- Main Study: Subjects will be healthy volunteers with or without parental history of alcoholism who are 21-45 years old and who have a BMI >18.5 and <32.5. Drinking history: All subjects must report at least one occasion in the prior month of drinking at least 3 drinks on a single day; additionally, LD subjects will be selected if they drink 1-3 drinks, 1-3 times per week (up to 5 drinks per week on average), with no more than one occasion in the past 2 months on which they drank >4 drinks. HD subjects will be selected if they report drinking at least 10 drinks per week, with at least one episode per week of heavy drinking.