 - Subjects will be excluded with a diagnosis of any other substance dependence syndrome other than alcohol dependence, nicotine dependence, andor caffeine dependence. However, individuals may have a history of episodic abuse of cannabis, cocaine, sedativeshypnotics and opiates, amphetamines, and hallucinogens. Also, subjects may be on prescription benzodiazepine or related sedativehypnotic therapy. 