Cognitive performance in bipolar disorder: Comparison between individuals with and without suicide attempts and healthy controls

Abstract

IntroductionBipolar disorder (BD) presents an elevated risk of suicide. One hypothesis for this is that cognitive impairments contribute to suicidal behavior. However, the relationship between cognition and suicidal behavior in BD remains unclear. ObjectiveTo compare cognitive performance in individuals with BD with previous suicide attempts vs no attempt vs healthy controls (HC). MethodsWe included 306 participants: 101 individuals with BD (49 with previous suicide attempts and 52 without attempts) and 205 HC. Participants underwent a clinical interview and neuropsychological evaluation. We assessed cognitive performance in social cognition, episodic verbal memory, working memory, processing speed, executive functioning, sustained attention, and intelligence. Afterwards, individuals with BD were separated between groups with and without suicide attempts. We then compared cognitive performance and clinical characteritics between groups. ResultsIndividuals with BD who attempted suicide had more hospitalizations, higher prevalence of psychiatric family history, and overall greater functional impairment. Regarding cognition, HC outperformed both BD groups, with the exception of social cognition and Stroop Color-Word and interference weighted score. However, there were no significant differences in cognitive performance among both BD groups. LimitationsCross-sectional design and dichotomization between suicide attempt vs. no attempt ConclusionsBD with previous suicide attempt present worse clinical outcomes and higher illness severity. Nevertheless, there were no cognitive differences among individuals with BD with and without suicide attempts. Both BD groups may share a vulnerability for cognitive impairment, but not for clinical and functional outcomes. Our results point to significant heterogeneity among clinical and functioning areas of BD.