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Psilocybin for depression

Studies whose primary subject is both Psilocybin and Depression, 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, Depression, major depressive disorder, then ranked by relevance.

Across randomized and open-label trials, psilocybin with psychological support generally produces rapid and often large reductions in depressive symptoms, with several studies reporting that roughly 60-80% of participants maintain clinically significant improvement at follow-up periods of 6 to 12 months. However, the evidence is limited by small samples, difficulty maintaining blinding, strict exclusion criteria, and inconsistent results in the most rigorous comparisons, where psilocybin has not always separated from controls or established antidepressants. The most robust single trial found that a 25 mg dose outperformed a 1 mg control at three weeks, but sustained response at 12 weeks was not clearly demonstrated.

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 produces substantial and sustained decreases in depression and anxiety in patients with life-threatening cancer: A randomized double-blind trial 2016 RCT 51 Supports High-dose psilocybin produced large and sustained decreases in depressed mood and anxiety, with about 80% of participants showing clinically significant improvement at 6-month follow-up.
Rapid and sustained symptom reduction following psilocybin treatment for anxiety and depression in patients with life-threatening cancer: a randomized controlled trial 2016 RCT 29 Supports Single-dose psilocybin (0.3 mg/kg) plus psychotherapy produced rapid, substantial, and enduring reductions in anxiety and depression, with approximately 60-80% of participants continuing to show clinically significant reductions at 6.5 months.
Psilocybin with psychological support for treatment-resistant depression: an open-label feasibility study. 2016 open-label feasibility trial 12 Supports Psilocybin was well tolerated and associated with marked reductions in depressive symptoms at one week and three months after treatment.
Trial of Psilocybin versus Escitalopram for Depression 2021 RCT No effect At week 6, psilocybin did not show a significant difference in antidepressant effects compared with escitalopram; secondary outcomes generally favored psilocybin but lacked correction for multiple comparisons.
Effects of Psilocybin-Assisted Therapy on Major Depressive Disorder 2020 RCT 24 Supports Psilocybin with therapy produced large, statistically significant reductions in depression severity compared with a waiting list control, with 71% showing clinically significant response at week 1 and 54% in remission at week 4.
Single-Dose Psilocybin for a Treatment-Resistant Episode of Major Depression. 2022 phase 2 double-blind RCT 233 Supports A single 25 mg dose of psilocybin, but not 10 mg, significantly reduced depression scores at three weeks compared to a 1 mg control dose; sustained response at 12 weeks was not clearly demonstrated.
Psilocybin with psychological support for treatment-resistant depression: six-month follow-up. 2017 open-label trial 20 Supports Two doses of psilocybin produced large, rapid reductions in depressive symptoms that persisted for six months, with large effect sizes at 5 weeks and 3 and 6 months.
Quality of Acute Psychedelic Experience Predicts Therapeutic Efficacy of Psilocybin for Treatment-Resistant Depression 2018 clinical trial 20 Supports Oceanic boundlessness and dread of ego dissolution during the psilocybin session predicted improvements in depressive symptoms at 5 weeks.
Psilocybin for treatment-resistant depression: fMRI-measured brain mechanisms. 2017 observational cohort 19 Supports Psilocybin treatment decreased amygdala cerebral blood flow and increased default-mode network connectivity, with specific connectivity changes predicting clinical response at five weeks; 47% met criteria for response at 5 weeks.
Patients’ Accounts of Increased “Connectedness” and “Acceptance” After Psilocybin for Treatment-Resistant Depression 2017 qualitative study 20 Supports Patients reported that psilocybin treatment fostered connection and emotional acceptance, unlike conventional treatments which they felt reinforced disconnection and avoidance.
Classic psychedelics: An integrative review of epidemiology, therapeutics, mystical experience, and brain network function. 2019 integrative review Supports Classic psychedelics show strong potential as therapeutics for psychological distress, depression, and addiction, and as tools for studying mystical experiences and brain function.
Single-Dose Psilocybin Treatment for Major Depressive Disorder 2023 phase 2 RCT 104 Supports Psilocybin treatment significantly reduced depressive symptoms and functional disability compared with placebo over 43 days, without serious adverse events.
Increased global integration in the brain after psilocybin therapy for depression. 2022 open-label trial and double-blind phase II RCT Supports In both trials, the antidepressant response to psilocybin was rapid, sustained, and correlated with decreases in fMRI brain network modularity, implying that psilocybin's antidepressant action may depend on a global increase in brain network integration.
