Cognition and functioning in bipolar depression

Abstract

Objectives: Depressive symptoms are associated with worse outcomes in patients with bipolar disorder (BD). However, scarce data are available regarding neurocognitive profiles across different areas of functioning among BD patients with moderate and severe depression. Our objective was to assess cognition and global functioning in a group of patients with bipolar depression.

Methods: Data were available for 100 patients with bipolar depression (78% female) and 70 controls (64% female) paired by age and education level. Cognitive function was assessed with a neuropsychological test battery. Functioning was assessed with the Functioning Assessment Short Test.

Results: In patients, severe depression was associated with poorer cognitive performance on measures of executive function. Patients with severe depression showed worse global functioning than those with moderate depression (z = 2.54, p = 0.011). In patients with severe depression, lower global functioning was associated with lower scores in working memory (r = -0.200, p = 0.010), and executive function (r = -0.210, p = 0.007; and r = 0.293, p < 0.001).

Conclusion: Our findings suggest cognitive impairment and global functioning impairment are associated with the severity of depressive symptoms in bipolar depression. Intensive treatment of depressive symptoms in patients with BD is crucial to improve cognitive functioning and, consequently, functional outcomes.

Figure 1. Comparison between healthy controls, patients with moderate depression, and patients with severe depression in domains of cognition.

Figure 2. Correlations between domains of cognition and functioning. The y axis represents functioning as measured by the Functioning Assessment Short Test (FAST; the higher the score, the poorer the functioning); the x axis represents standardized scores.