The popular party drug ecstasy roughs up the dopamine system in monkeys, new research reveals, raising the potential for troubling, long-term side effects in those who use it heavily. The results have some researchers worried that the drug could increase the risk of certain neurological disorders, such as Parkinson's disease.
Ecstasy--which heightens sensations and creates feelings of warmth and empathy--is believed to act by prompting neurons to spurt huge quantities of the neurotransmitter serotonin. But its street name is a cruel misnomer for (±)3,4-methylenedioxymethamphetamine (MDMA): Some researchers believe it causes permanent brain damage. The drug was criminalized in the United States in 1985. Still, it has some supporters, including psychologists who think it can aid therapy for posttraumatic stress disorder.
Now George Ricaurte and colleagues at Johns Hopkins University School of Medicine in Baltimore report in the 27 September issue of Science that, in addition to disrupting serotonin, ecstasy also impacts the dopamine system. Researchers administered the equivalent of a heavy party night's worth of the drug to monkeys. Weeks later, both dopamine and serotonin were depleted in brain tissue samples, and neurons that rely on these chemicals had damage to their axons, projections that send messages to other neurons. That means, the team suggests, that one all-night "rave" might be enough to induce permanent brain damage and make a person more vulnerable to Parkinson's disease, which is caused by a loss of dopamine-producing neurons.
Andy Parrott, head of the Recreational Drugs Research Group at the University of East London, U.K., calls the findings "very worrying." But other researchers, such as cognitive neuroscientist Jon Cole of the University of Liverpool, are skeptical about the Parkinson's risk. So far, he says, "there is only a single case report of parkinsonism related to the use of ecstasy." The Hopkins team says that Parkinson's may not have showed up yet in users because symptoms don't appear until 70% to 80% of brain dopamine has been depleted.