Recreational drug danger highlighted

Cocaine increases the risk of heart disease

Separate studies into the impact of using cocaine and ecstasy have highlighted the risks associated with recreational use of illegal drugs.

Researchers have discovered that using ecstasy - even in small amounts - can cause an irreversible decline in brain function.

Meanwhile, a second study has found that recreational use of cocaine increases the risk of developing blood clots, and sudden heart disease.

Volunteers in the ecstasy study took part in a battery of tests to assess alertness, attention span, memory, and general intelligence.

My advice to people who take ecstasy is to stop using it

Dr Euphrosyne Gouzoulis-Mayfrank, University of Aachen

They were divided into three groups: regular users of ecstasy, regular users of ecstasy and cannabis and those who used neither drug.

None of the drug users tested was a heavy user, but all had been using over the past two years, and mostly within two to eight weeks of the tests.

Ecstasy users performed no worse than the other participants in terms of alertness, but significantly worse on more complex tasks of memory, learning, and tasks reflecting general aspects of intelligence, such as logical thinking and problem solving.

The higher the use of both ecstasy and cannabis combined, the lower were the performance scores.

However, cannabis use alone did not seem to have the same effect.

Ecstasy damages brain function

The researchers say that the decline in brain function is probably linked to the toxic effect ecstasy has on brain cells - particularly those involved in sending messages around the brain using the chemical serotonin.

Serotonin is known to have a role in memory and information processing.

The researchers warn: "Our data suggest that ecstasy use over a period of months or a few years may cause long term impairment of cognitive performance, even when taken in typical recreational and not necessarily very high doses."

The study follows just days after research which linked ecstasy use to memory damage.

Lead researcher Dr Euphrosyne Gouzoulis-Mayfrank, of the University of Aachen, Germany, told BBC News Online: "My advice to people who take ecstasy is to stop using or decrease the frequency of use."

Cocaine study

In a separate study, a team from the University of Pittsburgh have discovered that even occasional use of cocaine promotes the formation of blood clots.

The risk of thrombosis, similar to the risk of sudden cardiac death, is real and may affect even the first time user of small quantities of the drug

University of Pittsburgh researchers

This could explain why the risk of heart attacks is so much higher in people who use the drug.

The researchers monitored heart rates and blood chemical responses were in 14 volunteers up to two hours after having been given 2 mg per kg of body weight of cocaine.

None of the volunteers had ever used cocaine before.

Cocaine slightly increased heart rate and blood pressure.

However, it also led to a significant increase in chemicals that indicate that the blood is "stickier" and which enhance the formation of clots.

In addition, the bleeding time - a measure of how long it takes the blood to form a clot around a wound - fell in two-thirds of the volunteers.

The researchers say their data is yet more evidence to disprove the theory that occasional cocaine use poses little risk.

"The risk of thrombosis, similar to the risk of sudden cardiac death, is real and may affect even the first time user of small quantities of the drug."

The ecstasy study is published in the Journal of Neurology, Neurosurgery and Psychiatry, the cocaine study in Heart.