RATIONALE: MDMA or Ecstasy has made a resurgence in popularity and the majority 
of users consist of teenagers and adolescents. Therefore, it is important to 
determine whether MDMA causes long-term damage and what this damage entails. 
There is an ongoing debate about possible neurocognitive changes in 
3,4-methylenedioxymethamphetamine (MDMA) users related to MDMA's neurotoxic 
potential. Multiple neuroimaging studies have shown that Ecstasy use leads to 
lower serotonin transporter (SERT) availability in multiple brain regions. This 
may express itself in a loss of cognitive functions like memory, attention and 
executive function. However, there is increasing evidence reporting that MDMA's 
induced serotonergic adaptations are reversible over time. The question we thus 
address is whether the recovery of SERT function predicts a recovery of 
cognitive function.
OBJECTIVES: This review aims to investigate MDMA's long-term effects on SERT 
availability and cognitive functioning.
METHODS: A literature search was performed in PubMed. Studies that investigated 
the effects of MDMA on both SERT availability and cognitive performance were 
eligible for inclusion.
RESULTS: SERT availability positively correlated with time of abstinence, 
whereas memory performance did not show this correlation, but remained impaired 
in MDMA users. No significant correlation between SERT availability and memory 
function was found (r = 0.232, p = 0.581; r = 0.176, p = 0.677).
CONCLUSIONS: The main findings of this review are that MDMA-use leads to an 
acute decrease in SERT availability and causes an impairment in cognitive 
functions, mostly memory. However, SERT availability recovers with sustained 
abstinence while memory function does not. This suggests that SERT availability 
is not a biomarker for MDMA-induced cognitive impairment and likely also not for 
MDMA-induced neurotoxicity.