People who used MDMA (ecstasy) and met criteria for substance abuse or dependence showed greater cognitive deficits than those who used the drug recreationally. MDMA users overall performed worse on memory and executive function tasks compared to non-users. The findings suggest that clinically dysfunctional MDMA use, rather than occasional recreational use, is linked to cognitive impairment.
Moderate MDMA use does not cause lasting cognitive impairments beyond those linked to general heavy drug use, but using multiple drugs together may lead to dose-related problems in temporal and frontoparietal brain function. Marijuana use appears especially harmful. The cause-effect relationships remain uncertain.