The rising epidemic of pediatric obesity has become a national health care priority due to the cumulative medical and psychosocial consequences across the lifespan. The degree of obesity has also increased at an alarming rate making the severely obese adolescent (BMI >= 40 kg/m2}) a population for which there is notable concern. Given the paucity of effective treatment for adolescent obesity, and severe obesity in particular, surgical interventions are now being explored. Bariatric surgery in adults results in impressive weight loss and the improvement, if not resolution, of most obesity-related comorbidities, including improved mood and quality of life. Given that comprehensive study of adolescents seeking bariatric surgery has not previously been conducted there is a substantial gap in our understanding of the psychosocial comorbidities of this unique population and the predictors of positive short- and long-term surgical outcomes. Our long-term goals are to significantly improve the health and quality of life of youth who are obese through the identification of predictors of successful pediatric weight management. The primary objective of this application, which represents an important next step toward attainment of this long-term goal, is to generate pilot data to determine the psychosocial benefits of bariatric surgery in the treatment of severely obese adolescents as well as identify psychosocial predictors of successful surgical outcomes. These pilot data will establish feasibility of the proposed research design for a multi-site R01 submission. The present pilot study will assess four domains of psychosocial functioning in obese adolescents (ages 13-17) who meet criteria for severe obesity (BMI>40 kg/m}) and are referred for bariatric surgery. These four domains include psychological adjustment, binge eating, quality of life, and interpersonal relationships. Controls will be severely obese adolescents who have sought behavioral weight management treatment. Participants will complete the assessment measures prior to and at 6- and 12-months post-initiation of treatment. Identifying psychosocial correlates of severe obesity in adolescence associated with successful surgical outcomes and long-term maintenance of weight loss will be critical to the development of more informed patient selection criteria and more efficacious treatment paradigms.