Comparative and interactive effects of depression relative to other health problems on work performance in the workforce of a large employer.

OBJECTIVES To present data on the comparative and interactive workplace costs of depression relative to other health problems in the workforce of a large employer. METHODS The World Health Organization Health and Work Performance Questionnaire was used to assess self-reported health problems and work performance. Survey data were linked to medical-pharmacy claims data. Regression analysis was used to assess comparative effects of depression in the absence and presence of comorbidities on Health and Work Performance Questionnaire measures of work performance. RESULTS Depression had the largest individual-level effect on work performance of any condition examined. Several comorbid conditions exacerbated the effect of depression, but had no effects in the absence of depression. CONCLUSIONS Depression is a strong predictor of decrements in work performance. Other conditions that often co-occur with depression, including anxiety and fatigue-sleep disturbance, exacerbate the adverse effect of depression.