Studies show that men are twice as likely to develop alcoholism than women; however, the underlying biological factors contributing to this difference has been, for the most part, unclear. A new study published in Biological Psychiatry, points to dopamine being an important factor in this difference.
Dopamine is a key neurotransmitter in the reward center of the brain that plays an important role in our ability to handle stress, be motivated, and create an overall sense of well-being. The use of drugs or alcohol raises the level of dopamine and confuses the brain into thinking that the action was positive and should be repeated.
Researchers from Columbia and Yale University studied alcohol consumption amongst male and female social drinkers. After consuming alcoholic or non-alcoholic drinks, each participant underwent a PET scan that measured the amount of alcohol-induced dopamine released.
Despite similar consumption of alcohol, the study found men to have greater amounts of dopamine released than the women. The increase was found in an area of the brain (ventral striatum) strongly associated with pleasure, reinforcement and addiction. Because of the increased release of dopamine, men had a stronger positive association with the effects of alcohol intoxication. This initial positive reinforcement may contribute to the risk for habit formation.
The study also found that episodes of repeated heavy drinking resulted in a decline in alcohol-induced dopamine release. This observation supports one of the hallmarks of developing tolerance or transitioning into a more chronic dependence on alcohol.
