Treatment effects of antipsychotic/valproate combination therapy on different components of insulin secretion and action, and treatment effects on abdominal versus peripheral adiposity, are unknown despite the availability of gold-standard methods and the prognostic significance of these issues. Relevant data are needed to target basic research, to identify the potential for acute and long-term complications, and to plan therapeutic interventions. The following specific aims will be addressed in non-diabetic schizophrenia patients treated with atypical antipsychotics who will be randomized to open label treatment with either valproate or no adjuvant. Evaluations are performed at baseline and 3 months of treatment.