The Influence of Psychosis and Emotional Reactivity on Cognitive Flexibility within Bipolar Disorder

Background: Bipolar Disorder (BD) is a chronic mood disorder characterized by severe pathological mood swings. Deficits in cognitive flexibility, impairment in the ability to generate multiple ideas simultaneously, consider alternative responses and alter behaviors based on changing circumstances, have been associated with poor social and work functioning in BD; however, the features of BD that contribute to these deficits remain undefined. Identifying the features of BD that contribute to cognitive inflexibility will aid in effectively remediating these deficits and improving quality of life.  The present study examines the influence of chronic psychosis, current mood symptoms, age, education and emotional processing on cognitive flexibility in a sample of individuals with BD. 

Methods: Participants were originally recruited to participate in a naturalistic, longitudinal study of BD with an initial evaluation using the Diagnostic Interview for Genetic Studies (DIGS). The current study included 36 individuals (ages 18-60) with bipolar I disorder (BD) to participate in a cross-sectional study. Two cognitive flexibility measures, the Wisconsin Card Sorting Test (WCST), a commonly used clinical test, and the Emotion Card Sorting Test (ECST), an emotionally-valenced version of the WCST, were administered and self-report measures of mood were completed (Beck Depression Inventory, BDI; Altman Mania Rating Scale, Altman). Psychosis chronicity obtained from the DIGS interview was based on number of mood episodes that included psychosis: 1) no psychosis during mood episodes (BDn), 2) 1 episode only (BDp1), 3) 2 or more episodes with psychosis (BDp2+). Analyses were conducted using multiple linear regressions to predict the influence of age, education, depression, mania, and chronicity of psychosis on WCST and ECST performance. The independent variables (age, education, depression, mania and psychosis chronicity) were included to predict the performance on each task and to estimate percentage variance accounted for by variables of interest. 

Results: The strongest predictor of cognitive flexibility deficits in BD is chronicity of psychosis above all of demographic and clinical variables for ECST. Although education, age and current depressive symptoms accounted for some of the variance in predicting cognitive flexibility, psychosis chronicity accounted for the greatest amount of variance (β=.49, p<.05) in the emotionally-valenced measure of cognitive flexibility, ECST. None of the predictors were found to be significant for WCST.

 Conclusions: These results indicate that BD individuals with a history of psychosis demonstrated significantly poorer cognitive flexibility on the ECST versus the WCST. Those individuals with BD who have a history of chronic psychosis have difficulty altering or adapting their thoughts and behavioral responses in a changing environment in the context of emotional stimuli. These findings suggest that targeting and treating initial psychotic symptoms may prevent further decline in functioning. Therefore, early interventions before the course of the illness progresses could potentially prevent cognitive impairment and mitigate functional outcomes.