Outcome of Schizophrenic Subtypes Defined by Four Diagnostic Systems

• This report examines the short- and long-term outcome of the subtypes of schizophrenia as defined by four diagnostic systems: DSM-III, Research Diagnostic Criteria, Ninth Revision of the International Classification of Diseases, and the Tsuang-Winokur (T-W) criteria. Patients were from the Iowa 500 study and met Washington University criteria for schizophrenia. Subtype diagnosis was based on extensive chart material reviewed by investigators blind to outcome. Short-term outcome, based on chart information, and long-term outcome, based on individual field follow-up, were both better for paranoid than for nonparanoid schizophrenia, the difference being greatest using the T-W criteria. The difference in outcome between paranoid and nonparanoid schizophrenia was greater at long-term than at short-term follow-up, and greater using residential and occupational than psychiatric outcome criteria. Outcome did not differ for the two common forms of nonparanoid schizophrenia: hebephrenic and undifferentiated. The subtyping of schizophrenia has important predictive validity, which was greatest using the T-W criteria.