This project aims to study the whole-body metabolic processes responsible for hyperglycemia, dyslipidemia and increased adiposity in schizophrenia patients treated with antipsychotic medications in combination with valproate. The project hypothesizes that combined treatment with valproate and antipsychotic medications will decrease insulin sensitivity at the level of skeletal muscle, liver and adipose tissue, in comparison to antipsychotic monotherapy. The decrease in insulin sensitivity is hypothesized to be associated with defects in glucose and lipid metabolism and increased adiposity