Thus , the current state of research does not allow for the conclusion that long-term use of MDMA affects decision-making behavior in general .
Different cognitive impairments have been reported as a result of long-term MDMA/ecstasy use .
Increased impulsivity and altered decision-making have been shown to be associated with the development and maintenance of addictive disorders pointing toward the necessity to underst and a potential impairment of decision-making due to MDMA use .
Thus , assessing the long-term effects of MDMA is crucial in order to evaluate its controversially discussed therapeutic use .
The aim of this systematic review was to summarize the scientific literature on potential effects of chronic MDMA use on higher order decision-making processes in humans .
Decision-making impairment is related to serotonin transporter promoter polymorphism in a sample of patients with obsessive–compulsive disorder
OBJECTIVE Decision-making impairment is an important feature of some psychiatric disorders , such as attention-deficit/hyperactivity disorder and substance-use disorders , and is associated with dysfunction of the fronto-subcortical circuit , mainly the orbitofrontal cortex ( OFC ) . Several data reports support significant correlations between decision-making impairment and the serotonin system . Thus , this neurotransmission system may be a major step in some cognitive features , particularly in OCD because serotonin is associated with this disorder . Therefore , the serotonin transporter promoter polymorphism ( 5-HTTLPR ) may be related to the modulation of these cognitive characteristics . In a sample of Caucasian OCD patients , we explored the link between decision-making and the 5-HTTLPR . METHOD We used the  Iowa Gambling Task ( IGT ) to measure decision-making in 49 OCD patients , according to the DSM-IV criteria . All patients were su bmi tted to Y-BOCS , BDI , BAI , the Raven Progressive Matrices , the  Continuous Performance Task  , and the Trail Making Test . We grouped S- and /or Lg-carriers in view of the fact that these act in a nearly dominant way . RESULTS On IGT , S- and /or Lg-carriers had significantly lower scores on the third , fourth , and fifth blocks . These findings were confirmed after adjusting for clinical and cognitive variables . DISCUSSION Inconclusive findings about the link between OCD and 5-HTTLPR may be better eluci date d by study ing OCD subgroups that could be more related in some genetic characteristics . Based on our study , low performance on IGT  is associated with S- and /or Lg-carriers . CONCLUSION Our results corroborate the hypothesis that the pattern of neuropsychological functioning observed in previous studies may constitute a biological marker or heritable endophenotype of OCD
Thus , the current state of research does not allow for the conclusion that long-term use of MDMA affects decision-making behavior in general .
Different cognitive impairments have been reported as a result of long-term MDMA/ecstasy use .
Increased impulsivity and altered decision-making have been shown to be associated with the development and maintenance of addictive disorders pointing toward the necessity to underst and a potential impairment of decision-making due to MDMA use .
Thus , assessing the long-term effects of MDMA is crucial in order to evaluate its controversially discussed therapeutic use .
The aim of this systematic review was to summarize the scientific literature on potential effects of chronic MDMA use on higher order decision-making processes in humans .