Distinguishing bipolar disorder from schizophrenia in clinical practice: guidelines and case reports.

Through the use of more refined diagnostic criteria and biological tests, researchers are finding that affective illness afflicts far more patients and schizophrenia far fewer patients than was formerly believed. The presence of putative "schizophrenic" symptoms is no longer held to be valuable in distinguishing between manic-depressive illness and schizophrenia. The author briefly reviews studies dealing with manic-depressive and schizophrenic symptomatology as well as tentative evidence from treatment-response studies and laboratory studies. Three case reports illustrate the tragedy of misdiagnosis.