Tuesday, December 6, 2011

Ecstasy can produce chronic long-lasting changes to the human brain, say scientists


Illegal high: Scientists say Ecstasy tablets (pictured) can cause 
long-lasting damage

The illegal drug could cause lasting damage to brain's serotonin levels
Illegal high: Scientists say Ecstasy tablets (pictured) can cause long-lasting damage
Recreational use of Ecstasy is associated with chronic long-lasting changes in the human brain, Vanderbilt University investigators in Tennessee have discovered.

The findings, reported in the Archives of General Psychiatry, add to the growing evidence that the illegal ‘rave’ drug produces long-lasting damage to the brain’s serotonin levels, said associate professor of Psychiatry Ronald Cowan.

‘Our study provides some of the strongest evidence to date that the drug causes chronic loss of serotonin in humans’, he said of the chemical that produces feelings of euphoria.

The neurotransmitter serotonin, a critical signaling molecule, has roles in regulating mood, appetite, sleep, learning and memory.

The current study is important, Cowan said, because MDMA (Ecstasy's chemical name) may have therapeutic benefits and is now being tested as a treatment for post-traumatic stress disorder and anxiety associated with cancer.

‘It's essential that we understand the risk associated with using Ecstasy,’ Cowan said. 
 
‘If news keeps coming out that MDMA is being tested therapeutically and is safe, more people will tend to self-administer the drug. We need to know the dose at which this drug becomes toxic.

‘Our studies suggest that if you use Ecstasy recreationally, the more you use, the more brain changes you get.’

In the current study, Cowan and colleagues used positron emission tomography (PET) imaging to examine the levels of serotonin-2A receptors in various brain regions, in women who had used Ecstasy (but not in the 90 days prior to imaging) and in women who had never used the drug.
Rave drug: Ecstasy is known as an illegal 'rave' drug that creates
 feelings of euphoria (library image of ravers)
Rave drug: Ecstasy is known as an illegal 'rave' drug that creates feelings of euphoria (library image of ravers)
They limited their studies to women because previous work has shown gender-specific differences in serotonin receptor levels.

They found that Ecstasy users had increased levels of serotonin-2A receptors and that higher lifetime use of the drug (higher doses) correlated with higher serotonin receptor levels.

The findings are consistent with some studies in animal models, with receptor levels increasing to compensate for the loss of serotonin, Cowan said.

Cowan and colleagues reported earlier this year that Ecstasy increased brain activation in three brain areas associated with visual processing, which suggested a loss in brain efficiency.

Together, the two studies provide compelling evidence that Ecstasy causes lasting changes in brain serotonin function, Cowan said.

‘It's really critical to know whether or not this drug is causing long-term brain damage because millions of people are using it,’ he said.

The 2010 National Survey on Drug Use and Health estimated that 15.9 million individuals 12 years or older in the United States had used Ecstasy in their lifetime; 695,000 people had used Ecstasy in the month prior to being surveyed.

Cowan is interested in determining the doses of Ecstasy that are toxic, and whether there are genetic vulnerabilities to toxicity.

If clinical trials show that the drug has therapeutic benefits, it's critical to know the risks, he said.

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