Impaired delayed memory function in individuals who stopped using MDMA ("Ecstasy")

L. Reneman, B. Schmand, K de Bruin, W vd Brink, WB Gunning

Departments of Nuclear Medicine, Neurology, Psychiatry, Child-Adolescent Psychiatry, Academic Medical Center, University of Amsterdam, The Netherlands. Phone no: +31 – 20 566 4309 Fax no: +31 – 20 697 6508

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3,4-Methylenedioxymethamphetamine (MDMA), or "Ecstasy", is widely used as an illicit recreational drug of abuse. While the neurotoxic effects of MDMA on serotonin (5-HT) nerve fibers and terminals have been studied extensively, little is known about the functional consequences of MDMA-induced brain 5-HT neurotoxicity. There are studies that suggest that MDMA users have impaired delayed verbal memory. Because these studies have involved subjects who recently used MDMA, it is not clear what the long-term effects are of MDMA use on memory function. The purpose of the current study was to determine whether individuals with a history of extensive MDMA use, but had now stopped using MDMA for at least one year, showed evidence of memory impairment.

Methods

Four groups of subjects were compared: 15 moderate MDMA users ( 50 tablets; "MDMA+-group"), 16 extensive MDMA users who had stopped using MDMA ("ex-MDMA- group"), and 14 control subjects who had never taken MDMA. Subjects were matched for age, gender, and education. Participants agreed to abstain from all recreational drugs for at least 3 weeks before the study, and were asked to undergo drug screening. Delayed verbal memory was assessed using the Rey Auditory Verbal Learning Test (RAVLT)- recall.

Results

Controls and MDMA groups were similar in age, gender and educational level. On delayed recall, extensive MDMA users and ex-MDMA users recalled significantly less words than the controls and moderate MDMA-group

In addition, a negative association was found between the number of MDMA tablets used and performance on the RAVLT-recall (Spearman’s rho: -0.29, p= 0.02). Age, sex, and education had no significant effect on this correlation (p= 0.23, 0.84, and 0.25, respectively).

Conclusions

Consistent with reports of memory problems in previous studies, we observed impairment in delayed verbal memory of current extensive MDMA users. Interestingly, we observed that individuals who stopped using MDMA more than 2 years ago have memory problems. The extent of memory loss correlates with the degree of MDMA exposure.