Adverse reactions among psychedelic users: Norwegian validation of the Challenging Experience Questionnaire

A Norwegian translation of the Challenging Experience Questionnaire (CEQ) shows strong reliability and validity for assessing adverse psychedelic experiences. An online survey of 729 Norwegian recreational psychedelic users, mostly male (73%) and aged 26–35 (41%), with 90% having used LSD or psilocybin, confirmed the original 7-factor structure. The translated CEQ demonstrated excellent internal consistency (alpha = 0.94) and good overall model fit. The tool also showed factorial invariance across gender and psychiatric status, and convergent validity through relationships between reported difficulty and factors like fear, grief, insanity, and death. This provides Norwegian researchers with a culturally adapted, psychometrically valid tool for evaluating complex adverse reactions to psychedelic use.

Study at a glance

Abstract

Psychedelic drugs, known for their potent psychoactive effects, have gained attention for their potential therapeutic benefits in treating mental disorders. However, distressing experiences induced by psychedelics can lead to adverse long-term effects. To better assess these experiences, we aimed to provide a Norwegian translation and psychometric validation of the Challenging Experience Questionnaire (CEQ), a key tool for evaluating adverse psychedelic experiences. Our study employed an anonymous online survey targeting Norwegian recreational psychedelic users, focusing on their most memorable psychedelic encounter. A sample of 729 participants, predominantly male (73 %) and aged between 26 and 35 years (41 %), with 90 % having used LSD or psilocybin, was analyzed. Half of the participants had completed a university degree, and 48 % reported a diagnosed mental disorder. The CEQ underwent a rigorous seven-stage translation process and was included in the survey to validate the original 7-factor structure. Our findings revealed excellent internal consistency (alpha = 0.94) and robust overall model fit (χ2[278] = 1451.80, RMSEA = 0.076, SRMR = 0.051, CFI = 0.913) for the 7-factor model, with evidence of factorial invariance across gender and psychiatric status. Further, the relationship between reported difficulty and CEQ factors such as fear, grief, insanity, and death underscored its convergent validity. In conclusion, our study confirms the 7-factor structure of the CEQ while demonstrating its reliability and validity. This provides Norwegian researchers with a culturally adapted, psychometrically valid tool for assessing complex adverse reactions to psychedelic use.