A systematic review and meta-analysis examined how psychedelics and MDMA affect cognitive performance during acute drug effects and the sub-acute (afterglow) window. Acute psychedelic use impairs attention and executive function, while MDMA primarily impairs memory, leaving executive functions and attention unaffected. During the sub-acute period (at least 24 hours after acute effects subside), executive functioning and creativity may be increased following psychedelics, but no such effects were observed for MDMA. These findings can inform harm reduction recommendations for recreational use and support differential therapeutic approaches for psychedelics and MDMA.
People who have used psychedelics such as psilocybin, LSD, or ayahuasca a mild to moderate number of times over their lives show broadly equivalent neuropsychological performance to non-users, but with a modest advantage in executive functions, particularly cognitive flexibility as measured by the Wisconsin Card Sorting Test (WCST). In matched-pair analyses, users performed better on the WCST, and dose-response analyses within the user group found that greater lifetime use was positively associated with fewer total errors, perseverative responses, perseverative errors, non-perseverative errors, and more conceptual level responses. The study did not find any negative associations between sporadic psychedelic use and cognition.