Abstract
BACKGROUND: Research on psilocybin has become increasingly popular during the current psychedelic renaissance, which began in the early 1990s. Psilocybin's effects on mental health are promising and there are ongoing efforts to investigate its clinical implementation and its effects on cognition. AIMS: The purpose of this study is to report trends in publications, methods, and findings from research examining the effects of psilocybin on cognition and creativity in adults. METHODS: We conducted an Open Science Framework preregistered scoping review, guided by the JBI Manual for Evidence Synthesis, on literature pertaining to psilocybin's effects on cognition and creativity. RESULTS/OUTCOMES: In the 42 included studies, psilocybin was primarily administered orally (83%) in a bodyweight-adjusted manner (74%) to healthy participants (90%). Of the few studies that explicitly reported safety outcomes (26%), only one reported serious adverse reactions. During the acute phase post-intake (i.e., minutes to hours), macrodoses tended to impair cognitive performance and creativity, whereas microdoses tended toward creative enhancement. The few macrodosing studies that included post-acute measures (i.e., 1-85 days) reported primarily null but some positive effects. CONCLUSIONS/INTERPRETATION: This scoping review identified a time-based variation of psilocybin macrodosing effects on cognition and creativity, in which impairment may be observed early post-intake but withdraw over time, and some positive effects may emerge afterward. These findings are limited by methodological concerns and inadequate assessment of long-term effects. We therefore recommend that future psilocybin research be conducted according to existing guidelines and include well-validated measures of cognition and creativity at multiple timepoints.