Background: Gender may have a significant impact on the prevalence, age at onset, symptoms, course and outcome of schizophrenia, as well as on the pattern of psychopathology in relatives.
Method: We examined these questions in the Roscommon Family Study, in which the probands were epidemiologically sampled from a case registry and followed up an average of 15 years after onset. Face-to-face interviews were conducted with 86% of traceable living relatives.
Results: The treated lifetime prevalence of DSM-III-R schizophrenia was 0.54 +/- 0.06% in men and 0.28 +/- 0.04% in women. No significant differences were seen in the age at onset, symptoms, course or outcome of schizophrenia. The risks for schizophrenia, schizophrenia spectrum disorders, affective illness and alcoholism were similar in relatives of male and female schizophrenic probands.
Conclusions: Gender has little impact on the presentation and course of schizophrenia in the west of Ireland. The familial liability to schizophrenia did not differ in affected men and women. No evidence was found that schizophrenia in women, compared to men, is, from a symptomatic or familial perspective, more closely related to affective illness. The substantial gender difference in the prevalence rate of schizophrenia in Ireland cannot be explained by women having a greater resistance to the familial predisposition to illness.