Efficacy of Psilocybin-Assisted Therapy in Major Depressive Disorder: A Systematic Review and Meta-Analysis
Psychiatry International June 15, 2026 Angel Labra-Lorenzana, Dania Nimbe Lima Sanchez, Christian Alejandro Delaflor-Wagner et al.
Psilocybin-assisted psychotherapy (PAP) is associated with large short-term reductions in depressive symptom severity among adults with major depressive disorder. A meta-analysis of ten clinical trials found an overall large effect (d = 1.15), with within-subject designs showing larger estimates (d = 1.63) than between-subject controlled comparisons (d = 0.96). Adverse events were transient and manageable, with no increased risk of serious adverse events on dosing days. However, long-term efficacy remains understudied, and the overall certainty of evidence is low to moderate. Larger, rigorously blinded trials are needed.