Because a substantial minority of individuals with bulimia nervosa do not respond to current treatments, it is critical to develop alternative treatments for this serious disorder. This research has two specific aims. First, to refine and standardize a treatment manual of a functional contextual treatment for bulimia nervosa (FC- BN) for which we have collected some preliminary data. To this end, we will recruit 10 persons with BN or EDNOS that is similar to BN and treat them individually using a tentative outline of FC-BN we have developed in our preliminary work, refining and elaborating this outline as needed, until we have a detailed session-by-session treatment manual. Second, to conduct a small pilot study of FC-BN. To this end, we will test our completed treatment manual with 40 individuals with either BN or EDNOS that is similar to BN. Participants will be randomized to either an immediate treatment condition or a three month delayed treatment condition. The latter group will be crossed over to receive treatment following the waiting period. Three month follow-ups will be conducted on all participants. We hypothesize that FC-BN will result in significant reductions in bulimic symptomatology. We also hypothesize that FC-BN will have high completion rates and low levels of attrition. Bulimia nervosa remains a significant problem among adolescent and young adult females, with high rates of medical and psychiatric comorbidity. While effective treatments for bulimia nervosa exist, a substantial minority of individuals do not respond to them. The proposed study will develop and test the efficacy of a new treatment based on a functional contextual conceptualization of the disorder. ? ? ?