- Main Study: Subjects cannot have a current or past DSM-IV diagnosis of alcohol or drug dependence, current or past 24-months diagnosis of alcohol or drug abuse or another major psychiatric disorder, neurological illness, have had a hypersensitivity reaction to dutasteride, evidence of liver dysfunction, currently be using benzodiazepines, other psychotropic medications or medications that are known to influence steroid hormone levels or metabolism or modify the effects of alcohol. Nicotine-dependent subjects will be excluded to avoid the confounding effects of nicotine withdrawal during day-long laboratory sessions. Women are not allowed to participate. Subjects anticipating moving from the area during the period of their planned study participation will be excluded from study entry.