Meta-analysis · 2026
Review of 7 psilocybin trials in major depression looks at dose and number of sessions
- Original title
- Therapeutic effects of psilocybin in major depressive disorder: a systematic review and meta-analysis exploring dose effects.
- Authors
- He Z, Wang Y, Chen J, et al.
- Journal
- European archives of psychiatry and clinical neuroscience, 2026
- Molecules
- Psilocybin
- Conditions
- Depression
- Participants
- 464
- Evidence grade
- Moderate
- Source
- Read the original paper
The question
Does psilocybin help adults with major depressive disorder, and is there a dose and dosing schedule that works best?
What they did
Researchers searched four research databases up to February 23, 2024, for studies of psilocybin in adults diagnosed with major depressive disorder. Animal studies, case series and previous reviews were excluded. Two reviewers independently selected studies and pulled out the data, and trial quality was rated using the Cochrane Handbook method. Seven trials with 464 participants in total were included, one of which was a conference meeting abstract rather than a full paper.
What they found
Pooled across the seven trials, psilocybin was linked to significant improvement in depression scores and was described as safe and tolerable in these study settings. Within the range studied, higher doses and a second dosing session were associated with larger effects. The authors suggest a dose of 35-50 mg per 70 kg of body weight, given twice, as a promising strategy for future research. The abstract does not report the size of the effect, response rates or remission rates in numbers.
The fine print
The included trials had small sample sizes and short follow-up, so longer-term benefit and safety are unknown. One of the seven sources was a meeting abstract, which has not gone through full peer review. The abstract reports no effect sizes, confidence intervals or adverse-event counts, so the strength of the findings cannot be checked. Dose suggestions come from comparing across trials, not from a head-to-head trial designed to test doses. This summary is based on the abstract only.
What it means
Taken together, the existing trials point to psilocybin reducing depression symptoms in adults with major depression, with hints that larger doses and a second session may matter. The evidence base is still small and short-term, and the suggested dosing range should be treated as a research question, not a settled answer.
Evidence grade: Moderate. A meta-analysis of seven trials judged to be of moderate quality, but the pooled sample is small, follow-up is short, and one included source was only a conference abstract.
This summary is based on the study’s published abstract.