Associations Between Depressive Symptoms, Cognitive Impairment, and Work Productivity Loss in Patients With Bipolar Disorder: A 48‐Week Longitudinal Analysis

Aim To examine the relationships among work productivity loss and changes in depressive symptoms and cognitive impairment in patients with bipolar disorder and to investigate the relationship between bipolar disorder symptoms and work productivity loss. Methods This prospective, 48‐week, longitudinal, web‐based, cohort questionnaire study included adults with bipolar disorder in Japan who were employed or on sick leave. Questionnaire surveys including validated self‐administered rating scales assessing cognitive impairment, work productivity loss, quality of life (QOL), depressive symptom severity, and sleep disturbance were completed every 12 weeks from baseline through Week 48. The primary endpoint was the correlation between change from baseline at 48 weeks in cognitive impairment and work productivity loss. Secondary endpoints included change from baseline in each symptom score, cognitive impairment, work productivity loss, depressive symptoms, QOL, and sleep disturbance. Results Of 211 study participants, 179 responded to all the study questionnaires and were included in this 48‐week analysis. There was a weak correlation between change in cognitive impairment and change in work productivity loss (presenteeism) from baseline to Week 48 (Pearson correlation coefficient = 0.304, p = 0.001), but the multiple regression analysis showed no association. Change in work productivity loss was significantly associated with change in depressive symptoms (regression coefficient = 2.43, p < 0.001). Change in QOL was significantly associated with change in insomnia (regression coefficient = −0.01, p < 0.05) in multiple regression analyses. Conclusion Treating patients with bipolar disorder to improve depressive symptoms and cognitive impairment may benefit work productivity.