Sex differences in cognitive reserve among first episode of psychosis patients

Abstract

Introduction: Cognitive reserve (CR) has recently been considered a key factor in the onset of a first episode of psychosis (FEP). However, the differences in CR in FEP patients according to sex have not yet been investigated.

Material and methods: CR was estimated among 443 FEP patients (246 men and 197 women) and 156 healthy controls (96 men and 60 women) by using the proxies premorbid IQ, years of education and employment status. A neuropsychological battery was administrated to measure neurocognitive specific domains. Analyses of variance were used to make comparisons between groups.

Results: FEP women had greater CR than FEP men. This circumstance was not observed in healthy controls. Among the group of patients with low CR, FEP women outperformed FEP men in the cognitive domains verbal memory and processing speed. Meanwhile, among the FEP patients with high CR, men showed better performance in attention than women.

Conclusions: Differences in CR observed between FEP men and women could be related to a number of specific factors, such as, age at illness onset, education level, and variability in performance in verbal memory, processing speed, and attention domains. These results provide background information about CR in FEP patients that will be useful in the design of sex specific cognitive remediation interventions.

Keywords: Cognitive domains; Cognitive reserve; First episodes of psychosis; Neurocognition; Sex.