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. 2016 Dec;30(12):1268-1278.
doi: 10.1177/0269881116662634. Epub 2016 Aug 30.

Survey study of challenging experiences after ingesting psilocybin mushrooms: Acute and enduring positive and negative consequences

Theresa M Carbonaro  1 , Matthew P Bradstreet  1 , Frederick S Barrett  1 , Katherine A MacLean  1 , Robert Jesse  1   2 , Matthew W Johnson  1 , Roland R Griffiths  3   4
Affiliations

Survey study of challenging experiences after ingesting psilocybin mushrooms: Acute and enduring positive and negative consequences

Theresa M Carbonaro et al. J Psychopharmacol. 2016 Dec.

Abstract

Acute and enduring adverse effects of psilocybin have been reported anecdotally, but have not been well characterized. For this study, 1993 individuals (mean age 30 yrs; 78% male) completed an online survey about their single most psychologically difficult or challenging experience (worst "bad trip") after consuming psilocybin mushrooms. Thirty-nine percent rated it among the top five most challenging experiences of his/her lifetime. Eleven percent put self or others at risk of physical harm; factors increasing the likelihood of risk included estimated dose, duration and difficulty of the experience, and absence of physical comfort and social support. Of the respondents, 2.6% behaved in a physically aggressive or violent manner and 2.7% received medical help. Of those whose experience occurred >1 year before, 7.6% sought treatment for enduring psychological symptoms. Three cases appeared associated with onset of enduring psychotic symptoms and three cases with attempted suicide. Multiple regression analysis showed degree of difficulty was positively associated, and duration was negatively associated, with enduring increases in well-being. Difficulty of experience was positively associated with dose. Despite difficulties, 84% endorsed benefiting from the experience. The incidence of risky behavior or enduring psychological distress is extremely low when psilocybin is given in laboratory studies to screened, prepared, and supported participants.

Keywords: Psilocybin; adverse effects; bad trip; hallucinogen; human; psychedelic; survey.

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Conflict of interest statement

Declaration of Conflicting Interest

The authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: RRG is a member of the Board of Directors of the Heffter Research Institute. RJ is convener of the Council on Spiritual Practices.

Figures

Figure 1
Figure 1
Distributions of ratings in response to four questions about how the participant felt in retrospect about their experiences in the context of their full life experience (N = 1993). Bars show percentage of total participants that endorsed each category.
Figure 2
Figure 2
Distribution of participant-rated durations of challenging experiences (N = 1993). Bars show percentage of total participants that endorsed each category.
Figure 3
Figure 3
Percentage of participants endorsing specific strategies that they reported using to attempt to stop the challenging experience (gray bars) (N = 1993) and that they reported having helped substantially to stop the challenging experience (striped bars) (N = 1993). Of the participants 9.1% reported doing nothing to try to stop the experience. The bars sum to more than 100% because most participants (52%) endorsed trying more than one strategy.
See this image and copyright information in PMC

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References

    1. Allen JW, Merlin MD, Jansen KL. An ethnomycological review of psychoactive agarics in Australia and New Zealand. J Psychoactive Drugs. 1991;23:39–69. - PubMed
    1. Baggott MJ, Coyle JR, Erowid E, et al. Abnormal visual experiences in individuals with histories of hallucinogen use: A Web-based questionnaire. Drug Alcohol Depend. 2011;114:61–67. - PubMed
    1. Barrett FS, Johnson MW, Griffiths RR. Validation of the revised Mystical Experience Questionnaire in experimental sessions with psilocybin. J Psychopharmacol. 2015;29:1182–1190. - PMC - PubMed
    1. Beug MW, Bigwood J. Psilocybin and psilocin levels in twenty species from seven genera of wild mushrooms in the pacific northwest, USA. J Enthopharmacol. 1982;5:271–285. - PubMed
    1. Bigwood J, Beug MW. Variation of psilocybin and psilocin levels with repeated flushes (harvests) of mature sporocarps of psilocybe cubensis (Earle) Singer. J Enthopharmacol. 1982;5:287–291. - PubMed

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