WEDNESDAY, April 6 (HealthDay News) -- Long-term users of the illegal drug ecstasy are at risk for brain damage, warns a new study.

Brain scans showed an approximate 10 percent shrinkage in the volume of the hippocampus and a lower proportion of overall gray matter among long-term ecstasy users, the researchers found.

Previous research has suggested that people who use ecstasy can develop serious memory problems, so a team of Dutch researchers decided to investigate whether the drug caused structural changes in the brain.

They used MRI scans to measure the volume of the hippocampus in 10 men in their mid-20s who were long-term ecstasy users and seven men in the same age group who had never used the drug.

The hippocampus is the area of the brain responsible for long-term memory.

On average, the ecstasy users had not taken the drug for more than two months before undergoing the MRI scans, but had taken an average of 281 ecstasy tablets over the previous six and half years.

The scans revealed that ecstasy users had an average of 10.5 percent less hippocampal volume than non-users. The users also had an average 4.6 percent lower overall proportion of grey matter in the brain, which suggests that the effects of ecstasy may not be limited to the hippocampus.

"Taken together, these data provide preliminary evidence suggesting that ecstasy users may be prone to incurring hippocampal damage, following chronic use of this drug," the researchers wrote in a journal news release.

The study appears online in the Journal of Neurology Neurosurgery and Psychiatry.

The researchers noted that atrophy of the hippocampus "is a hallmark for diseases of progressive cognitive impairment in older patients, such as Alzheimer's disease."

More information

The U.S. National Institute on Drug Abuse has more about ecstasy.