Outcome and family study of the subtypes of schizophrenia in the west of Ireland.

Abstract

The authors sought to clarify differences in outcome and familial psychopathology among the classical subtypes of schizophrenia. In the epidemiologically based Roscommon Family Study, personal interviews were conducted with 88% of traceable living probands (N = 415) an average of 16 years after illness onset and with 86% of traceable living first-degree relatives (N = 1,753). Probands meeting the DSM-III-R criteria for schizophrenia were subtyped by DSM-III-R and ICD-9. By both diagnostic systems, age at onset differed significantly across subtypes, being earliest in the subjects with the hebephrenic and catatonic subtypes and latest in the paranoid subjects. The probands with the paranoid subtype had substantially better outcome, especially in occupational functioning and capacity for self-care. The DSM-III-R criteria for paranoid schizophrenia were considerably more successful than the ICD-9 criteria in selecting good-outcome cases. Neither the risk for schizophrenia nor the risk for schizophrenia spectrum disorders significantly differed in relatives as a function of the proband subtype. The subtypes of schizophrenia did not "breed true" within families. Paranoid schizophrenia, especially when narrowly defined, as in DSM-III-R, has a substantially better outcome than other subtypes. From a familial perspective, 1) paranoid schizophrenia is not a milder form of schizophrenia and 2) catatonic schizophrenia is probably closely related to typical schizophrenia. The subtypes of schizophrenia are not, from a familial perspective, etiologically distinct syndromes.