1/2-MC4R Genotype and Pediatric Antipsychotic Drug- Induced Weight Gain

We will conduct a 12-week, randomized open label study, comparing usual care (UC) antipsychotic treatment (aripiprazole, quetiapine, risperidone) with ziprasidone (ZIP) in children and adolescents aged 13-18 years old. Patients will have 10 days or less lifetime antipsychotic exposure and be in clinical need for antipsychotic treatment for a pediatric psychiatric disorder with FDA indication for antipsychotic use, i.e., bipolar mania, schizophrenia-spectrum disorders, and irritability associated with autistic disorder. In addition, we will also include youth fulfilling research diagnostic criteria for severe mood dysregulation (SMD). Randomization will be stratified by high vs. low genetic risk for antipsychotic-induced weight gain based on MC4R genotype and the primary outcome will be weight change from baseline to endpoint between ZIP and UC antipsychotic treatment in each of the two genotype groups. As detailed below, other metabolic and cardiac safety parameters will also be measured and compared across treatments in each of the genotype groups.