Diagnosis and treatment of mood disorders that co-occur with schizophrenia

Affective syndromes, particularly mania and depression, often occur during the course of illness in patients who have a diagnosis of schizophrenia. Our current diagnostic system allows clear classification of the overlap of affective symptoms and psychotic symptoms. However, this diagnostic system will eventually require major revisions so that it will more accurately reflect the biologic mechanisms that underlie different symptoms. This article reviews the historical underpinnings of the diagnostic classification of affective and psychotic symptoms, including a discussion of current diagnostic practices and a review of the few studies on treatment of affective symptoms and syndromes in patients with schizophrenia. There is a great need for additional research on treatment of mood disorders that arise during the course of schizophrenia, especially with regard to newer mood stabilizers and antidepressants.