PURPOSE Depression is associated with lowered work functioning, including absences, impaired productivity, and decreased job retention. Few studies have examined depression symptoms across a continuum of severity in relationship to the magnitude of work impairment in a large and heterogeneous patient population, however. We assessed the relationship between depression symptom severity and productivity loss among patients initiating treatment for depression.

METHODS Data were obtained from patients participating in the DIAMOND (Depression Improvement Across Minnesota: Offering a New Direction) initiative, a statewide quality improvement collaborative to provide enhanced depression care. Patients newly started on antidepressants were surveyed with the Patient Health Questionnaire 9-item screen (PHQ-9), a measure of depression symptom severity; the Work Productivity and Activity Impairment (WPAI) questionnaire, a measure of loss in productivity; and items on health status and demographics.

RESULTS We analyzed data from the 771 patients who reported being currently employed. General linear models adjusting for demographics and health status showed a significant linear, monotonic relationship between depression symptom severity and productivity loss: with every 1-point increase in PHQ-9 score, patients experienced an additional mean productivity loss of 1.65% (P <.001). Even minor levels of depression symptoms were associated with decrements in work function. Full-time vs part-time employment status and self-reported fair or poor health vs excellent, very good, or good health were also associated with a loss of productivity (P <.001 and P=.045, respectively).

CONCLUSIONS This study shows a relationship between the severity of depression symptoms and work function, and suggests that even minor levels of depression are associated with a loss of productivity. Employers may find it beneficial to invest in effective treatments for depressed employees across the continuum of depression severity.