No sex differences in neuropsychological performance in first episode psychosis patients

Objective: The purpose of this study was to verify whether male patients with psychosis have greater neurocognitive impairment than female patients at illness onset. Method: Participants with a first episode of psychosis (74 women/86 men) and healthy controls (62 women/97 men) were assessed with an extensive neuropsychological test battery. Results: Women in the clinical group were older at illness onset and had achieved higher formal education than men. This trend was the same for the control group. The patient group presented with lower premorbid IQ compared to healthy controls, and performed below for most neuropsychological tests. Women scored higher than men on a test of verbal memory, whereas men scored higher than women on a test of reaction time, visual memory, and a planning task. There were no group-by-sex interactions for any of the neuropsychological tests. Conclusion: The present study shows that at the onset of psychosis there are no differences between males and females in neuropsychological performance. The differential pattern of cognitive performance observed is similar to that in healthy males and females. Furthermore, females with a late onset of psychosis may represent a subgroup with specific visuospatial and problem solving impairments. Significant outcomes: 1- The present study does not give support to the hypothesis that male have worse neurocognitive functioning than female patients at illness onset. 2- The neuropsychological profile of sex differences observed among patients is consistent with that observed among controls. 3- We identified a subgroup of female patients with late onset that differed in their degree and pattern of cognitive impairment with regard to their male counterparts. Limitations: 1-Factors other than neurocognitive functioning may underlie the more severe impairment observed in the onset and course of illness in men. 2- Although the study used a broad battery of well established tests, this battery may lack sensitivity to detect sex differences. 3- A longitudinal study is required to further explore whether sex specific deficits require special rehabilitation programs for patients with schizophrenia. (C) 2013 Elsevier Inc. All rights reserved.