Objective: Gender appears to have a significant impact on the prevalence, age at onset, symptoms and outcome of schizophrenia. This study examines gender effects in a population of familial schizophrenic patients in Ireland.
Method: Families with two or more siblings suffering from schizophrenia, as defined by DSM-III-R were ascertained in Ireland. The final sample comprised 169 siblings from 80 families. Siblings were interviewed using the Structured Clinical Interview for DSM-III-R (SCID), the Scale for the Assessment of Negative Symptoms (SANS) and the Strauss-Carpenter Levels of Functioning Scale. The difference between males and females for various clinical features were calculated.
Result: There was a marked excess of affected males (65% male and 35% female). When the excess of male subjects was taken into account there was no significant excess of same-sex as compared to opposite-sex pairs. There were no significant difference between males and females for age at onset, age at first admission, symptoms or level of outcome.
Conclusion: The excess of males and the lack of gender differences for clinical features found in this study may, in part, be due to the narrow diagnostic criteria used. Alternatively, at least some of these findings may be specific to this Irish sample. Further research is a need to see if these findings can be replicated in other countries.