Classic psychedelics and personality: An updated systematic review.
Journal of psychopharmacology (Oxford, England) May 31, 2026 Anna Beatriz Vicentini, Caio César De Paula, José Augusto Silva Reis et al.
A systematic review of 48 studies (14 experimental, 34 observational) covering 2016–2024 found that classic psychedelics—such as psilocybin and ayahuasca—most consistently increase the personality trait Openness and reduce Neuroticism. Changes in Extraversion, Agreeableness, and Conscientiousness were more variable. Microdosing was linked to modest reductions in Neuroticism and higher Absorption. Most studies used the Five-Factor Model. The findings suggest psychedelics can promote lasting personality changes, but contradictory results remain, and future research should combine experimental and naturalistic designs with longer follow-ups.