Scientists find source of craving for drink - and it's all in the mind

Scientists have discovered in the brain a natural chemical involved in alcohol addiction which could become the basis of new drugs to help alcoholics kick their habit.

Scientists have discovered in the brain a natural chemical involved in alcohol addiction which could become the basis of new drugs to help alcoholics kick their habit.

Researchers at the University of California, San Francisco, found that laboratory mice lacking the chemical, an enzyme, showed 75 per cent less interest in drinking alcohol than ordinary mice, which, like humans, can become habitually dependent on drink.

Alcohol is second only to smoking as the biggest cause of avoidable health problems in Britain, with an estimated one in 25 people addicted to it - twice as many as those dependent on other drugs.

Drunk drivers kill 11 people a week, up to 14 million working days a year are lost because of drink and the NHS spends an estimated £150m a year on drink-related health problems. Scientists argue that with more children taking up drinking at an earlier age, new ways of tackling alcoholism are needed.

Clyde Hodge, assistant professor of neurology at the university, said the study on mice indicated that an increased susceptibility to the effects of alcohol actually decreased the cravings for drink.

"These mice support the concept emerging in alcohol research that increased sensitivity to alcohol intoxication lessens the likelihood that a person will become an alcoholic," Professor Hodge said.

The research, published today in the journal Nature Neuroscience, showed that a brain enzyme called protein kinase C-epsilon (PKCe) is a key player in the biochemical pathways that determine sensitivity to alcohol. Mice genetically engineered to lack the PKCe enzyme were far less interested in drinking alcohol than ordinary mice but became intoxicated more quickly.

The researchers believe that in the absence of PKCe, alcohol and drugs such as the benzodiazepine tranquillisers enhance the effect of a substance in the brain known as GABA-A, which controls the signals telling the brain to feel gratified, relaxed or sedated. Drugs designed to inhibit the effects of PKCe in the human brain could offer a new way of dealing with alcoholism that does not involve sedating the patient.

Commenting on the research, Professor Steven Rose, a brain researcher at the Open University, said he would be cautious about relying on drugs to rid society of alcoholism. "Alcohol dependency reflects the impoverishment of society. We're not going to deal with the effects of alcohol on society by saying, 'Pop this pill and you'll be cured'," he said.