Elevated impulsivity and impaired decision-making cognition in heavy users of MDMA ("Ecstasy").
BACKGROUND
In animal studies, the common club drug 3,4-methylendioxymethamphetamine (MDMA, "Ecstasy") consistently caused a prolonged loss of presynaptic serotonergic neurons, and evidence suggests that MDMA consumption may also affect the human serotonergic system. Serotonin (5-HT) has been implicated in the regulation of impulsivity and such executive functions as decision-making cognition. In fact, MDMA users have shown elevated impulsivity in two studies, but little is known about decision making in drug-free MDMA consumers.


OBJECTIVE
The aim of this study was to examine the cognitive neurotoxicity of MDMA with regard to behavioral impulsivity and decision-making cognition.


METHODS
Nineteen male, abstinent, heavy MDMA users; 19 male, abstinent cannabis users; and 19 male, drug-naïve controls were examined with the Matching Familiar Figures Test (MFFT) as well as with a Go/No-Go Task (GNG) for impulsivity and with a Gambling Task (GT) for executive functioning.


RESULTS
MDMA users showed significantly elevated impulsivity in the MFFT Impulsivity score (I-score), but not in commission errors of the GNG, compared with controls. Cannabis users did not yield altered impulsivity compared with controls. In the GT, MDMA users performed significantly worse than cannabis consumers and controls, whereas cannabis users exhibited the same decision-making capacity as controls. In addition, the I-score as well as the decision-making performance was correlated with measures of MDMA intake. The I-score and the decision-making performance were also correlated.


CONCLUSIONS
These results suggest that heavy use of MDMA may elevate behavioral impulsivity and impair decision-making cognition possibly mediated by a selective impairment of the 5-HT system.
Quednow
Boris B
BB
Department of Psychiatry, University of Zurich, Lenggstrasse 31, CH-8008, Zürich, Switzerland. quednow@bli.unizh.ch
Kühn
Kai-Uwe
KU
Hoppe
Christian
C
Westheide
Jens
J
Maier
Wolfgang
W
Daum
Irene
I
Wagner
Michael
M
D000328:Adult; D019969:Amphetamine-Related Disorders / Q000209:etiology* / Q000523:psychology; D016022:Case-Control Studies; D003071:Cognition / Q000187:drug effects*; D003072:Cognition Disorders / Q000139:chemically induced* / Q000523:psychology; D003657:Decision Making / Q000187:drug effects*; D005715:Gambling; D006213:Hallucinogens / Q000009:adverse effects*; D006801:Humans; D007175:Impulsive Behavior / Q000139:chemically induced*; D008297:Male; D002189:Marijuana Abuse / Q000523:psychology; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000009:adverse effects*; D011795:Surveys and Questionnaires
D006213:Hallucinogens; D018817:N-Methyl-3,4-methylenedioxyamphetamine