ABSTRACT
Previous studies have investigated challenging, difficult, or distressing classic psychedelic experiences, but little is known about the prevalence and associations of such experiences. Using nationally representative data of the US adult population (N = 2822), this study examined the prevalence and associations of challenging, difficult, or distressing experiences using classic psychedelics, in a subsample of respondents who reported lifetime classic psychedelic use (n = 613). Of the 613 respondents who reported lifetime classic psychedelic use, the majority of them (59.1 %) had never had a challenging, difficult, or distressing experience using a classic psychedelic, but 8.9 % of respondents reported functional impairment that lasted longer than one day as a result of such experiences. Notably, 2.6 % reported seeking medical, psychiatric, or psychological assistance in the days or weeks following their most challenging, difficult, or distressing classic psychedelic experience. In covariate-adjusted regression models, co-use of lithium, co-use of other mood stabilizers, and six set and setting variables (no preparation, disagreeable physical environment, negative mindset, no psychological support, dose was too large, major life event prior to experience) were associated with the degree of difficulty; and co-use of lithium, co-use of other mood stabilizers, and three set and setting variables (negative mindset, no psychological support, major life event prior to experience) were associated with overall risk of harm. In summary, this study provides insight into the prevalence and associations of challenging, difficult, or distressing classic psychedelic experiences. The findings broadly correspond with findings from previous studies and can inform harm reduction efforts and future experimental research designs.