VIENNA — Even a few low doses of the drug ecstasy were associated with a decline in verbal memory function in first-time users, Thelma Schilt said at the annual congress of the European College of Neuropsychopharmacology.
And carriers of the methionine allele of the catechol-O-methyltransferase (COMT) gene polymorphism proved far more sensitive to this adverse effect than were people who possessed the valine allele, added Ms. Schilt of the Am-sterdam Institute for Addiction Research and the University of Amsterdam.
Ecstasy (3,4-methylenedioxymethamphetamine), also known as MDMA, is an inexpensive illicit recreational drug. Data from animal studies suggest ecstasy is neurotoxic, producing long-term damage to the distal axons of serotonergic neurons.
Cognitive deficits have been documented in recreational users. However, such studies have been either cross-sectional or retrospective, and have mostly involved heavy users of ecstasy and multiple other drugs, including cocaine, alcohol, cannabis, and amphetamines. For this reason, Ms. Schilt and her coinvestigators performed a prospective observational cohort study in 188 ecstasy-naive subjects as part of the larger Netherlands XTC Toxicity Study. Participants, whose mean age was 22 years, were recruited at dance clubs and universities. They had to indicate an interest in trying ecstasy in the future, have a history of only minimal exposure to other recreational drugs, and undergo baseline neuropsychologic testing and brain imaging.
Over 11 months, 58 subjects took ecstasy. Their use was modest: a mean cumulative dose of 3.2 tablets and a median of 1.5. They underwent neuropsychologic testing roughly 12 weeks after their most recent use, as did a matched group of 60 subjects who were ecstasy naive.
At baseline, the two groups had similar neuropsychologic test scores. However, at follow-up the ecstasy users had significantly lower scores on immediate and delayed verbal recall and verbal recognition. Other cognitive domains were unaffected.
“The changes are small. You would not notice in everyday life that their memory had declined,” Ms. Schilt stressed.
Further follow-up will show whether the deficits remain after longer periods of abstinence. Also worthy of further study is the possibility that ecstasy accelerates the decline in verbal memory that's part of the normal aging process. Answers to these questions will have a bearing on ongoing clinical studies exploring the use of MDMA to facilitate psychotherapy, she added.
Animal studies suggest ecstacy produces long-term damage to the distal axons of serotonergic neurons. MS. SCHILT