Single-Dose Psilocybin for a Treatment-Resistant Episode of Major Depression
A single 25 mg dose produced significantly greater reduction in depression scores at three weeks than the 1 mg control, establishing a dose-response signal in the largest psilocybin depression trial to date.
- Institution
- Multi-site (COMPASS Pathways COMP360)
- Design
- Randomized, double-blind, dose-finding phase 2b trial
- Sample size
- 233 participants
- Intervention
- Single dose of 25 mg, 10 mg, or 1 mg (control) synthetic psilocybin (COMP360)
- Year
- 2022
- Condition
- Treatment-resistant depression
Benefit narrowed over 12 weeks; adverse events including suicidal ideation were reported, and the 1 mg comparator is not a true inert placebo.
The largest randomized psilocybin depression trial conducted to date and the centerpiece of the commercial COMP360 development program. Its scale makes it the strongest single dataset on dose-response, while its mixed durability and safety signals illustrate why phase 3 trials are needed.
Summary written by MMI Editorial for clarity. Always consult the primary source for full methodology and results. Confidence rating reflects our assessment of evidence strength.