Efficacy and safety of psilocybin-assisted treatment for major depressive disorder: Prospective 12-month follow-up 2022 randomized waiting-list controlled study 27 Supports Psilocybin-assisted therapy produced large, durable antidepressant effects through 12 months, with 75% of participants showing treatment response and 58% achieving remission at 12 months.
Therapeutic effects of classic serotonergic psychedelics: A systematic review of modern‐era clinical studies 2020 systematic review 188 Supports Serotonergic psychedelic-assisted therapy appears safe and shows promising early efficacy for several psychiatric conditions, with long-lasting effects after few sessions.
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 mean suicidal ideation item fell from 3.2 to 1.2, with substantial heterogeneity between individuals and no serious adverse events.
Psilocybin and ayahuasca in treatment-resistant depression: clinical evidence, methodological constraints and ethical challenges: a narrative review 2026 narrative review Supports Psilocybin and ayahuasca both show rapid reductions in depressive symptoms in treatment-resistant depression, with psilocybin having more robust evidence for sustained effects; the authors argue that current trials are constrained by strict selection criteria, blinding difficulties, small samples, and ethical gaps.
[The use of psychedelics in psychiatry]. 2026 review Mixed Argues that psilocybin produces consistent and often large improvements in major depressive disorder, yet in the most rigorous trials the predefined primary endpoint does not always reach statistical significance, and certainty of evidence remains low or very low for several indications.
Multilevel Mechanisms and Clinical Efficacy of Psilocybin in Depression Treatment: A Systematic Review 2026 systematic review Supports Reports that single or limited doses of psilocybin, particularly 25 mg, rapidly and sustainably reduce treatment-resistant depression symptoms, with efficacy comparable or superior to escitalopram, and proposes multilevel mechanisms including 5-HT2A receptor activation, BDNF-TrkB signaling, hippocampal neurogenesis, and default mode network remodeling.
354. Effects of psilocybin treatment on cognitive function in Japanese patients with treatment-resistant depression: an open-label study 2026 single-arm, open-label feasibility study 12 Unclear The study is designed to test whether psilocybin therapy changes cognitive function in treatment-resistant depression and whether such changes are direct or mediated by reduced depressive symptoms; no cognitive outcomes are reported yet.
433. Psilocybin reveals diverse antidepressant efficacies across different preclinical models of depression 2026 preclinical animal study Mixed Psilocybin's behavioral effects varied by model, dose schedule, and outcome: chronic and acute multi-dose treatment improved sucrose preference and anxiety-like measures in the mouse chronic stress model, while acute single doses showed limited or no effects in the rat stress and mouse lipopolysaccharide models.
429. Association between subjective experiences and symptom improvement following psilocybin therapy in Japanese patients with treatment-resistant depression: an open-label study 2026 open-label, single-arm feasibility trial 12 Unclear No outcome results are reported yet; the authors aim to examine whether the intensity of subjective experiences after psilocybin is associated with changes in depressive symptoms.
263. Feasibility of psilocybin treatment in Japanese patients with treatment-resistant depression: an open-label study 2026 single-arm, open-label feasibility study 12 Unclear The trial is evaluating whether psilocybin therapy with psychological support is feasible, safe, and potentially antidepressant in Japanese patients with treatment-resistant depression; final feasibility, safety, and clinical outcomes are pending.
475. Psilocin pharmacokinetics and exposure-response relationships in Japanese patients with treatment-resistant depression receiving psilocybin therapy: an open-label study 2026 open-label feasibility trial 12 Unclear The trial is designed to provide the first data on psilocin pharmacokinetics and exposure-response relationships in an Asian population; no pharmacokinetic or clinical outcome results are reported.
Can psilocybin help a patient with chronic depression? 2026 commentary Unclear Argues that evidence for psilocybin in chronic depression is limited and primarily based on treatment-resistant cases, and that while promising results exist, more targeted and extensive research is needed.

Points of agreement

  • Psilocybin with psychological support produces rapid reductions in depressive symptoms across multiple trials and reviews.
  • Several studies report that improvements are sustained for weeks to months, with 60-80% of participants showing clinically significant benefit at follow-up in some trials.
  • The quality of the acute psychedelic experience (e.g., mystical-type or oceanic boundlessness) is consistently reported to predict therapeutic outcomes.
  • Most studies report good tolerability with no serious adverse events attributed to psilocybin.

