Ecstasy (MDMA) users’ brains show signs of poorer processing when working on challenging cognitive tasks when compared with the brains of people who have never used the drug, according to a study published in the Journal of Psychopharmacology.

MDMA works by stimulating the brain’s release of several neurotransmitters, particularly serotonin. Animal research has shown that sustained MDMA use can cause damage to parts of the brain related to serotonin production and transmission. Because these serotonin receptors are especially densely located in the prefrontal cortex, the region of the brain responsible for much cognitive processing, there has been concern that prolonged MDMA use may lead to impaired cognitive functioning over time.

A study led by C. A. Roberts, of the University of Liverpool, sought to address this issue using functional MRI (fMRI) technology to compare the patterns of brain activity while performing a difficult cognitive task in 20 MDMA users and 20 control subjects who had never used MDMA. The MDMA users had taken the drug at least 11 times.

A fMRI procedure recorded the intensity of activity in the prefrontal cortex while study participants were completing two intelligence tests. Greater activity is thought to be related to greater cognitive effort.

Results showed that although both MDMA users and nonusers performed similarly well on the tests, the users’ prefrontal cortexes were significantly more active. This pattern indicates that the users brains needed to work harder in order to achieve the same results. Elevation of prefrontal cortex activity was the most extreme among those who had used the largest amounts of MDMA over time, and among those who had used it the most recently.

The study authors concluded that MDMA use had probably caused damage to the serotonin receptors in the prefrontal cortex, which in turn made cognitive processing more difficult. They also concluded that these effects were likely to be cumulative, increasing over time with repeated MDMA use. The observation that the cognitive effects were more severe in those with the most recent history of MDMA use suggests that the brain my recover from this damage over time.

These effects appeared to be unique to MDMA use, as neither alcohol nor marijuana use was associated with differences in brain functioning in these areas.

These results suggest that MDMA users should be aware of the potential long-term cognitive impacts of using the drug. Given that the effect appears to be cumulative and may be reduced over time, stopping or limiting additional use may help to minimize neural damage among current users.