THE NETHERLANDS:Researchers have identified a gene variation that seems to influence a person's craving for alcohol, a finding they believe could have implications for identifying at-risk drinkers, as well as for selecting the best treatment for a patient's dependence.
The gene mutation involves a cell structure called the mu-opioid receptor. In previous studies, this receptor has been shown to bind beta-endorphin, a pain-relieving chemical which the body releases in response to alcohol intake and other stimuli.
Further research has shown that when the gene variant, or the G allele, is present, the receptor binds to beta-endorphin more strongly than when the more common A allele is present.
Dr Esther van den Wildenber of the University of Maastricht in The Netherlands, and colleagues investigated the impact of the A and G alleles on alcohol craving.
The study, reported in the journal Alcoholism: Clinical and Experimental Research, included 84 men who carried only the A allele and 24 who carried at least one copy of the G allele. Family histories of alcoholism were comparable in each group.
Craving, arousal and salivation were assessed for each subject after exposure to water or beer in three-minute trials, the report indicates.
G allele carriers showed significantly more craving than did subjects with only the A allele. Arousal and salivation, by contrast, did not differ significantly between the groups. The authors found that G allele carriers were more likely to also report illicit drug use at some point in their lives.
"Studies like this one are important in terms of saying something about how a gene might be involved in alcohol dependence," Dr Kent Hutchison, an associate professor from the University of Colorado at Boulder who was not involved in the study, said in a statement.
"At this point in time, this gene definitely seems to be one of the key genes related to alcohol dependence," he said. "There will undoubtedly be others."