Sex differences in cognitive function among patients with bipolar disorder

TL;DR

This study explores how sex influences cognitive function in patients with bipolar disorder, finding that males and females show different patterns of cognitive impairment.

Contribution

The study identifies sex-specific cognitive vulnerabilities in newly diagnosed bipolar disorder patients.

Findings

Male bipolar disorder patients showed higher deficits in cognitive transferability and attention stability compared to females.

Female bipolar disorder patients exhibited greater memory impairments compared to males.

Cognitive impairments were observed in both male and female bipolar disorder patients compared to healthy controls.

Abstract

Bipolar disorder (BD) is a severe mental illness characterized by high recurrence rates and notable cognitive deficits. Although sex differences are known to influence the clinical characteristics of BD, their specific impact on cognitive function remains unclear. This study aimed to examine the role of sex in shaping cognitive profiles within a large sample of BD patients.

The sample included 243 individuals, 168 patients with first-diagnosed bipolar disorder (107 males and 61 females) and 75 healthy controls (44 males and 31females). Cognitive functions were assessed using the Continuous Performance Test (CPT), the Digital Span Test (DST), and the Wisconsin Card Sorting Test (WCST). Cognitive performance was compared between patient groups and healthy control groups.

Compared with female patients, the total scores of PPE and DST in male patients were significantly higher in the BD group. There were significant main effects of group on CPT, DST, and WCST. There were significant main effects of group and sex for total administered (TA) and non-perseverative errors (NPE) (all with p-value of <0.05). The TA and NPE of male patients are significantly higher than female patients. Among male subjects, the TA and NPE scores of BD patients were significantly higher than healthy controls. Among female subjects, the NPE score of BP patients was significantly higher than healthy controls. The hospital admission frequency was significantly and negatively correlated with attention function scores.

Both male and female patients with BD exhibit cognitive impairment. Sex appears to play a crucial role in cognitive function among first-diagnosed patients with bipolar disorder. Male patients may be more vulnerable to deficits in cognitive transferability and attention stability, whereas female patients may be more susceptible to memory impairments.

Figures