where more studies were published that year. 0 30 60 2015 2020 2025
2026 is partial
Show the numbers
Studies about psilocybin and psychedelic-assisted therapy per year, 2011 to 2026, peaking at 54 in 2025
Year Studies
2011 1
2012 1
2013 0
2014 0
2015 0
2016 1
2017 4
2018 6
2019 1
2020 9
2021 15
2022 27
2023 51
2024 48
2025 54
2026 29

Research

Synthesize the evidence →

Exploratory safety, tolerability, and feasibility of psilocybin-assisted psychotherapy for adults with co-occurring treatment-resistant depression and cluster B personality disorders

npj Mental Health Research September 16, 2026 Orly Lipsitz, Ryan M Brudner, Zoe Doyle et al.

Cluster B personality disorders (PDs) are highly comorbid with depression and are associated with attenuated antidepressant response. No clinical trials to date have reported on psilocybin-assisted psychotherapy (PAP) in comorbid treatment-resistant depression (TRD) and PDs. This is the first clinical trial to describe a subgroup of ten participants with a comorbid PD ( n = 9 cluster B; n = 1...

DOI: 10.1038/s44184-026-00248-9 (opens in new tab) Full text (opens in new tab)

Oncology Providers' Perspectives on Psychedelic-Assisted Therapy.

The American journal of hospice & palliative care August 28, 2026 Krishna Hanubal, Akul Munjal, Jino Park et al.

PurposeDespite most psychedelic substances remaining Schedule I, clinical research exploring psychedelic-assisted therapy (PAT) in oncology is expanding. We sought to assess oncology providers' attitudes toward and understanding of PAT.MethodsWe conducted a cross-sectional survey of healthcare professionals involved in oncology across five academic institutions in California, South Carolina,...

DOI: 10.1177/10499091261483604 (opens in new tab) Full text (opens in new tab) MDMA Ketamine Psilocybin Antidepressants +4

Pilot study comparing the effects of high dose THC to high dose psilocybin and placebo in the set and setting of a classic psychedelic therapy session

Psychopharmacology August 27, 2026 Frederick S. Barrett, David Wolinsky, Zach Daily et al.

RATIONALE: Delta-9-tetrahydrocannabinol (Δ9-THC) has been reported to evoke psychedelic-like experiences at high doses in some individuals. However, the doses of Δ9-THC that occasion such effects and the phenomenology of these experiences are poorly understood. OBJECTIVES: This brief report presents preliminary findings from a pilot human laboratory study that directly compared the acute...

DOI: 10.1007/s00213-026-07138-0 (opens in new tab) Full text (opens in new tab)

Psilocybin-assisted psychotherapy for substance use disorders as a complex intervention: A systematic review of efficacy, mechanisms and psychotherapeutic frameworks

Journal of Psychopharmacology August 17, 2026 Lana Strika-Bruneau, Chérine Elhssaini, Baptiste Fauvel et al.

Background: Psychedelic-assisted psychotherapy (PAP) shows promise for substance use disorders (SUDs), yet the respective contributions of pharmacological, experiential, psychotherapeutic, and contextual factors remain insufficiently understood. Objective: To synthesize contemporary clinical evidence on PAP for SUDs, with particular attention to therapeutic frameworks, dosing strategies,...

DOI: 10.1177/02698811261473436 (opens in new tab)

Psilocybin-containing mushroom-assisted psychotherapy is associated with sustained psychological and somatic improvements: two case studies from Jamaica

Frontiers in Psychiatry July 29, 2026 Caitlyn Hanna Sams, Jasmine Davis, Anuradha Ramdas et al.

We report two case studies that examine the therapeutic potential of structured psilocybin-containing mushroom biomass regimens administered within a clinical framework, evaluating their impact on mental health outcomes as well as associated somatic symptoms. Two patients underwent the De La Haye Psilocybin Treatment Protocol (DPTP), which integrates micro- and high-doses (combined psilocybin...

