Gender difference of cognitive impairments in euthymic bipolar disorder

Abstract

Objective The study was to analyze the gender difference of cognitive impairments in euthymic bipolar Ⅰ disorder. Methods This study included 218 euthymic bipolar Ⅰ disorder patients (86 male BD patients, 132 female BD patients) and 318 healthy controls (191 male healthy controls, 127 female healthy controls). The digital symbol, digital span, visual reproduction, trail making test A, trail making test B, Wisconsin test and Tower of Hanoi (TOH) test was used to test their attention function, memory function and executive function. Each subject took the 7 measurements in order to investigate the gender differences between two groups. Results Patients performed significantly worse than healthy controls in digital symbol, digital span forward, digital span backward, digital span total score, trail making test A, trail making test B, visual reproduction, Wisconsin test type, verbal fluency total score, Tower of Hanoi test total score, TOH total task, plan time of TOH, executive time of TOH, WSCT total errors, WSCT continuous errors, repeat numbers of verbal fluency test（F=66.60，16.10，17.06，20.38，98.77，66.33，23.75，5.65，62.08，21.51，22.08，10.15，19.33，χ2=21.53，33.17，12.78，P<0.05）. The main effect of gender was significant in digital symbol (F=8.046, P<0.05) and planning time of TOH test (F=5.053, P<0.05), female［controls(55.38±14.30),patients(47.82±11.95)］ performed better than male ［controls(53.30±12.30),patients(46.14±11.72)］in digital symbol, male［controls(5.28±2.65),patients(6.36±3.77)］ use more time in planning time of TOH test than female［controls(5.15±2.82), patients(5.52±3.07)］, and interaction of group*gender factors had no significant （P<0.05). Conclusion Euthymic bipolar Ⅰ disorder patients′ cognitive functions are impaired in comparison with healthy controls, and there are gender differences in some attention and executive function both in patients and healthy controls with no interaction effect between group and gender. Key words: Bipolar disorder; Cognition; Gender identity