Pubdate: Tue, 11 Nov 2008
Source: Guardian, The (UK)
Copyright: 2008 Guardian Newspapers Limited
Contact:  http://www.guardian.co.uk/guardian/
Details: http://www.mapinc.org/media/175
Author: Ian Sample, science correspondent
Bookmark: http://www.mapinc.org/coke.htm (Cocaine)

ALL IN THE FAMILY - SCIENTISTS DISCOVER GENE FOR COCAINE ADDICTION

It has become commonplace for people who are overweight to attribute 
their waistline to their DNA. Now, celebrities caught snorting 
cocaine might also be able to blame their parents.

Scientists reported yesterday the discovery of a gene that increases 
the chances of becoming hooked on the drug. Addicts were 25% more 
likely to carry the gene variant than people who did not use cocaine, 
a study found.

The discovery is unlikely to lead to a treatment for cocaine addicts, 
but scientists hope it could be used to screen for those most likely 
to have problems kicking the habit if they ever try the drug.

"If you are a carrier of this gene variant, the likelihood of getting 
addicted to cocaine is higher," said Rainer Spanagel, a professor of 
psychopharmacology at the Central Institute of Mental Health in 
Mannheim, Germany, who led the study. "You can certainly use this as 
a vulnerability marker for cocaine addiction."

He said people found to be susceptible to cocaine addiction could be 
given counselling or protected with experimental vaccines now being 
developed. The vaccines are designed to block the "high", or 
euphoria, associated with the drug.

Last week, an analysis by the European Union's drug agency put 
Britain at the top of its list of cocaine-abusing states, with its 
users outnumbering all those elsewhere on the continent.

Genetic factors, scientists believe, account for 70% of cocaine 
addiction, making it as heritable as schizophrenia and other mental 
health conditions. Studies of twins suggest alcoholism is about 50% genetic.

Researchers linked a version of the CAMK4 gene with cocaine addiction 
after studying mice that had been genetically modified to alter the 
gene. One particular breed was affected more strongly by the drug and 
became addicted quicker than others in the group, according to the 
study in the US journal, Proceedings of the National Academy of Sciences.

To see if the gene played a role in cocaine addiction in humans, the 
researchers ran genetic tests on 670 cocaine addicts and more than 
700 matched non-users. While 40% of non-users carried the gene, it 
was found in half of the addicts.
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