Objectives. We addressed whether repeated job strain and low work social support increase the risk of major depressive disorder (MDD).
Methods. We used work characteristics from Karasek’s Job Strain model, measured on 3 occasions over 10 years in a cohort of 7732 British civil servants, to predict subsequent onset of MDD with the Composite International Diagnostic Interview.
Results. Repeated job strain was associated with increased risk of MDD (odds ratio [OR] = 2.19; 95% confidence interval [CI] = 1.48, 3.26; high job strain on 2 of 3 occasions vs none) in a fully adjusted model. Repeated low work social support was associated with MDD (OR = 1.61; 95% CI = 1.10, 2.37; low work social support on 2 of 3 occasions vs none). Repeated job strain remained associated with MDD after adjustment for earlier psychological distress.
Conclusions. Demonstration of an increased association for repeated job strain adds to the evidence that job strain is a risk factor for depression. Recognition and alleviation of job strain through work reorganization and staff training could reduce depression in employees.