A gene therapy could potentially treat severe alcohol use disorder, according to a new study in non-human primates appearing in Nature Medicine. In the treatment, an adeno-associated viral vector carrying the gene encoding glial-derived neurotrophic factor, or GDNF, is implanted in the brain — repeated ethanol use affects dopaminergic signaling, leading to a decrease in dopamine release — and this appears to reset the dopamine reward pathway. In their study, researchers from Oregon Health & Science University and elsewhere treated four rhesus macaque monkeys that were a model of alcohol use disorder with this therapy to find that their ethanol consumption dropped by 90 percent. "The monkeys that were treated with this gene permanently started overexpressing dopamine and they decreased their drinking substantially," co-senior author Kathleen Grant from OHSU says in a statement. She and her colleagues note that as the treatment involves surgery and permanently alters the brain, it would only be appropriate to use it to treat severe cases of alcohol use disorder.