The incidence of type 2 diabetes mellitus (DM2) in youth is increasing dramatically with the rise in obesity in the U.S. and worldwide. DM2 in youth, as with adults, is clearly linked to modifiable risk factors such as obesity, sedentary lifestyle, and poor diet. Youth with DM2 are at increased risk for medical complications such as cardiovascular disease, retinopathy, and neuropathy, as well as psychological problems such as depression, anxiety, poor self-esteem, eating disorders, and poor coping and problem solving. Although there are studies demonstrating that family-based lifestyle and psychological interventions are successful in reducing obesity in youth and in improving metabolic control and adherence in youth with type 1 diabetes mellitus (DM1), very little has been published on potential lifestyle or psychological treatments for youth with DM2. Studies have shown that Behavioral Family Systems Therapy (BFST) has been effective in improving metabolic control, adherence, family communication, and problem solving in youth with DM1. This intervention could be effective in treating youth with DM2, as many of the skills necessary for good metabolic control, health outcomes, treatment adherence, and psychological adjustment are similar in both populations. This application proposes a randomized, controlled pilot trial of BFST-DM2, an individual psychological intervention tailored to meet the needs of teens with DM2. BFST will be adapted to make this intervention more feasible and relevant with minority and low-income populations and also to focus on weight management, exercise, and nutrition. The BFST-DM2 intervention includes 12 (90-minute) sessions over 6 months. Areas targeted for improvement will include metabolic control, weight/body mass index, treatment adherence, family lifestyle choices (activity, diet), family communication, and problem solving. One of the main aims of this pilot study is to gather exploratory information on the effectiveness of the BFST-DM2 intervention on measures of health outcomes, medical adherence, lifestyle changes, and family problem-solving and communication skills. In addition, it is an aim to estimate treatment effect size to determine the sample size needed to power a larger multi-site trial of the BFST-DM2 intervention. Other aims include determining factors associated with feasibility (recruitment, retention, participation, generalizability) as well as to modify the intervention to be culturally sensitive and to be more relevant to the individual needs of the DM2 adolescent population. The BFST-DM2 intervention will be compared with standard medical therapy on measures of health outcomes (metabolic control, body mass index, weight, waist circumference, body fat) physical activity (accelerometer), nutritional intake, treatment adherence, psychological adjustment (self-esteem, quality of life), family communication, and problem solving. The researchers will analyze predictors of treatment outcome and the treatment effects at the immediate post-treatment interval (6 months from baseline). Health outcomes and medical adherence data also will be collected 12 months from baseline to determine maintenance of treatment effects over time.