People sometimes argue that MDMA increases serotonin, so how can a serotonin antagonist act like an antidepressant. I have never tried it nor do I have any desire to, but how does MDMA make one feel good, high, emphatic, etc, if serotonin makes one feel apathetic, depressed, dull, etc? It seems to confuse people and fuel the theory that low serotonin causes depression.