A form of therapy used to treat Parkinson’s disease may be able to help dramatically reduce alcohol use among chronic heavy drinkers, research suggests.
The study in macaque monkeys found that implanting a specific type of molecule in the brain may prevent a return to excessive alcohol use after a period of abstinence.
The gene therapy procedure involves brain surgery, and researchers say this could be useful in the most severe cases of alcohol use disorder.
In the study, a non-harmful virus was injected in a specific area of the brain of a group of rhesus macaque monkeys that voluntarily and heavily drink ethanol diluted in water.
After four macaques underwent the procedure, researchers found their consumption dropped by more than 90 per cent compared with those who did not.
Co-principal investigator Krystof Bankiewicz, professor of neurological surgery at Ohio State College of Medicine in the US, said the gene therapy targets changes in dopamine function in the brain’s reward pathway caused by chronic alcohol use.
“Our findings suggest that this treatment can prevent relapse without requiring long-term treatment adherence by patients,” he said.
Co-senior author Kathleen Grant, chief of neuroscience at the Oregon National Primate Research Centre, said drinking in the macaques involved in the study went down to almost zero.
“For months on end, these animals would choose to drink water and just avoid drinking alcohol altogether.
“They decreased their drinking to the point that it was so low we didn’t record a blood-alcohol level.”
In the case of alcohol use disorder – a problematic pattern of alcohol use leading to significant impairment or distress – chronic drinking decreases the release of dopamine – a feel-good chemical released in the brain.
Prof Grant said acute alcohol use can increase dopamine but by drinking it chronically, the brain adapts in such a way that it decreases the release of dopamine.
“So when people are addicted to alcohol, they don’t really feel more pleasure in drinking.
“It seems that they’re drinking more because they feel a need to maintain an intoxicated state.”
The procedure used in the study is already used in adult patients with Parkinson’s disease.
Because the new study, published in Nature Medicine, describes a form of treatment that permanently alters the brain through surgery, it would be limited to those with the most severe forms of alcohol use disorder.
Nina Massey
(Australian Associated Press)
