Association of a functional polymorphism in the serotonin transporter gene with abnormal emotional processing in ecstasy users.

OBJECTIVE The long-term effects of the use of 3,4-methylenedioxymethamphetamine (MDMA, or Ecstasy) in humans are controversial and unclear. The authors' goal was to assess the contribution of a functional polymorphism in the gene encoding serotonin transporter to changes in emotional processing following chronic Ecstasy use. METHOD They investigated Beck Depression Inventory scores and performance on the Affective Go/No-Go test, a computerized neuropsychological test sensitive to emotional processing, in Ecstasy users and comparison subjects, stratifying the results by serotonin transporter genotype. RESULTS Ecstasy use was associated with higher Beck Depression Inventory score and abnormalities in the Affective Go/No-Go test in individuals with the ss and ls genotype but not those with the ll genotype. CONCLUSIONS Ecstasy users carrying the s allele, but not comparison subjects carrying the s allele, showed abnormal emotional processing. On the basis of a comparison with acute tryptophan depletion, the authors hypothesize that chronic Ecstasy use may cause long-term changes to the serotonin system, and that Ecstasy users carrying the s allele may be at particular risk for emotional dysfunction.