ScienceDaily (Oct. 18, 2010) — Alcohol is one of the most commonly abused substances, and men are up to twice as likely to develop alcoholism as women. Until now, the underlying biology contributing to this difference in vulnerability has remained unclear.
A new study published in Biological Psychiatry reveals that dopamine may be an important factor.
Researchers from Columbia and Yale studied male and female college-age social drinkers in a laboratory test of alcohol consumption. After consuming an alcoholic or non-alcoholic drink, each participant underwent a specialized positron emission tomography (PET) scan, an imaging technique that can measure the amount of alcohol-induced dopamine release. Dopamine has multiple functions in the brain, but is important in this context because of its pleasurable effects when it is released by rewarding experiences, such as sex or drugs.
Despite similar consumptions of alcohol, the men had greater dopamine release than women. This increase was found in the ventral striatum, an area in the brain strongly associated with pleasure, reinforcement and addiction formation.
“In men, increased dopamine release also had a stronger association with subjective positive effects of alcohol intoxication,” explained Dr. Nina Urban, corresponding author for this study. “This may contribute to the initial reinforcing properties of alcohol and the risk for habit formation.”