Adverse effects include addiction, memory problems, paranoia, difficulty sleeping, teeth grinding, blurred vision, sweating, and a rapid heartbeat. Deaths have been reported due to increased body temperature and dehydration. Following use people often feel depressed and tired. MDMA acts primarily by increasing the activity of the neurotransmitters serotonin, dopamine, and noradrenaline in parts of the brain. It belongs to the substituted amphetamine classes of drugs and has stimulant and hallucinogenic effects.
MDMA is illegal in most countries and, as of 2018, has no approved medical uses. Limited exceptions are sometimes made for research. Researchers are investigating whether MDMA may assist in treating severe, treatment-resistant posttraumatic stress disorder (PTSD) with phase 3 clinical trials to look at effectiveness and safety expected to begin in 2018. In 2017 the FDA granted MDMA a breakthrough therapy designation for PTSD, meaning if studies show promise, a review for potential medical use could occur more quickly.
MDMA was first developed in 1912 by Merck. It was used to improve psychotherapy beginning in the 1970s and became popular as a street drug in the 1980s. MDMA is commonly associated with dance parties, raves, and electronic dance music. It is often sold mixed with other substances such as ephedrine, amphetamine, and methamphetamine. In 2016, about 21 million people between the ages of 15 and 64 used ecstasy (0.3% of the world population). This was broadly similar to the percentage of people who use cocaine or amphetamines, but fewer than for cannabis or opioids. In the United States, as of 2017, about 7% of people have used MDMA at some point in their life and 0.9% have used in the last year.