This project aims to a) evaluate the effects of haloperidol, olanzapine, and risperidone in combination with valproate on insulin secretion and insulin actions, b) evaluate medication effects on abdominal fat, total body fat and total fat-free mass, and c) evaluate treatment effects on glucose tolerance, lipid profiles, and plasma levels of leptin, adiponectin, ghrelin and C-reactive protein. Hypotheses will be evaluated by measuring 1) insulin action and secretion using frequently sampled intravenous glucose tolerance tests, 2) body composition using dual energy x-ray absorptiometry, magnetic resonance scans, and anthropomorphic measurements, and 3) changes in hormone levels and lipid profiles. The aims will be addressed in non-diabetic schizophrenia patients chronically treated with haloperidol, olanzapine or risperidone who will have valproate added to their treatment. Relevant data is critically needed to target basic research, identify long-term cardiovascular risks, and plan therapeutic interventions.