Long-term effects of psychedelic drugs: A systematic review
Neuroscience & Biobehavioral Reviews March 16, 2020 Jacob S. Aday, Cayla M. Mitzkovitz, Emily K. Bloesch et al. 260 citations
A systematic review of 34 experimental studies on classic psychedelics with follow-up periods of at least two weeks found lasting changes in personality, attitudes, depression, spirituality, anxiety, wellbeing, substance misuse, meditative practices, and mindfulness. Psilocybin was the most commonly administered drug. Mystical experiences, connectedness, emotional breakthrough, and increased neural entropy were linked to these long-term psychological changes. With proper screening, preparation, supervision, and integration, participants reported few aversive side effects. The review calls for larger, more diverse samples, longer longitudinal designs, stronger control conditions, and standardized dosages in future research.