The specific aims of the proposed research are to characterize neuropsychological deficits caused by chronic anabolic steroid exposure. Using the rat as an animal model, the following hypothesis will be tested: Chronic use of anabolic steroids produces cognitive deficits on tasks involving visuospatial memory. Our specific aims are: First, to characterize the learning and memory deficits produced by prolonged use of anabolic steroids. Second, to examine in detail whether the age at time of exposure is a critical factor in determining the extent of cognitive impairment. Specifically, does adolescent exposure to anabolic steroids produce greater deficits in learning and memory than exposure in adulthood? Third, to examine whether the cognitive impairments associated with chronic anabolic steroid exposure are permanent or whether they dissipate after a prolonged period of drug abstinence. Fourth, to determine whether there is a dose-response relationship between the effects of anabolic steroids and spatial learning. These studies will establish the relative potency of a range of anabolic steroids on learning and furthermore, will indicate whether there is a threshold dose of anabolic steroids required to produce learning deficits or whether a continuum exists. The proposed studies could have far reaching clinical significance. Although a great deal of research and anecdotal information exists concerning the motivational factors associated with anabolic steroid misuse, there is virtually no information on the adverse neuropsychological effects of steroid misuse. Considering that the use of anabolic steroids by athletes is widespread and that the incidence of use among adolescent athletes appears to be growing, our studies could help identify critical, heretofore unrecognized, damaging effects of anabolic steroids on learning ability and the brain.