Reward-related decision-making deficits and elevated impulsivity among MDMA and other drug users

The recreational drug, 3,4-methylenedioxymethamphetamine (MDMA; 'Ecstasy'), is a synthetic amphetamine derivative and a serotonin neurotoxin. MDMA use is associated with cognitive dysfunction and impulsivity, but since polydrug abuse is common among users it is difficult to attribute these problems specifically to MDMA. Moreover, few studies have examined reward-related cognitive processes. Our aim was to examine reward-related decision-making and impulsivity among MDMA users while controlling for polydrug use via appropriate comparison groups.

We examined decision-making [Iowa Gambling Task, IGT; Bechara, A., Damasio, A.R., Damasio, H., Anderson, S.W., 1994. Insensitivity to future consequences following damage to human prefrontal cortex. Cognition 50, 7-15], self-reported impulsivity (Multidimensional Personality Questionnaire-Brief Form [constraint subscale]; Barratt Impulsiveness Scale; Zuckerman Sensation Seeking Scale), and drug use among 22 abstinent MDMA users, 30 other drug users, and 29 healthy non-drug controls.

MDMA and other drug users showed comparable patterns of decision-making and impulsivity. However, both drug groups demonstrated poorer IGT performance and elevated self-reported impulsivity relative to controls. Poorer decision-making was related to heavier drug use in the past year, heavier weekly alcohol use, and meeting lifetime substance use disorder (SUD) criteria for more drug classes. Elevated impulsivity was associated with heavier drug use, heavier weekly alcohol use, more lifetime SUDs, and higher self-reported depression levels.

These findings contradict the idea that MDMA is specifically associated with deficient decision-making. Drug users, in general, may be at risk for decision-making deficits and elevated impulsivity. Such behaviors may represent trait factors that lead to the initiation of drug and alcohol use, and/or they may represent behavior patterns that are exacerbated by extensive use.