This proposal was designed to examine the effects of gender and menstrual cycle phase on oral and smoked drug self-administration in rhesus monkeys. A goal of the proposed experiments is to extend findings indicating gender and hormonal influences on drug abuse from rodent studies to nonhuman primates using experimental conditions similar to those that elucidate effects of these factors in rodents. Progressive ratio (PR) schedules and a behavioral economic analysis of demand will be used to evaluate the effects of gender and menstrual cycle phase on oral phencyclidine (PCP) and cocaine self-administration. The effects of gender on the escalation of cocaine intake will be examined using a differential access procedure that allows animals short- (1-hr) or long- (6-hr) access to drug self-administration. Following the differential access procedure, gender and menstrual phase differences in the reinforcing effectiveness of cocaine will be assessed using a PR schedule. A PR schedule and demand curve analysis will also be used to determine the relative reinforcing effectiveness of smoked cocaine and methamphetamine in males vs. females and during specific phases of the menstrual cycle.