Cognitive impairment but preservation of sexual dimorphism in cognitive abilities in chronic schizophrenia

Neurocognitive impairment in schizophrenia is well established, though sex differences on cognitive tasks have produced equivocal findings. The present study was designed to examine performance of schizophrenia patients on a sexually dimorphic cognitive battery. The cognitive battery comprising tests of spatial (mental rotation, computerized version of the Benton Judgment of Line Orientation) and verbal abilities (phonological and semantic fluency) was administered to men (n = 22) and women (n = 21) with schizophrenia and healthy controls (n = 21 men and 21 women). A series of multivariate analyses showed that the patient group performed worse than controls on all the cognitive tasks. Cognitive sexual dimorphism on all spatial tasks favoring men and verbal tasks favoring women remained. Within the patient sample, correlational data demonstrated that earlier age at onset of illness related to poorer spatial performance. It is concluded that normal sexual dimorphism is undisturbed on both spatial and verbal tasks by the schizophrenia disease process.