Dec 25, 2006
From BBC news
A team from Melbourne's Howard Florey Institute discovered blocking the action of the brain's orexin system can also prevent someone relapsing.
Team members say their work could lead to the development of drugs which could act as orexin blockers.
Orexin-producing cells are also thought to play a part in regulating feeding, so the researchers believe they could also help treat eating disorders.
Alcohol-related deaths and illness are an increasing problem in the UK.
Deaths rose to 8,386 in 2005 compared to 4,144 in 2001, according to figures from the Office for National Statistics.
And hospital admissions for alcoholic liver disease have more than doubled in a decade, reaching 35,400 in 2004/5.
Orexin cells are in a part of the brain called the hypothalamus.
The chemical is involved in the "high" felt after drinking alcohol or taking illicit drugs.
In rat studies, a team led by Dr Andrew Lawrence created a compound which was seen to block the "euphoric" effects of orexin.
In one experiment, rats that had alcohol freely available to them stopped drinking it after receiving the orexin blocker.
In a second, rats that had gone through a detox programme and were then given the orexin blocking drug did not show any interest in alcohol when they were re-exposed to the kind of environment which they had been conditioned to associate with alcohol use.
Dr Lawrence said: "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 added: "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 scientists are now carrying out further studies to discover exactly how the orexin system is activated.
Dr 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."
Bob Patton, a health psychologist at the UK's National Addiction Centre, said: "The results of this preliminary research are certainly interesting; however more research is required to determine if it works on the complex human brain.
"We already know that [the drugs] Acamprosate and Naltrexone can help reduce cravings and promote abstinence.
"This study offers a further line of investigation that could eventually help the one million alcohol dependant adults in the UK.
"Of course there will be no magic bullet in the treatment of alcohol disorders; pharmacological treatments work in conjunction with psychological therapies to help address the symptoms of dependence.
"And in the future, work on the genetic basis for addiction could help to determine which treatments work best for particular individuals."
See also Physorg.com