Efficacy of psilocybin for treating symptoms of depression: systematic review and meta-analysis
BMJ May 1, 2024 Athina-Marina Metaxa, Mike Clarke 78 citations
A systematic review and meta-analysis of seven randomized trials involving 436 adults with clinically significant depression found that psilocybin produced a moderate-to-large reduction in depression symptoms compared with placebo or non-psychoactive comparators (Hedges' g = 0.66). Greater improvements were linked to secondary depression, use of self-report scales, older age, and prior psychedelic use. All studies had moderate risk of bias, but the evidence was rated as moderate certainty. The authors conclude that further research is needed to clarify expectancy effects, moderating factors, and treatment delivery.