Cross-sectional survey studies have shown very high rates of coprevalence of eating disorders and substance abuse in young women dieters. Animal studies have suggested that increased drug intake may be caused by food deprivation. Because the onset of clinically significant eating disorders usually antedates the onset of clinically significant substance abuse in patient populations with both disorders, we hypothesize that caloric restriction among young women dieters leads to increased development of substance abuse problems. A preliminary, longitudinal study conducted at the University of Michigan has documented the prevalence of dieting and bulimic behaviors in freshman women as well as the number of incident cases of bulimia nervosa occurring during the freshman year. A preliminary study by the PI shows further that women with a history of bulimic behaviors, but without meeting DSM III R criteria for bulimia nervosa, use substances in a more pathological manner than do subjects without bulimic behaviors. However, no data exist on the role that dieting and bulimic behaviors play in the development of substance use in young women. Such an investigation of the etiology of this clinical phenomenon of comorbidity would require the prospective assessment of dieting severity, bulimic behaviors, and substance use during a period of maximum risk (i.e. the college years). We propose to carry out a longitudinal, three-wave survey study of dieting behaviors and substance use in a large cohort of college women. The results of this study should better define the relationships between dieting behaviors, subclinical bulimic behaviors, the clinical syndrome of bulimia nervosa and drug and alcohol use. The validity and clinical significance of the survey results will be, in part, determined by a parallel, smaller study of severe dieters and nondieters using structured interviews. The data will allow us to: (1) use assessments of dieting and eating behavior to identify women at high risk for future substance abuse; (2) design substance abuse prevention programs targeted at young women who diet severely; and (3) include interventions designed to decrease dieting in the treatment of female substance abusers.