MDMA, the active ingredient of ecstasy pills, makes people more inclined to cooperate on tasks and quicker to rebuild trust, according to researchers investigating its use in treating psychological disorders. Scans reveal it increases activity in parts of the brain linked to empathy and social behaviour that helps interpret other people's beliefs and intentions, researchers from King's College London said. This could make it a useful addition to psychotherapy sessions and the drug is currently undergoing medical trials to assess its use in supporting treatment of post-traumatic stress disorder (PTSD). "Understanding the brain activity underlying social behaviour could help identify what goes wrong in psychiatric conditions," said Professor Mitul Mehta from the King's Institute of Psychiatry, Psychology & Neuroscience (IoPPN). While it is possible that making users more helpful and collaborative could lead to them being exploited, Professor Mehta and his team found the drug did not make users gullible. During the study ... participants on MDMA were less likely to cheat their partners than those on the placebo. Where they had previously been cheated ... subjects on MDMA were as likely to act selfishly as those on a placebo, however they were quicker to trust these partners again after a run of cooperation. This was backed up with patterns of brain activity.