Studies using animal models have found considerable evidence of neurological damage resulting from exposure to 3,4- methylenedioxymethamphetamine (MDMA, ecstasy). Yet, studies comparing the cognitive performance of human recreational ecstasy users to ecstasy naïve controls have produced inconsistent results. The present study is a meta-analysis of the published empirical literature on the cognitive sequelae of human recreational ecstasy use. The pooled effect size estimate for combined cognitive domains was statistically significant and moderate in size. Small to large, statistically significant aggregate effect sizes resulted for eight of the nine cognitive ability domains included in the analysis. Moderator analyses suggested that frequent ecstasy use is associated with greater cognitive impairment, cognitive impairment can occur after relatively low amounts of total lifetime cumulative use, and recovery of functioning does not occur within one year post cessation