DOI: 10.3389/fpsyt.2026.1876189 (opens in new tab)

Music Playlist Use in Clinical Trials of Psychedelic Assisted Psychotherapy: A Systematic Review

Journal of Clinical Psychology June 15, 2026 Lucas Cruz, Fernando R. Beserra, Julia M.k. Freind et al.

Recent studies have shown promising results for psychedelics in the treatment of psychiatric disorders. Both in clinical and recreational settings, contextual elements, such as music, can influence the experience of users and may be linked to positive outcomes. This systematic review identifies how music is being selected and used in psychedelisc-assisted psychotherapy (PAP). The search adopted...

DOI: 10.1002/jclp.70167 (opens in new tab) Psilocybin Music therapy Clinical trial Scopus +8

Developing Methods for Observing Awe Narration in Psilocybin-Assisted Therapy.

Healthcare (Basel, Switzerland) June 5, 2026 Elise C. Tarbi, Ian Bhatia, Nabil Balach et al.

Background: Understanding the benefits of psychedelic-assisted therapy (PAT) will require scientific attention to the causal interaction between the therapeutic context and process. Measuring what actually happens during PAT in large-scale studies will be an essential component of this work. Objective: We aim to develop and preliminarily evaluate the feasibility and reliability of a direct...

DOI: 10.3390/healthcare14111589 (opens in new tab) Full text (opens in new tab) Psilocybin Psychedelic-assisted therapy Awe Interpersonal communication +1

Trials, trips, and tribulations: pathways for implementing psychedelic therapy in Ireland.

The International Journal of Neuropsychopharmacology June 2, 2026 John R. Kelly, Christopher Sheridan, Patricia Iusan et al.

Classical serotonergic psychedelics, such as psilocybin, show emerging evidence of therapeutic potential across a range of mental health disorders, including depression, anxiety, and substance use disorders, with indications of transdiagnostic efficacy. While early-phase studies yielded encouraging results, recent larger-scale phase 3 trials, such as those evaluating psilocybin for...

DOI: 10.1093/ijnp/pyag028 (opens in new tab) Full text (opens in new tab) Psilocybin Psychedelic therapy Psychedelic-assisted therapy Clinical trials +1

Meaning-Centered Psychotherapy for Psilocybin-Assisted Therapy Among Patients with Advanced Cancer and Depression: Rationale and Preliminary Evaluation of MCP-PSIL.

Psychedelic medicine (New Rochelle, N.Y.) June 1, 2026 William E Rosa, Stephanie Napolitano, Natalie Mcandrew et al.

Psilocybin shows encouraging outcomes for patients with cancer and major depressive disorder (MDD). However, there is insufficient evidence on the use of evidence-based psychotherapeutic interventions to consistently guide and standardize psilocybin preparation, dosing, and integration. Meaning-centered psychotherapy (MCP) is a manualized, brief psychotherapeutic intervention that enhances...

DOI: 10.1177/28314425251363983 (opens in new tab) Full text (opens in new tab) Major depressive disorder Psilocybin Psychedelic-assisted therapy Cancer +2

Effect of psilocybin-assisted psychotherapy on anxiety symptoms: A systematic review and meta-analysis

Journal of Psychedelic Studies May 29, 2026 Alex P. Hood, Gary R Elkins

Abstract Background and Aims Psilocybin-assisted psychotherapy (PAP) is a novel, transdiagnostic treatment in which the 5-HT2A receptor agonist psilocybin is combined with psychotherapy. Studies to date have evaluated PAP's effects on depression, substance use, and end-of-life adjustment. Relatively less attention has been given to its effects on anxiety symptoms, which are highly comorbid with...

DOI: 10.1556/2054.2026.00507 (opens in new tab) Full text (opens in new tab) Anxiety disorder Intervention counseling Systematic review Demographics +8

Clinical trials

All psilocybin and psychedelic-assisted therapy trials →