Psychopharmacology
July 7, 2006
Roland R. Griffiths, William A. Richards, U. Mccann et al.
1,684 citations
A high dose of psilocybin, given under supportive conditions to hallucinogen-naïve adults who regularly participate in religious or spiritual activities, produced acute perceptual changes, subjective experiences, and labile moods including anxiety. It also increased measures of mystical experience. Two months later, volunteers rated the psilocybin experience as having substantial personal meaning and spiritual significance and attributed sustained positive changes in attitudes and behavior to it, consistent with ratings by community observers. The ability to prospectively occasion such experiences allows rigorous scientific investigation of their causes and consequences.
Psychopharmacology
December 1, 2011
Roland R. Griffiths, Matthew W Johnson, William A Richards et al.
938 citations
Psilocybin can produce mystical-type experiences that lead to lasting positive changes in attitudes, mood, and behavior. In a double-blind study, 18 adults (17 with no prior hallucinogen use) received 0, 5, 10, 20, or 30 mg/70 kg psilocybin in five sessions under supportive conditions. At the two highest doses, 72% of volunteers reported a mystical-type experience, and 39% experienced extreme anxiety or fear. One month later, participants rated these sessions as having substantial personal and spiritual significance, with the ascending dose sequence showing greater positive effects. At 14 months, these positive ratings remained undiminished and were consistent with observer reports. The effects generally increased with dose.
Journal of Psychopharmacology
May 30, 2008
R. R. Griffiths, Wa Richards, Mw Johnson et al.
883 citations
A double-blind study of 36 hallucinogen-naïve adults who regularly participated in religious or spiritual activities found that a single high dose of psilocybin (30 mg/70 kg) produced experiences that, at a 14-month follow-up, were rated among the five most personally meaningful (58%) and spiritually significant (67%) experiences of their lives. 64% reported increased well-being or life satisfaction, and 58% met criteria for a complete mystical experience. The mystical experience assessed on the session day was central to the high ratings of personal meaning and spiritual significance at follow-up. Only a scale measuring mystical experience showed a difference from screening among measures of personality, affect, quality of life, and spirituality.
Journal of Psychopharmacology
August 31, 2016
Theresa M. Carbonaro, Matthew P. Bradstreet, Frederick S. Barrett et al.
541 citations
In a survey of 1,993 people who recalled their worst 'bad trip' after taking psilocybin mushrooms, 39% ranked it among the top five most challenging experiences of their lives. Eleven percent put themselves or others at risk of physical harm, with factors such as higher dose, longer duration, and lack of physical comfort or social support increasing that risk. About 2.6% acted aggressively and 2.7% needed medical help. Among those whose experience was more than a year prior, 7.6% sought treatment for lasting psychological symptoms, with three cases linked to enduring psychotic symptoms and three to attempted suicide. Despite difficulties, 84% reported benefiting from the experience. The incidence of risky behavior or lasting distress is very low when psilocybin is given in controlled laboratory settings.
Journal of Psychopharmacology
October 11, 2017
Roland R. Griffiths, Matthew W. Johnson, William A. Richards et al.
528 citations
A double-blind trial compared a high dose of psilocybin (20 and 30 mg/70 kg) with a very low dose (1 mg/70 kg) in healthy adults who also undertook a program of meditation and spiritual practices. At six months, the high-dose groups, compared with the low-dose group, showed large, significant positive changes in interpersonal closeness, gratitude, life meaning, forgiveness, death transcendence, daily spiritual experiences, religious faith and coping, and community observer ratings. The enduring trait-level increases in prosocial attitudes and healthy psychological functioning were linked to the mystical-type experience occasioned by psilocybin and the rate of meditation or spiritual practices.
PLoS One
April 23, 2019
Roland R. Griffiths, Ethan Hurwitz, Alan K. Davis et al.
249 citations
Experiences interpreted as personal encounters with God, whether occurring naturally or after taking psychedelic drugs, share striking similarities. In an online survey of over 4,200 people, those who had a nondrug encounter most often called it God, whereas those who had a psychedelic encounter most often called it Ultimate Reality. Regardless of origin, most participants vividly remembered the encounter as involving a conscious, benevolent, intelligent, sacred, eternal, and all-knowing presence. About half of all encounters met criteria for a complete mystical experience. More than two-thirds of self-identified atheists no longer identified as atheist afterward.
Journal of Humanistic Psychology
April 1, 2004
Huston Smith, Charles S. Grob, Robert L. Jesse et al.
29 citations
Huston Smith revisits his influential article on whether drugs have religious import. Drawing on personal experience, he discusses how psychedelic experiences have shaped religious traditions and contemplative practices, citing the ancient Vedic tradition, the Eleusinian mysteries, and the contemporary Native American Church. He reflects on why the 1960s psychedelic movement failed to produce lasting social change, critiques current drug policy and culture, and emphasizes the role of elders in society.
Psychedelic Medicine
May 16, 2025
Roland R. Griffiths, William A. Richards, Robert L. Jesse et al.
14 citations
In clergy from various world religions who had never used psychedelics, two supported psilocybin sessions (20 mg/70 kg, then 20 or 30 mg/70 kg) led to sustained positive changes in religious practices, attitudes about their religion, and effectiveness as a religious leader, as well as in non-religious attitudes, moods, and behavior, compared with a waitlist control group. At 16‑month follow‑up, 96% rated at least one experience among the top five most spiritually significant of their lives, 42% rated it the single most profound, and 79% reported positive effects on daily sense of the sacred. No serious adverse events occurred, though 46% rated an experience among the top five most psychologically challenging of their lives.
Journal of Psychoactive Drugs
January 1, 2024
Kelan Thomas, Robert L. Jesse, Nicky J. Mehtani et al.
4 citations
Policymakers are increasingly using clinical trial data to justify deprioritizing, decriminalizing, or legalizing psychedelic substances, but personal possession limits written into law often lack scientific grounding. This commentary argues that allowable amounts should be based on moderate-high doses shown safe and effective in clinical trials, common naturalistic use, and dose-equivalence studies. The authors provide a table of evidence-informed moderate-high doses for seven psychedelics to guide consistent and equitable policy limits, aiming to replace arbitrary thresholds with scientifically justified ones.
Drug and Alcohol Dependence
December 16, 2014
Frederick S. Barrett, Matthew P. Bradstreet, Jeannie‐marie Leoutsakos et al.
4 citations
No Summary
Drug and Alcohol Dependence
December 16, 2014
Theresa M. Carbonaro, Frederick S. Barrett, Matthew P. Bradstreet et al.
3 citations
No Summary