Objective: Normal sex differences in language functions are disrupted in schizophrenia. However, identification of specific language components most vulnerable in schizophrenia and how they may differ by sex remain unexamined. The current study investigated this issue in the domains of phonology, semantics, and grammar, which have been closely linked with neuroanatomic regions for which sex differences have been identified.
Method: Thirty-one outpatients with DSM-III-R schizophrenia and 27 healthy subjects comparable within sex on age, handedness, parental socioeconomic status, and ethnicity were systematically ascertained from a Boston catchment area. The subjects were administered an extensive language battery in the context of a comprehensive neuropsychological battery that included measures of phonology, semantics, and grammar.
Results: Male patients performed significantly worse than their healthy counterparts on all three domains, with phonology least affected. In contrast, language function was relatively preserved in the female patients, compared to their healthy counterparts, with phonology most affected. Across domains, the effect sizes in comparisons of male patients and healthy male subjects had a twofold difference, whereas the difference in effect sizes in comparisons of female patients and healthy female subjects was less in all areas.
Conclusions: Findings were consistent with prior evidence of overall language dysfunction in schizophrenia and may have implications for understanding sex differences in neuroanatomic abnormalities in regions associated with phonological processing.