Experts have warned for years that the "rave" drug taken by an estimated 500,000 young people every weekend could cause irreversible changes in the brain, raising the risk of long-term personality change and chronic depression. The warnings were based on animal studies and on the drug's chemical effects in humans.
Now researchers in the United States have obtained the first visual evidence of the drug's effect on the brain. Scans were taken of 14 people, nine men and five women, who had used the drug on average more than six times a month for more than four years. Their average age was 26 and their use ranged from once a month to every other day.
Ecstasy has been suspected of damaging the brain cells that produce the brain chemical serotonin, an important controller of mood which is linked with depression and personality disorders. The scans, when compared with those of people who had never used the drug, showed that Ecstasy appeared to destroy the axons - or nerve fibres - that transmit nerve signals between the cells.
Before being given a brain scan, the drug-users were injected with a radioactive tracer chemical that is absorbed by the axons in the serotonin- producing part of the brain. This showed that significantly less of the chemical, coloured yellow on the scans, was taken up by the axons of the drug-users than by those of subjects who did not take drugs.
The scans were more abnormal in those who had taken the drug more often. Although some had not used Ecstasy for several years, their scans were no better than those of current users, suggesting that whatever damage is caused may be irreversible.
Writing in The Lancet , the researchers from the National Institute of Mental Health in Bethesda, Maryland, say: "Our data suggest that people who use MDMA [Ecstasy] as a recreational drug may unwittingly be putting themselves at risk of developing brain 5-HT [serotonin] neural injury." They add that the consequences are unclear "but may include depression, anxiety, memory disturbance and other neuropsychiatric disorders".
Ecstasy has been linked with about 70 deaths since 1987. Concern in Britain grew after the death of Leah Betts, who collapsed during her 18th birthday party in 1995.
Some experts have argued that the number of deaths is small in relation to the number of users, but the latest findings confirm earlier suggestions that Ecstasy's long-term effects are grim. Studies in rats and monkeys have shown that the drug damages the serotonin receptors in the brain and a study of 30 regular users of Ecstasy found that they had lower levels of serotonin in their cerebro-spinal fluid.
There have been reports of regular users of Ecstasy suffering mental breakdowns and the British Medical Journal warned in an editorial two years ago that the drug might lead to psychiatric abnormalities. Psychiatrists said damage might be slow and insidious and problems such as major depression could take years to appear.
One study in Sheffield showed that a single dose of Ecstasy equivalent to that taken by a human caused considerable degeneration in the brains of rats. An American study of squirrel monkeys showed that although damaged nerve fibres did grow back, they were abnormal.Reuse content