Mystical-type experiences occasioned by psilocybin mediate the attribution of personal meaning and spiritual significance 14 months later

TLDR

Psilocybin has been used religiously for centuries, yet its long‑term effects remain poorly understood scientifically. This study reports a 14‑month follow‑up to assess how early psilocybin‑induced experiences relate to later personal meaning and spiritual significance. Thirty‑six hallucinogen‑naïve adults, all regularly engaged in religious or spiritual practices, received oral psilocybin (30 mg/70 kg) on one of two or three sessions (with methylphenidate on the others) while encouraged to close their eyes and focus inward. At follow‑up, 58 % rated the psilocybin experience among their five most personally meaningful events and 67 % among their five most spiritually significant, 64 % reported increased well‑being, 58 % met criteria for a complete mystical experience, and mystical experience scores on the session day predicted these high follow‑up ratings.

Abstract

Psilocybin has been used for centuries for religious purposes; however, little is known scientifically about its long-term effects. We previously reported the effects of a double-blind study evaluating the psychological effects of a high psilocybin dose. This report presents the 14-month follow-up and examines the relationship of the follow-up results to data obtained at screening and on drug session days. Participants were 36 hallucinogen-naïve adults reporting regular participation in religious/ spiritual activities. Oral psilocybin (30 mg/70 kg) was administered on one of two or three sessions, with methylphenidate (40 mg/70 kg) administered on the other session(s). During sessions, volunteers were encouraged to close their eyes and direct their attention inward. At the 14-month follow-up, 58% and 67%, respectively, of volunteers rated the psilocybin-occasioned experience as being among the five most personally meaningful and among the five most spiritually significant experiences of their lives; 64% indicated that the experience increased well-being or life satisfaction; 58% met criteria for having had a 'complete' mystical experience. Correlation and regression analyses indicated a central role of the mystical experience assessed on the session day in the high ratings of personal meaning and spiritual significance at follow-up. Of the measures of personality, affect, quality of life and spirituality assessed across the study, only a scale measuring mystical experience showed a difference from screening. When administered under supportive conditions, psilocybin occasioned experiences similar to spontaneously occurring mystical experiences that, at 14-month follow-up, were considered by volunteers to be among the most personally meaningful and spiritually significant of their lives.