London, Oct 20 (IANS) Men are twice as likely as women to become alcoholics and now scientists believe they know why. They found that consuming beer and wine on a night out gave men a far greater 'pleasure rush' than women.

Researchers from Columbia and Yale universities in the US studied the underlying biology of how drinking affects the brain. The team compared a group of male and female college-age social drinkers in a lab test of alcohol consumption, reports the Daily Mail.

After consuming an alcoholic or non-alcoholic drink, each participant underwent a specialised positron emission tomography (PET) scan, an imaging technique that can measure the amount of alcohol-induced dopamine release.

Dopamine has 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, according to the journal Biological Psychiatry.

This increase was found in the ventral striatum, a brain area strongly linked with pleasure, reinforcement and addiction formation.

Study co-author Nina Urban from Columbia University said: "In men, increased dopamine release also had a stronger association with subjective positive effects of alcohol intoxication."

"This may contribute to the initial reinforcing properties of alcohol and the risk for habit formation."