There is no convincing evidence that moderate MDMA use is associated with structural or functional brain alterations in neuroimaging measures .
MDMA ( " ecstasy " ) is widely used as a recreational drug , although there has been some debate about its neurotoxic effects in humans .
However , most studies have investigated subjects with heavy use patterns , and the effects of transient MDMA use are unclear .
In this review , we therefore focus on subjects with moderate use patterns , in order to assess the evidence for harmful effects .
Ecstasy use: cognitive deficits related to dosage rather than self-reported problematic use of the drug
Previous research has shown drug-free Ecstasy users to demonstrate selective cognitive impairment However , there seems to be a degree of individual variation in the occurrence of such deficits . The present study aim ed to assess whether these cognitive deficits are related to an awareness of problematic Ecstasy use , or to past drug dosage . Twenty regular Ecstasy users who reported experiencing Ecstasy-related problems were compared with 20 Ecstasy users who had not reported any previous problems . The two groups displayed similar past histories in relation to a range of illicit drugs , and were divided into low , medium and high users . The controls comprised 20 illicit recreational drug users who had never taken Ecstasy . Executive task measures comprised the  Tower of London ( TOL ) , the Wisconsin Card Sorting Task ( WCST ) and spatial working memory . Immediate and delayed word recall , matched verbal recognition and recall and simple reaction time were also included . Both Ecstasy groups performed significantly worse than controls on two executive measures : TOL planning time and spatial working memory score . There were no differences in cognitive impairment between the Ecstasy users who complained of problems and those who did not . In both groups , decrement on executive tasks was demonstrated as a function of previous drug dose . The study confirms that heavy Ecstasy polydrug use may culminate in selective executive deficits . It also demonstrates that two differently self-perceived Ecstasy groups showed similar cognitive impairment , despite only one group complaining of problems . Because all Ecstasy participants also consumed a range of other illicit drugs , the results are reflective of Ecstasy polydrug use in individuals who use Ecstasy as a drug of preference
There is no convincing evidence that moderate MDMA use is associated with structural or functional brain alterations in neuroimaging measures .
MDMA ( " ecstasy " ) is widely used as a recreational drug , although there has been some debate about its neurotoxic effects in humans .
However , most studies have investigated subjects with heavy use patterns , and the effects of transient MDMA use are unclear .
In this review , we therefore focus on subjects with moderate use patterns , in order to assess the evidence for harmful effects .