R.R. Griffiths, et al.

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

Review by Sally Paddock, 2008

Griffiths, R.R.; Richards, W.A.; Johnson, M.W.; McCann, U.D.; Jesse, R. 2008. “Mystical-type experiences occasioned by psilocybin mediate the attribution of personal meaning and spiritual significance 14 months later." Journal of Psychopharmacology 22(6): 621-632.

Psilocybin, known to be a psycho-active ingredient used for centuries in the context of religious and/or recreational environments, has had its effects often reported anecdotally but has only infrequently been studied in a scientific, empirically-controlled environment. Following the heels of research conducted internationally (Switzerland and Germany), this study sought to measure the immediate and long-term effects of orally ingested psilocybin on healthy, hallucinogen-na´ve adults. The chemical, like other hallucinogens, is known to initiate “acute subjective effects [which] include robust changes in perception, cognition, affect, volition and somaesthesia.” (621)

The double-blind study recruited volunteers by advertising for a study which would involve altered “states of consciousness brought about by a naturally occurring psychoactive substance used sacramentally in some cultures.” (622) Thirty-six people participated and were told that they would participate in two or three 8-hour sessions, conducted over 2-month intervals, in which they would receive the psychoactive drug at least once. All participants reported at least minimal past participation in religious or spiritual activities, they ranged in age from 24-64 yrs, and 97% were college graduates.

Before the study was conducted, participants completed a range of personality, suggestibility, quality of life, mysticism-scale, faith-maturity scale, and positive-negative affect inventories. Each inventory was also completed immediately after the drug effects had subsided, 2-months after the study was completed and 14 months after the study was completed. In addition to the original inventories, subjects were asked to fill out the Persisting Effects Questionnaire, including questions which asked, on a scale, how meaningful the experience was in relation to other life experiences, to what degree the experience was spiritually significant, and if the experience led to a lasting change for the subject’s feeling of well-being or life-satisfaction.

After the 14-month follow-up sessions were conducted, 67% of the volunteers rated the psilocybin experience as “being among the five most personally meaningful experiences of their lives;” 17% of the volunteers reported that the experience was “the single most spiritually significant experience;” and 64% of the volunteers reported that they had an increased sense of well-being including “positive changes in attitudes, mood, altruism and other behaviour.” (630) Of the inventories completed before and after the study, only the inventories of mystical-scale experiences showed significant difference. Also of significance was that none of the subjects reported feeling any negative consequences or side-effects due to the experience.

This study, in producing reliable, empirical and confirmable results, and with subjects reporting no negative consequences, paves the way for other researchers to continue studying the positive – both at an individual and potentially social level – effects of psilocybin and other hallucinogenic-agents, government-policy permitting. Hopefully, studies like this one will also act to chip away at the negative stereotypes that surround hallucinogenic use; provide a framework where individuals and groups can learn how to use them in a healthy, positive manner; and also suggest explanations of how hallucinogens promote spiritual experiences and how religious traditions, in turn, can learn how their own social structures have been and can be effected by spiritual experiences – psychoactively induced or not.

Although the various personality measures of the participants were not predictive of their mystical, meaningful experience of psilocybin, it should be emphasized that the study itself possibly attracted a very narrow range of participants – not everyone would be willing to sign up as a volunteer to undergo an altered state of consciousness. Indeed, the researchers report that, despite other differences, the volunteer group was “relatively homogeneous,” measuring similar measures of “low neuroticism and negative affect and high extroversion, openness, agreeableness and spirituality.” (630) These common variables, coupled with the fact that all subjects had reported to have participated in previous spiritual activities, should be taken into consideration when conducting future research. The ethics of conducting psychoactive-related research on participants who are not initially receptive to the idea, however, would be complicated. Public support and popular awareness of research results will likely have to be published before such comprehensive studies can take place.

Of note in the study, as well, is that each subject participated in 4 preliminary sessions with research monitors, building rapport and trust. While ingesting the agent, subjects were also encouraged to focus their attention inward rather than perform tasks. This positive, interpersonally encouraging environment should be kept in mind by future researchers and by future recreational and religious users of hallucinogens as a positive, subjective experience of the psychoactive agent might also be conditioned by a positive external environment.