The discovery of a system in the brain that can stop cravings for alcohol may open the door to new treatment techniques for alcoholics, said Australian researchers

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SYDNEY: A system in the brain that stops an alcoholic's craving and prevents a relapse to alcohol has been discovered by Australian researchers.

The 'orexin' system is a group of cells in a part of the brain called the hypothalamus. These cells produce orexin, a neuro-chemical that was originally implicated in the regulation of feeding. According to the research team, though, orexin is also involved in the 'high' felt after drinking alcohol or taking illicit drugs.

In studies conducted with rats, Andrew Lawrence and colleagues at the Howard Florey Institute in Melbourne tested a drug that blocked orexin's euphoric effects in the brain, with remarkable results. "In one experiment, rats that had alcohol freely available to them stopped drinking it after receiving the orexin blocker," said Lawrence.

"In another experiment, rats that had gone through a 'detox' program and were then given the orexin-blocking drug did not relapse into alcohol addiction when they were reintroduced to an environment in which they had been conditioned to associate with alcohol use.

"Orexin reinforces the euphoria felt when drinking alcohol, so if a drug can be developed to block the orexin system in humans, we should be able to stop an alcoholic's craving for alcohol, as well as preventing relapse once the alcoholic has recovered," he said.

According to Lawrence, this research, which appeared recently in the British Journal of Pharmacology, could also lead to treatments for eating disorders, such chronic over-eating. "Our research shows that alcohol addiction and eating disorders set off common triggers in the brain, so further investigations may uncover drug targets in the orexin system to treat both conditions."

The team is now conducting multiple experiments to discover the precise circumstances that activate the orexin system.

"To explore this discovery further we are now investigating how different experimental paradigms and environmental situations impact on the orexin system, which will hopefully pinpoint therapeutic drug targets," Lawrence said. "Before a therapeutic orexin-blocking drug can be developed, we need to ensure that it will be safe to use in the long-term and that issues surrounding a person's compliance in taking the drug are considered."

According to the World Health Organisation, alcohol is one of the most widely used and abused substances in the world and causes as much - if not more - death and disability as do measles, malaria, tobacco, or illegal drugs.

Lawrence and his colleagues were the first in the world to demonstrate the orexin system's involvement in alcohol addiction.