Long-term course of schizophrenic illness: Bleuler's study reconsidered.

Objective: The influential 1972 study by Manfred Bleuler on the long-term course of schizophrenic illness has been reconsidered. The authors tested the diagnosis of schizophrenia in all patients and investigated how the distribution of the types of illness course and outcome would change after exclusion of patients whose diagnosis of schizophrenia could not be confirmed by modern diagnostic standards.

Method: Clinical charts and Bleuler's research notes on the original sample were assessed, and all patients were rediagnosed with the help of DSM-IV, DSM-III-R, ICD-10, the Research Diagnostic Criteria (RDC), Schneider's criteria, and an operationalized version of the criteria of Eugen Bleuler.