This systematic review and meta-analysis aimed to examine whether working beyond the standard working hours was associated with a greater risk of depressive disorder among workers included in published prospective studies. This manuscript was prepared according to the PRISMA guideline checklist. A database search was conducted using MEDLINE (PubMed), PsycINFO, and PsycARTICLES using a relevant set of keywords. The eligibility criteria were as follows: (1) participants were adult workers; (2) exposure was defined as overtime work; (3) outcome were depressive disorders clinically diagnosed or assessed by a structured interview and (4) the study design was prospective or cohort. 7 studies were identified in the systematic review and meta-analysis. Overtime work was associated with a small, non-significant, elevated risk of depressive disorder (pooled relative risk=1.075; 95% CI 0.834 to 1.387; p=0.575) in a random effects model. The association tended to be greater for women. The risk of working 50 or more hours per week was slightly but not significantly increased (pooled relative risk=1.241; 95% CI 0.880 to 1.750; p=0.218). The effect of overtime work on depressive disorder remains inconclusive and may be small if not negligible. Sex differences and the effect of longer working hours on depressive disorder should be addressed in the future.

Trial registration number Prospero CRD42015020003; Results.