The purpose of this research study is to learn whether oxytocin treatment decreases drinking and alcohol craving in people who have been consuming alcohol heavily for long periods and are unable to stop drinking on their own. Oxytocin is made naturally and is released in parts of the brain where it acts like a chemical signal from one cell to another. Oxytocin is approved by the Food and Drug Administration for stimulating labor in pregnant women but is not approved as a treatment to decrease alcohol drinking.