Post-acute psychological effects of classical serotonergic psychedelics: a systematic review and meta-analysis
Psychological Medicine November 4, 2020 Simon B. Goldberg, Benjamin Shechet, Christopher R. Nicholas et al. 66 citations
Classical psychedelics such as psilocybin, ayahuasca, and LSD produce significant psychological effects lasting at least 24 hours after administration, according to a systematic review and meta-analysis of 34 experimental studies involving 549 participants. Large effects were observed for reducing targeted symptoms in psychiatric samples, improving negative and positive affect, social outcomes, and existential or spiritual well-being, with between-group effect sizes ranging from Hedges' g = 0.84 to 1.08. Effects may be larger in clinical samples. Evidence for changes in personality traits or mindfulness was weak. No post-acute adverse effects were found, but high risk of bias, heterogeneity, and possible publication bias underscore the need for larger, placebo-controlled trials.