Um, MDMA does not release serotonin to your spine. That's actually a widely believed myth about MDMA (proliferated by a botched psychological study on monkeys by an idiot named George Ricuarte Ricaurte MDMA Research Controversy) Serotonin is a neurochemical, naturally present in your brain. it works with the neurotransmitters in your brain as a serotonin agonist (blocking the reuptake of serotonin in the synaptic cleft, so that the normal amount of SN that is usually recycled by your brain is retained, giving you those 'rolling' feelings of euphoria.)