Men are significantly more likely than women to suffer from alcoholism and to seek substance abuse treatment for their problems. However, until recently, health experts were unable to explain this difference.

Recent research by investigators from Yale and Columbia University has revealed that the answer to this problem may have to do with differences in dopamine levels.

Researchers had study participants drink an alcoholic beverage, then measured their brain activity. They found that men had higher levels of dopamine in their brains after drinking than women. Dopamine is a neurotransmitter that is associated with responses to pleasurable stimuli. It has been linked to addiction to other drugs, such as cocaine and opioids.

"In men, increased dopamine release also had a stronger association with subjective positive effects of alcohol intoxication," explained Nina Urban, who led the investigation. "This may contribute to the initial reinforcing properties of alcohol and the risk for habit formation."

She added that drinkers build up a tolerance to the effects of alcohol over time, and that it takes more of the beverage to create the same dopamine response. Drinking more alcohol may increase the risk of addiction.