Risk of bias in randomized clinical trials on psychedelic medicine: A systematic review
Journal of Psychopharmacology July 1, 2023 Oliver Rumle Hovmand, Emil Deleuran Poulsen, Sidse Arnfred et al. 52 citations
A systematic review of clinical trials on classical psychedelics (psilocybin, peyote, ayahuasca/DMT, and LSD) for psychiatric conditions found that all but one of the ten included trials were rated as high risk of bias. The trials predominantly enrolled white, highly educated participants, had small sample sizes, and experienced considerable dropout. Blinding was either unsuccessful or not reported regardless of the type of placebo used. Few trials published protocols, statistical analysis plans, or measures of psychotherapy fidelity. The authors suggest that future trials use parallel-group designs with active placebos in psychedelic-naïve populations, publish protocols and analysis plans, employ blinded clinician-rated outcomes, evaluate blinding, and measure expectancy and therapeutic fidelity.