The effects of acute and repeated adolescent MDMA exposure on behavior, cognition, and the monoamine neurotransmitter systems: A review of human and pre-clinical research

3,4-methylenedioxymethamphetamine (MDMA) is a psychomotor stimulant drug. While much research has examined the effects of MDMA in adults, relatively little research has examined the effects in adolescents. Adolescence is a unique period of brain development, and the effects of MDMA may differ in adolescents compared to adults. In this review, we summarize the literature on the effects of acute and repeated adolescent MDMA exposure on behavior, cognition, and the monoamine neurotransmitter systems in adolescent rodents and humans. PubMed was searched using predefined criteria, resulting in the evaluation of 1012 articles. Fifty-four articles met the search criteria, 48 of which examined the effects of adolescent MDMA exposure in adolescent rodents and 6 of which examined the effects in adolescent humans. Studies measuring the effects of acute MDMA exposure examine outcome measures following a single exposure to MDMA, and studies measuring the effects of repeated MDMA exposure examine outcome measures at some point following multiple exposures to MDMA. Exposure to acute higher doses of MDMA generally increases locomotor activity and causes impairments in the serotonin neurotransmitter system. The literature on the effects of repeated adolescent MDMA exposure shows conflicting results, and the findings are dependent on the dosing, testing environment, and timing of testing following MDMA exposure. There is a lack of literature examining the effects of MDMA in adolescent females. More research is needed with consistent exposure and dosing paradigms and in female subjects to better understand the effects of adolescent MDMA exposure.