The role of gender in understanding the familial transmission of schizoaffective disorder

Abstract

The purpose of this study was to test the effect of gender on the familial risk for schizophrenia and affective disorders in probands with schizoaffective disorder. The sample consisted of 42 DSM-III schizoaffective probands and 149 first-degree relatives from the retrospective cohort family studies, the Iowa 500 and non-500. Survival analysis estimated differences in morbidity risks, analysed by sex of proband and of relative. Findings showed that, among probands, relatives of females had significantly higher rates of schizophrenia and unipolar disorder than relatives of males. Further, among relatives, males were at significantly higher risk for schizophrenia spectrum disorders than females. Results were similar when probands were subdivided into their primary symptom patterns, that is 'mainly schizophrenic' or 'mainly affective', as well as by 'schizoaffective, depressed' or 'schizoaffective, manic'. Implications for the taxonomy of schizoaffective disorder suggest a stronger relationship with schizophrenia, although the relationship with affective disorder remains unclear.