Researchers have discovered a gene that regulates alcohol consumption and when faulty can cause excessive drinking. They have also identified the mechanism underlying this phenomenon. The study showed that normal mice show no interest in alcohol and drink little or no alcohol when offered a free choice between a bottle of water and a bottle of diluted alcohol. However, mice with a genetic mutation to the gene Gabrb1 overwhelmingly preferred drinking alcohol over water, choosing to consume almost 85% of their daily fluid as drinks containing alcohol -- about the strength of wine.