The Challenging Experience Questionnaire: Characterization of challenging experiences with psilocybin mushrooms

This online survey study (n=1767) validated a questionnaire that can assess challenging experiences occasioned by psilocybin and other hallucinogens. The authors characterize the phenomenological profile of challenging experiences as consisting of grief, fear, death, insanity, isolation, physical distress, and paranoia and describe the relationship of these factors to meaningfulness, spiritual significance, and change in well-being. This questionnaire presents a useful tool for investigating how acute adverse reactions to psilocybin affect long-term outcomes, such as well-being.


“Acute adverse psychological reactions to classic hallucinogens (“bad trips” or “challenging experiences”), while usually benign with proper screening, preparation, and support in controlled settings, remain a safety concern in uncontrolled settings (such as illicit use contexts). Anecdotal and case reports suggest potential adverse acute symptoms including affective (panic, depressed mood), cognitive (confusion, feelings of losing sanity), and somatic (nausea, heart palpitation) symptoms. Responses to items from several hallucinogen-sensitive questionnaires (Hallucinogen Rating Scale, the States of Consciousness Questionnaire, and the Five-Dimensional Altered States of Consciousness questionnaire) in an Internet survey of challenging experiences with the classic hallucinogen psilocybin were used to construct and validate a Challenging Experience Questionnaire. The stand-alone Challenging Experience Questionnaire was then validated in a separate sample. Seven Challenging Experience Questionnaire factors (grief, fear, death, insanity, isolation, physical distress, and paranoia) provide a phenomenological profile of challenging aspects of experiences with psilocybin. Factor scores were associated with difficulty, meaningfulness, spiritual significance, and change in well-being attributed to the challenging experiences. The factor structure did not differ based on gender or prior struggle with anxiety or depression. The Challenging Experience Questionnaire provides a basis for future investigation of predictors and outcomes of challenging experiences with classic hallucinogens.”

Authors: Frederick S. Barrett, Matthew P. Bradstreet, Jeannie-Marie S. Leoutsakos, Matthew W. Johnson & Roland R. Griffiths

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