This page respects the original work's rights terms and independently introduces its bibliography, abstract, main results, and limitations. It is not a full translation.
About this resource
This page introduces a systematic review and meta-analysis that collected randomized controlled trials of psilocybin-assisted therapy for major depressive disorder and aggregated symptom changes and adverse events. It included 6 trials with a total of 427 participants. These were not simply studies administering a substance; many were conducted in research environments that included preparation, a monitored session, and psychological support afterward.
The studies principally addressed standardized psilocybin, not whole mushrooms containing psilocybin. Product type, participant selection, comparison condition, psychological support, and follow-up time differed among trials, so the review cannot be read as evidence about the effects of “magic mushrooms” in general.
Study design
The authors searched major databases and included randomized trials comparing psilocybin-assisted therapy in adults with major depressive disorder. They pooled changes in depression-rating scales and examined effects by follow-up period, attrition, and adverse events. Risk of bias and heterogeneity among studies were also assessed.
Comparison groups included placebo, low-dose psilocybin, and another antidepressant, so the control conditions were not identical. Strong subjective effects make allocation easier for participants and therapists to infer, potentially causing the blinding usually expected in a drug trial to break down functionally.
Content
The review combined trials involving people who had not responded to conventional antidepressants with trials in broader major depressive disorder. The number of sessions, form of psychological support, raters, and primary scales also differed. A meta-analysis can show an average direction, but it cannot isolate which component contributed to the result.
Expectations, therapeutic alliance, extended support, and research participation itself may also affect symptoms. Appropriate controls are needed to evaluate psilocybin’s pharmacological contribution, but complete control is difficult for an intervention with a highly distinctive experience.
Results
The pooled analysis showed a direction of greater improvement in short-term depression-rating scales than in comparison groups. Effects were generally assessed through several weeks, but studies differed and estimates had a range of uncertainty. Definitions of remission and response also depended on the scale and threshold.
The findings do not establish efficacy for everyone, relapse prevention, long-term safety, or superiority to existing treatments. A synthesis of only 6 trials may be influenced by the same research groups and selected populations.
Limitations
The number of trials and participants was limited, and follow-up was mainly short term. Comparison conditions, psychological support, scales, and definitions of treatment resistance differed. Functional unblinding, expectancy effects, and publication bias cannot be excluded.
Many trials excluded psychotic disorders, risk of mania, serious physical illness, and other conditions, limiting generalization to routine clinical care or unsupervised settings. The evidence base was also too small to detect rare serious adverse events.
Safety
Trials reported acute events including anxiety, headache, nausea, and increased blood pressure, with immediate response available for psychological distress. Changes in mental state, including suicidal ideation or behavior, need to be reviewed according to each trial’s definitions and timing.
This page does not guide treatment, ingestion, or mushroom identification. It is not grounds for independently stopping psychiatric treatment or medication; it introduces evidence together with the research conditions and limitations.
Source and rights
Original source: Menon V, et al. Randomized Controlled Trials of Psilocybin-Assisted Therapy in the Treatment of Major Depressive Disorder: Systematic Review and Meta-Analysis. Acta Psychiatrica Scandinavica. 2025. DOI: 10.1111/acps.13778.
Respecting the publisher’s copyright, this page is a detailed introduction that independently summarizes methods, results, safety, and limitations based on public bibliographic information and the abstract. It is not a full translation or republication of figures and tables.