Conflicts

  • One RCT found no significant difference between psilocybin and escitalopram at week 6, while a systematic review reports psilocybin efficacy comparable or superior to escitalopram.
  • The largest phase 2 RCT found a significant effect for 25 mg at 3 weeks but did not clearly demonstrate sustained response at 12 weeks, whereas open-label and smaller trials report durable effects through 6-12 months.
  • A review notes that in the most rigorous trials the primary endpoint does not always reach statistical significance, contrasting with reviews that describe consistent and often large improvements.
  • Preclinical results are inconsistent across animal models and dose schedules.

Gaps

  • Durability beyond 12 months is largely unstudied.
  • Blinding is difficult to maintain and may inflate effect sizes; expectancy effects are not fully controlled.
  • Most trials exclude patients with comorbidities, high suicide risk, or polypharmacy, limiting generalizability to real-world treatment-resistant depression.
  • Sample sizes are generally small, and several ongoing trials have not yet reported outcomes.
  • Data are lacking from Asian and other non-Western populations.
  • Optimal dosing, number of sessions, and the specific contribution of psychological support versus drug effect remain unclear.
Browse these studies in the library

Common questions

What does the research agree on about psilocybin for depression?
  • Psilocybin with psychological support produces rapid reductions in depressive symptoms across multiple trials and reviews.
  • Several studies report that improvements are sustained for weeks to months, with 60-80% of participants showing clinically significant benefit at follow-up in some trials.
  • The quality of the acute psychedelic experience (e.g., mystical-type or oceanic boundlessness) is consistently reported to predict therapeutic outcomes.
  • Most studies report good tolerability with no serious adverse events attributed to psilocybin.
Where do studies on psilocybin for depression conflict?
  • One RCT found no significant difference between psilocybin and escitalopram at week 6, while a systematic review reports psilocybin efficacy comparable or superior to escitalopram.
  • The largest phase 2 RCT found a significant effect for 25 mg at 3 weeks but did not clearly demonstrate sustained response at 12 weeks, whereas open-label and smaller trials report durable effects through 6-12 months.
  • A review notes that in the most rigorous trials the primary endpoint does not always reach statistical significance, contrasting with reviews that describe consistent and often large improvements.
  • Preclinical results are inconsistent across animal models and dose schedules.
What is still unknown about psilocybin for depression?
  • Durability beyond 12 months is largely unstudied.
  • Blinding is difficult to maintain and may inflate effect sizes; expectancy effects are not fully controlled.
  • Most trials exclude patients with comorbidities, high suicide risk, or polypharmacy, limiting generalizability to real-world treatment-resistant depression.
  • Sample sizes are generally small, and several ongoing trials have not yet reported outcomes.
  • Data are lacking from Asian and other non-Western populations.
  • Optimal dosing, number of sessions, and the specific contribution of psychological support versus drug effect remain unclear.
How we analyze this

This synthesis reads the 15 most-cited and 10 most recent studies whose primary subject is Psilocybin for depression, 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 for depression 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

491 articles · 213 from the last two years · 45,530 participants across 186 studies reporting sample size

Common study designs

review 120 narrative review 14 systematic review 44 randomized controlled trial 43 systematic review and meta-analysis 20

Research volume by year

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489 studies whose primary subject is psilocybin for depression since 2015

Studies about psilocybin for depression per year, 2015 to 2026, peaking at 100 in 2025 Bar chart: one bar per year, taller where more studies were published that year. 0 50 100 2015 2020 2025
2026 is partial
Show the numbers
Studies about psilocybin for depression per year, 2015 to 2026, peaking at 100 in 2025
Year Studies
2015 1
2016 10
2017 7
2018 5
2019 7
2020 16
2021 44
2022 46
2023 84
2024 73
2025 100
2026 96

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)

Psilocybin and ayahuasca in treatment-resistant depression: clinical evidence, methodological constraints and ethical challenges: a narrative review

Frontiers in Psychiatry September 15, 2026 Serena Chiara Civardi, Filippo Besana, Federico Durbano et al.

Background Treatment-resistant depression (TRD) is a major clinical challenge, with many patients failing to respond to conventional antidepressants. Psychedelic compounds such as psilocybin and ayahuasca have recently gained attention as potential rapid-acting therapies. Beyond their neurobiological effects, methodological, ethical, and real-world applicability concerns are critical for...

DOI: 10.3389/fpsyt.2026.1858319 (opens in new tab)

[The use of psychedelics in psychiatry].

