Even low doses of Ecstasy may be associated with a decline in language-related memory, according to a report in the June issue of Archives of General Psychiatry, one of the JAMA/Archives journals.
Ecstasy is an illicit recreational drug popular among young people, according to background information in the article. Research in both humans and animals suggests that the drug can harm the brain. Ecstasy may damage nerve cells that respond to the hormone serotonin, which is involved in mood, thinking, learning and memory.
Thelma Schilt, M.Sc., of the Academic Medical Center of the University of Amsterdam, the Netherlands, and colleagues recruited 188 volunteers (average age 22) who had not used Ecstasy but reported that they were likely to try it soon. Within three years of the initial evaluations, which took place between April 2002 and April 2004, 58 individuals began using Ecstasy. They were compared with 60 individuals who had the same age, sex and intelligence score but who did not use Ecstasy during the follow-up period. All participants took tests that assessed various types of memory--including attention, verbal memory for words and language, and visual memory for images--at the beginning and end of the study. Verbal memory was tested by memorizing a series of 15 words and repeating them immediately and again 20 minutes later.
"At the initial examination, there were no statistically significant differences in any of the neuropsychological test scores between persistent Ecstasy-naïve subjects and future Ecstasy users," the authors write. "However, at follow-up, change scores on immediate and delayed verbal recall and verbal recognition were significantly lower in the group of incident Ecstasy users compared with persistent Ecstasy-naïve subjects. There were no significant differences on other test scores."
In contrast to other studies, which have suggested that Ecstasy affects women more than men, there was no difference in the drug's effect between the sexes. Overall, test scores remained within the normal range for the general population.
The fact that Ecstasy appeared to affect only verbal memory points to specific brain areas and chemicals that may be affected by the drug, the authors note. "The main underlying factor seems to be a depletion of serotonin in Ecstasy users, a depletion that might be reversible," they write. "Serotonin is involved in several cognitive functions but might be especially relevant to learning and memory."
"In conclusion, our data indicate that low doses of Ecstasy are associated with decreased verbal memory function, which is suggestive for Ecstasy-induced neurotoxicity," the authors conclude. "Further research on the long-term effects of Ecstasy as well as on the possibility of additive effects of Ecstasy use on aging of the brain is needed."
(Arch Gen Psychiatry. 2007;64:728-736. Available pre-embargo to the media at www.jamamedia.org.)
Editor's Note: This study was supported by a grant from the Netherlands Organization for Health Research and Development as part of their Addiction Program. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.