Sex differences in neurocognitive and psychosocial functioning in bipolar disorder

Abstract

Background: Sex differences influence the clinical characteristics and course of illness of bipolar disorder (BD).

Objective: Therefore, the aim of the present study was to examine the role of sex differences in neurocognitive performance and psychosocial functioning in a large sample of euthymic patients suffering from BD.

Methods: The sample included 462 individuals, 347 patients with BD (148 males and 199 females) and 115 healthy controls (HC) (45 males and 70 females). Performance on a comprehensive neuropsychological battery assessing six cognitive domains and psychosocial functioning was compared between groups using linear mixed models, with sex and group as main effects, group by sex interactions and center as a random effect.

Results: Males performed better than females in working memory (p < 0.001), whereas females outperformed males in the verbal learning (p = 0.03) and memory recognition (p = 0.03) tasks. No significant group by sex interactions were detected in cognitive performance. There were no overall sex differences or group by sex interactions in psychosocial functioning.

Limitations: Lack of assessment of visuo-spatial working memory.

Conclusions: There were no overall sex differences in neurocognition and psychosocial functioning. However, small sex differences in some measures of working memory and verbal memory were found. Individual differences of each patient, including sex perspective, should be considered in order to perform a tailored intervention plan adjusted to specific needs in the context of personalized treatment.

Keywords: Bipolar disorder; Cognition; Psychosocial functioning; Sex differences.