Heavy ecstasy (MDMA) use is associated with lasting verbal memory deficits and elevated psychological symptoms even after more than 2.5 years of abstinence, while reduced serotonin transporter availability in the brain may partially recover when use stops. In a longitudinal study comparing current ecstasy users, ex-users, polydrug controls, and drug-naive controls over two years, ex-users showed the worst verbal memory and highest symptom scores, with no improvement over time. Current users' memory and symptoms did not worsen during continued use. Serotonin transporter availability in the midbrain recovered as current users reduced MDMA use, but this recovery may not reflect neuronal integrity. Pre-existing differences cannot be ruled out as an alternative explanation.
Current and former ecstasy users show no higher rates of most mental disorders than non-users, except for substance-related disorders. Substance-induced cognitive, affective, and anxiety disorders were more common among ecstasy users than polydrug controls. Lifetime ecstasy dependence occurred in 73% of users. Over half of former users and nearly half of current users met criteria for substance-induced cognitive disorders at testing. Higher lifetime doses of ecstasy predicted cognitive disorders. Pre-existing depression or anxiety did not explain ecstasy use, as these disorders were not more frequent in users. Cognitive problems persisting after more than five months of abstinence may result from MDMA's serotonergic neurotoxicity.