Ecstasy use and higher-level cognitive functions: weak effects of ecstasy after control for potential confounds

• Published in: Psychological medicine 2008-09, Vol.38 (9), p.1319-1330
• Main Authors: Bedi, G., Redman, J.
• Format: Article
• Language: English
• Subjects: Addictive behaviors; Adult; Adult and adolescent clinical studies; Affect - drug effects; Attention - drug effects; Biological and medical sciences; Cannabis; Cannabis - adverse effects; cognition; Cognition & reasoning; Cognition - drug effects; Cognition Disorders - epidemiology; Cognition Disorders - psychology; Cognitive ability; Cognitive functioning; Cohort Studies; Cross-Sectional Studies; Dose-Response Relationship, Drug; Drug addiction; Drug dosages; Drug use; Dysfunction; Ecstasy; Ecstasy drug; Executive function; Female; Humans; Investigations; Longitudinal studies; Male; Marijuana; Medical sciences; Memory; Memory - drug effects; Memory, Short-Term - drug effects; Multiple drugs; N-Methyl-3,4-methylenedioxyamphetamine - adverse effects; Neuropsychological Tests - statistics & numerical data; polydrug; Predictive Value of Tests; Psychology. Psychoanalysis. Psychiatry; Psychopathology. Psychiatry; Serotonin; Severity of Illness Index; Students - psychology; Substance-Related Disorders - epidemiology; Substance-Related Disorders - psychology; Verbal Behavior - drug effects; Working memory
• ISSN: 0033-2917; 1469-8978
• DOI: 10.1017/S0033291708002730

Although there have been several reports linking ecstasy use with lowered cognitive function, much previous research suffers from substantial methodological limitations. The present study aimed to examine associations between ecstasy use and higher-level cognitive functions, using a larger sample size than most previous research and better controlling for a range of potential confounds. A cross-sectional cohort design assessed 45 currently abstinent ecstasy polydrug users (EP), 48 cannabis polydrug users (CP) and 40 legal drug users (LD). Standardized neuropsychological tests were used to measure attention, verbal, visual and working memory and executive function. Prospective memory function was also assessed. It was not possible to discriminate between groups on the basis of the cognitive functions assessed. Regression analyses showed an inverse association between lifetime dose of ecstasy and verbal memory performance. A combination of drug-use variables, including measures of ecstasy use, contributed to prediction of attention/working memory. However, individual associations were small, explaining 1-6% of variance in cognitive scores. Although the results suggest that heavy use of ecstasy is associated with some lowering of higher-level cognitive functions, they do not indicate a clinical picture of substantial cognitive dysfunction.