Classical subtypes for schizophrenia: literature review for DSM-IV.

The classical subtypes of schizophrenia include the paranoid, hebephrenic, undifferentiated, residual, catatonic, and simple. This review of studies, especially those conducted during the last decade, supports the validity of the subtypes, particularly the paranoid subtype. To a lesser degree, the same holds for the hebephrenic and undifferentiated subtypes. The catatonic subtype has seldom been studied, perhaps because it is so rare. The residual and simple subtypes have not been the focus of any studies of note. Subtype criteria for DSM-IV are suggested based on the review. The paranoid and undifferentiated subtypes should be retained with criteria identical to those in DSM-III-R. The disorganized subtype also should be retained but with modified criteria that are somewhat more stringent than those in DSM-III-R. Catatonia and residual schizophrenia should remain, but insufficient data exist upon which to base any changes in criteria. Given its historical precedence, as well as the emerging importance of deficit processes in schizophrenia, simple schizophrenia should be renamed and reintroduced as a subtype in DSM-IV. Two variations in criteria are offered.