This systematic review and meta-analysis (s=15) of randomised controlled trials found that psilocybin-assisted therapy was linked to a larger reduction in depression scores than control conditions. The review included 801 participants overall, with 585 in the main analysis, but many studies were small or at risk of bias.
Depression is a major cause of disability worldwide, motivating interest in psilocybin as a potential treatment. Here we present a living systematic review and open-data meta-analytic resource on psilocybin treatment for depressive symptoms. In this initial release, 15 randomized controlled trials comprising 801 participants are included in the database, with 12 of those studies included in our primary model (n = 585) using inverse-variance random-effects modeling of standardized mean differences on primary outcomes. Compared with control conditions, psilocybin showed a greater reduction in depression scores (Hedges’ g = −0.90). This systematic review and meta-analysis suggests that psilocybin-assisted therapy results in substantial decreases in depressive symptoms across studies to date. However, many studies have small sample sizes or risk of bias. This living systematic review, meta-analysis, database and online dashboard (sypres.io) will continue to be updated as evidence emerges, providing a valuable resource for researchers in a rapidly evolving field.