 BN is a serious disorder that is characterized by extreme concerns about body weight and shape, dieting, and the disinhibited eating behaviors of binging and purging. There are no published randomized clinical trials of psychotherapy treatment for Bulimia Nervosa in adolescents although it often onsets in this age group. There is evidence that some treatments are effective, but none has been empirically tested. Because Bulimia Nervosa is a serious medical and psychiatric illness it is important to learn efficacious ways to treat this disorder, especially in its early stages. Treatments used in this study are the best known treatments for adults with Bulimia Nervosa. The investigators hope to learn which of two previously studied treatments might be superior to the other, in an effort to guide clinicians in treatment choices. Successfully treating the disorder early on even in those adolescents with partial BN, characterized by binge eating and purging at least one time per week over a 6 month period may reduce the number of cases requiring treatment during adulthood, leading to possible reduction in severity of associated psychopathology and lower costs, as well as enable individuals to lead more productive lives. 