Job stressors and long-term sick leave due to depressive disorders among Japanese male employees: Findings from the Japan Work Stress and Health Cohort study

Background: Research on the association between job strain or other job stressors and depressive disorders is still limited. The purpose of the present study was to investigate the prospective association of job strain, role stressors and job insecurity with long-term sick leave due to depressive disorders. Methods: A prospective study was conducted of a total of 15 256 men aged 18-67 years with no previous history of mental disorders employed in six manufacturing factories located in several regions of Japan. At baseline, they were surveyed using a self-administered questionnaire, including self-reported measures of job strain, as well as its components (job overload and job control), role stressors (role ambiguity and role conflict), social support at work, job insecurity and other demographic and psychological covariates. During the follow-up, a long-term sick leave of 30 days or more due to depressive disorders was recorded. Results: During 5.14 years of follow-up on average, 47 incident cases of sick leave of 30 days or more due to depressive disorders were observed. High job control at baseline was associated with a lower risk of long-term sick leave due to depressive disorders, after adjusting for demographic variables, depressive symptoms and neuroticism at baseline (hazard ratio 0.28, 95% CI 0.11 to 0.71); high role ambiguity was associated with the higher risk (hazard ratio 3.49, 95% CI 1.43 to 8.49). Conclusion: Job control and role ambiguity may be important predictors of long-term sick leave due to depressive disorders among male employees, independent of depressive symptoms and neuroticism.