Neurocognitive impairments in MDMA and other drug users: MDMA alone may not be a cognitive risk factor

Abstract

Background: MDMA (3,4-methylenedioxymethamphetamine; “Ecstasy”) is an amphetamine derivative with mild hallucinogenic and stimulant qualities. MDMA leads to serotonin (5-hydroxytryptamine; 5-HT) neurotoxicity and has been linked to cognitive impairments. It remains unclear whether these impairments are due to MDMA versus other drug use. Method: Neurocognitive functioning was measured in a sample of abstinent polydrug users (n = 52) with a range of MDMA use and healthy nondrug controls (n = 29). Participants completed a comprehensive neuropsychological battery and self-report measures of drug use. Results: Polydrug users performed worse than controls on spatial span and spatial working memory (ps < .05). Among polydrug users, lifetime marijuana use significantly predicted verbal learning and memory performance (p < .01), while MDMA use was not predictive of cognitive impairment. Conclusions: This study and our previous report (Hanson, Luciana, & Sullwold, 2008) suggest that moderate MDMA use does not lead to persistent impairments above and beyond that associated with generally heavy drug use, but polydrug use may lead to dose-related temporal and frontoparietal dysfunction. Marijuana use may be particularly problematic. Cause–effect relations are unclear.

Keywords:

• 3,4-Methylenedioxymethamphetamine
• Ecstasy
• Cognition
• Drug use
• Serotonin
• Memory
• Executive function
• Marijuana

This project was supported by the University of Minnesota Graduate School Doctoral Dissertation Research Grant, the National Institute of Mental Health (NIMH) Neurobehavioral Aspects of Personality & Psychopathology T32 Pre-Doctoral Traineeship at the University of Minnesota Department of Psychology, and the National Institute on Alcohol Abuse and Alcoholism (NIAAA) Alcohol Research in the Science/Practitioner Model T32 Post-Doctoral Fellowship at San Diego State University awarded to Karen L. Hanson and by the McKnight Land-Grant Professorship awarded to Monica Luciana by the Office of the Vice President for Research at the University of Minnesota. We would like to thank David Ansari, Danielle Cheek, Patricia Dickmann, Catalina Hooper, Melissa Saari, Athenais Snaza, Kristin Sullwold, and Dustin Wahlstrom for their assistance with data collection and management.