Transnational stability of gender differences in schizophrenia? An analysis based on the WHO study on determinants of outcome of severe mental disorders.

Gender-specific analyses of the multinational WHO-Determinants of Outcome-Study (including 1,292 cases from 10 countries) demonstrate the transnational stability of major findings on gender differences in schizophrenia: Male patients have an earlier mean age at onset in all countries. In female patients, the distribution of the age at onset shows a second peak after age 40 years. No gender differences on nuclear symptoms of schizophrenia can be detected, but on uncharacteristic symptoms, particularly some aspects of the illness behaviour, differences appear. This investigation supports the transcultural validity of gender differences found in the German ABC-Schizophrenia-Study and in the Danish-German Psychiatric Case Register studies.