Work productivity loss with depression, diagnosed and undiagnosed, among workers in an Internet-based survey conducted in Japan.

Abstract

The aim of this study was to investigate whether depression severity was associated with work impairments, regardless of the diagnosis. We conducted a cross-sectional study among 17,820 Japanese workers using an Internet-based survey. Work impairments were assessed using the Work Productivity and Activity Impairment questionnaire. Participants were grouped according to whether they had a past-year diagnosis of depression by physicians and current depression severity assessed with the Patient Health Questionnaire-9. Among the undiagnosed, high severity respondents had greater overall work impairment than low severity respondents (33.3% vs 14.8%). Significant interactions between diagnosis and severity indicated greater impairments among undiagnosed than among diagnosed respondents (except on absenteeism). Depression severity was associated with work productivity loss, even among the undiagnosed, suggesting a need for early detection, referral, and treatment of depression in the workplace.