Bulimia is characterized by recurrent episodes of binge eating and severe self-deprecation, often accompanied by self-induced vomiting and/or laxative abuse. It is most often found among young women in their late teens to mid-30s. Estimates of the disorder's prevalence vary widely, depending on the diagnostic criteria used, but usually range from 5% to 20% of college age women. Binge eating typically begins in late adolescence, frequently after a period of dieting to lose weight. Self-induced vomiting usually follows the onset of binge eating by about a year. To date, theories of the disorder's etiology have included several biological models, a psychosocial model, and a biopsychosocial model. The biological models proposed have viewed bulimia as a form of biological depression, neurological disturbance, or metabolic disturbance. The psychosocial model suggests that society's pressure on young women for extreme thinness leads to excessive dietary restraint, deprivation, and, paradoxically, binge eating. The presence of anxiety or depression exacerbates the process. The biopsychosocial model appears to be the most promising. It proposes that young women with biological predispositions toward overweight, depression, or metabolic disturbance are particularly vulnerable to social pressure for thinness, the binge eating that may result from excessive dieting, and, hence, bulimia. The complex nature of bulimia suggests that a multidisciplinary team approach treatment is appropriate.