title: Mystical-type experiences occasioned by psilocybin mediate the attribution of personal meaning and spiritual significance 14 months later.
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.
authors.affiliation: Department of Psychiatry and Behavioral Sciences and Department of Neuroscience, Johns Hopkins University, School of Medicine, Baltimore, MD, USA. rgriff@jhmi.edu
authors.forename: Rr
authors.initials: R
authors.lastname: Griffiths
authors.forename: Wa
authors.initials: W
authors.lastname: Richards
authors.forename: Mw
authors.initials: M
authors.lastname: Johnson
authors.forename: Ud
authors.initials: U
authors.lastname: McCann
authors.forename: R
authors.initials: R
authors.lastname: Jesse
mesh_terms: D000284:Administration, Oral; D000328:Adult; D000339:Affect; D005260:Female; D005500:Follow-Up Studies; D006213:Hallucinogens; D006801:Humans; D019359:Knowledge; D008297:Male; D008875:Middle Aged; D009228:Mysticism; D010551:Personality; D011562:Psilocybin / Q000008:administration & dosage / Q000494:pharmacology*; D011788:Quality of Life; D012067:Religion; D029181:Spirituality; D011795:Surveys and Questionnaires; D013997:Time Factors
chemical_list: D006213:Hallucinogens; D011562:Psilocybin