1. ¹Department of Psychiatry and Psychology, Center for Cognitive Medicine, University of Illinois at Chicago, Chicago, IL, USA
2. ²Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
3. ³Department of Psychiatry, Wayne State University School of Medicine, Detroit, MI, USA

Correspondence: LH Rubin, Center for Cognitive Medicine, Neuropsychiatric Institute, University of Illinois at Chicago, 912 S. Wood Street MC913, Chicago, IL 60612, USA. Tel: +1 312 355 5652; Fax: +1 312 413 7856, E-mail: lrubin@psych.uic.edu

Received 24 May 2006; Accepted 15 February 2007; Published online 28 March 2007.

Abstract

We extend the investigation of cognitive sex differences in schizophrenia in a novel way by grouping cognitive tests according to the direction of the typical sex difference, an approach used in studies of hormonal effects on behavior in other clinical conditions. Additionally, we explore how performance on these 'male' and 'female' tests changed following antipsychotic treatment. Seventy patients with a first hospitalization for schizophrenia or schizophreniform disorder completed cognitive tests before antipsychotic treatment and approximately 5 weeks after treatment. Thirty-nine healthy comparison subjects completed the tests at similar intervals. Primary outcome variables were composite scores on cognitive tests that in normative studies favor males over females ('male' tests) or favor females over males ('female tests'). Overall, patients performed more poorly than healthy individuals. The expected pattern of sex differences was found on the composite test scores, with an advantage for females on 'female' tests and an advantage for males on 'male' tests. Female patients showed a greater improvement on 'female' tests and a decrease in performance on 'male' tests following treatment. Although male patients did not perform significantly better after treatment on 'female' tests, they did improve on non-motor 'male' tests of visuospatial skills. Future studies of the neurocognitive effects of antipsychotic treatment may need to take potential sex differences in cognitive response into account.