Memory impairment in abstinent MDMA ("Ecstasy") users.
BACKGROUND
Methylenedioxymethamphetamine (MDMA, or "Ecstasy") is a popular recreational drug of abuse that is known to damage brain serotonergic neurons in animals and possibly humans. Few functional consequences of MDMA-induced serotonin (5-HT) neurotoxicity have been identified, either in animals or humans. This study sought to determine whether individuals with a history of extensive MDMA use showed evidence of memory impairment, because brain serotonin has been implicated in mnemonic function.


METHODS
The authors compared 24 abstinent MDMA users and 24 control subjects on several standardized tests of memory, after matching subjects for age, gender, educational level, and vocabulary score (a surrogate of verbal intelligence). The authors also explored correlations between changes in memory function and decrements in CSF 5-hydroxyindoleacetic acid (5-HIAA), which serves as a marker of central 5-HT neural function.


RESULTS
Greater use of MDMA (total milligrams per month) was associated with greater impairment in immediate verbal memory (p < 0.02) and delayed visual memory (p < 0.06). Furthermore, lower vocabulary scores were associated with stronger dose-related effects, with men having greater dose-related deficits than women. Lastly, lower concentrations of CSF 5-HIAA were associated with poorer memory performance.


CONCLUSIONS
Abstinent MDMA users have impairment in verbal and visual memory. The extent of memory impairment correlates with the degree of MDMA exposure and the reduction in brain 5-HT, as indexed by CSF 5-HIAA.
Bolla
K I
KI
Department of Neurology, Johns Hopkins Medical Institutions, Baltimore, MD, USA.
McCann
U D
UD
Ricaurte
G A
GA
D000328:Adult; D005260:Female; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000134:cerebrospinal fluid; D013287:Illicit Drugs / Q000633:toxicity; D008297:Male; D008568:Memory / Q000187:drug effects*; D008875:Middle Aged; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000008:administration & dosage / Q000633:toxicity*; D010364:Pattern Recognition, Visual / Q000187:drug effects; D012044:Regression Analysis; D012701:Serotonin / Q000134:cerebrospinal fluid; D018490:Serotonin Agents / Q000008:administration & dosage / Q000633:toxicity*; D014706:Verbal Learning / Q000187:drug effects
D013287:Illicit Drugs; D018490:Serotonin Agents; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D018817:N-Methyl-3,4-methylenedioxyamphetamine