MDMA (ecstasy) produces prosocial effects such as sociability and empathy, consistent with user reports. In rodents, MDMA increases passive prosocial behavior and social reward while reducing aggression, possibly through serotonin 1A receptor-mediated oxytocin release interacting with vasopressin receptor 1A. In humans, MDMA raises plasma oxytocin, fosters feelings of social affiliation, reduces recognition of negative facial expressions (cognitive empathy), blunts responses to social rejection, and enhances responses to others' positive emotions (emotional empathy) while increasing social approach. These neurobiologically complex prosocial effects likely motivate recreational ecstasy use.
Heavy ecstasy use is associated with some lowering of higher-level cognitive functions, but not with substantial cognitive dysfunction. A study comparing 45 abstinent ecstasy polydrug users, 48 cannabis polydrug users, and 40 legal drug users found no clear differences between groups on tests of attention, memory, and executive function. Lifetime dose of ecstasy was inversely linked to verbal memory performance, and a combination of drug-use variables, including ecstasy, predicted attention and working memory, though each factor explained only 1–6% of the variance in scores.