Orvosi hetilap September 13, 2026 Szabolcs Kéri

Over the past five years, the literature on the psychiatric use of psychedelic and related treatments has expanded substantially. Several randomized controlled trials and pooled analyses have been conducted in mood disorders, treatment-resistant depression, and post-traumatic stress disorder. Trial methodology, however, remains a fundamental source of uncertainty, and despite the popularity of...

DOI: 10.1556/650.2026.33665 (opens in new tab) Full text (opens in new tab) MDMA Post-traumatic stress disorder Psilocybin Treatment-resistant depression +7

Multilevel Mechanisms and Clinical Efficacy of Psilocybin in Depression Treatment: A Systematic Review

International Journal of Molecular Sciences September 10, 2026 Xizhen Zhang, Xiaowen Zhang, Haiyu Zhang et al.

Depression, characterized by persistent low mood and anhedonia, represents a prevalent affective disorder imposing substantial medical and economic burdens. Current first-line antidepressants are limited by delayed onset and treatment resistance. Psilocybin (PSI) has re-emerged as a promising therapeutic agent with rapid, sustained antidepressant effects. This systematic review was conducted...

DOI: 10.3390/ijms27188052 (opens in new tab)

354. Effects of psilocybin treatment on cognitive function in Japanese patients with treatment-resistant depression: an open-label study

International Journal of Neuropsychopharmacology September 9, 2026 Sota Tomiyama, K Yonezawa, K Kusudo et al.

Abstract Background Cognitive dysfunction is associated with impaired psychosocial functioning in patients with major depressive disorder (MDD). Patients with treatment-resistant depression (TRD) exhibit more pronounced cognitive dysfunction than those with non-resistant MDD, underscoring the need for effective therapeutic strategies. Psilocybin has emerged as a promising treatment for...

DOI: 10.1093/ijnp/pyag040.263 (opens in new tab)

433. Psilocybin reveals diverse antidepressant efficacies across different preclinical models of depression

International Journal of Neuropsychopharmacology September 9, 2026 Z Wang, W Chen, C Hu et al.

Abstract Background Within the rapidly expanding field of psychedelic research, psilocybin, along with its active metabolite psilocin, has emerged as a highly promising candidate in the search for innovative treatments for neuropsychiatric disorders. In this context, preclinical research using animal disease models has produced somewhat inconsistent results when employing standard tests to...

DOI: 10.1093/ijnp/pyag040.302 (opens in new tab)

429. Association between subjective experiences and symptom improvement following psilocybin therapy in Japanese patients with treatment-resistant depression: an open-label study

International Journal of Neuropsychopharmacology September 9, 2026 Lisa Harada, K Yonezawa, K Kusudo et al.

Abstract Background Despite sequential treatments with conventional antidepressants, many patients with depression experience insufficient clinical improvement, referred to as treatment-resistant depression (TRD). Psilocybin, a serotonergic psychedelic acting as a 5-HT2A receptor agonist, has attracted increasing attention as a novel treatment, with clinical trials demonstrating rapid and...

DOI: 10.1093/ijnp/pyag040.300 (opens in new tab)

475. Psilocin pharmacokinetics and exposure-response relationships in Japanese patients with treatment-resistant depression receiving psilocybin therapy: an open-label study

The International Journal of Neuropsychopharmacology September 1, 2026 K Kusudo, K Yonezawa, Sota Tomiyama et al.

Abstract Background Psilocybin, a prodrug metabolized to psilocin, a serotonin 2A receptor agonist, has reemerged as a promising therapeutic option for treatment-resistant depression (TRD). Clinical trials conducted mainly in North America and Europe have demonstrated that psilocybin administered with psychological support can produce rapid and sustained antidepressant effects with favorable...

DOI: 10.1093/ijnp/pyag040.323 (opens in new tab) Full text (opens in new tab)

263. Feasibility of psilocybin treatment in Japanese patients with treatment-resistant depression: an open-label study

The International Journal of Neuropsychopharmacology September 1, 2026 K Yonezawa, K Kusudo, Sota Tomiyama et al.

Abstract Background Despite recent advances in the treatment of major depression, approximately 30% of patients show insufficient improvement with conventional antidepressants, a condition commonly referred to as treatment-resistant depression (TRD). Psilocybin is a classic psychedelic compound that has received renewed attention as a promising therapeutic candidate for TRD. Clinical trials...

DOI: 10.1093/ijnp/pyag040.221 (opens in new tab) Full text (opens in new tab)

Clinical trials

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