MDMA (ecstasy) is a widely misused psychostimulant that increases energy, euphoria, and sociability while also producing distinctive 'entactogen' effects such as feeling close to others and increased empathy. It works by promoting the release and blocking the reuptake of serotonin, dopamine, and norepinephrine. Acute toxic effects include serotonin syndrome, characterized by muscle rigidity, hyperreflexia, and hyperthermia. MDMA metabolism involves two main pathways; one is partially regulated by the polymorphic enzyme CYP2D6, but mechanism-based inhibition after two consecutive doses limits the impact of CYP2D6 genetics on acute toxicity. Metabolism may also contribute to long-term neurotoxic effects through progressive degeneration of the serotonergic system.
A single 75 mg dose of MDMA produces a dissociative state, marked by feelings of depersonalization and derealization, in healthy recreational users. Blocking the 5-HT2 receptor with ketanserin did not prevent this effect, indicating that the 5-HT2 receptor does not mediate MDMA-induced dissociation. Heart rate correlated with the dissociative state after MDMA alone, but not when ketanserin was given, suggesting heart rate changes do not directly cause dissociation. Cortisol levels and MDMA blood concentrations showed no clear relationship with dissociation. The exact neurobiological mechanism remains unknown and may be relevant to MDMA's therapeutic use.