Directions for future research.

Key questions for future research into metabolic concerns in mentally ill patients are: (1) Which mechanisms contribute to an elevated risk of diabetes in patients with psychotic and mood disorders? and (2) Which risk factors or susceptibility mechanisms are at work in the minority of patients who experience diabetes when treated with atypical antipsychotics? The authors suggest the need for large, randomized, prospective, longitudinal trials comparing the effects of different atypical antipsychotics on fasting glucose; metabolic studies of patients before and during randomized treatment with atypical antipsychotics; and studies to better characterize neurobiologic abnormalities associated with acute and chronic psychotic and mood disorders.