Purpose <p>Previous prospective findings of elevated risk of depression following exposure to stressful work in terms of effort-reward imbalance (ERI) were based on a single exposure measurement. With this study, we set out to analyse longitudinal associations of single and twofold exposure measurement with depression among middle-aged employees.</p> Methods <p>Data were derived from the first two waves (2011 and 2014) of the prospective lidA cohort study in Germany, including 3,104 middle-aged employed men and women. Participants with depression at baseline were excluded. Work stress (effort-reward ER) ratio and work-related over-commitment (WOC) and depression (Beck’s Depression Inventory) were assessed at both waves. Time-invariant (birth year, sex, education) and time-varying covariates (employment, control, physical health) were adjusted for. Multiple logistic regression analyses were conducted to estimate the odds of depression for single or twofold high exposure, and generalized estimation equations (GEE) to analyze mean associations between moderate and high exposure and outcome over both waves.</p> Results <p>5.9% of male and 9.8% of female participants experienced depression during the observation period. Cases were more frequent among those scoring high on work stress measures, those with poor physical health and part-time work. In the fully adjusted GEE model, the estimated risk ratio of depression was 1.60 (95%-CI: 1.05; 2.44) for moderate and 2.49 (1.67; 3.71) for high exposure to ERI work stress on average over time. Similar effects were observed for WOC.</p> Conclusion <p>Elevated risk ratios of depression were observed in associations with moderate and high exposure to stressful work (ERI) over time.</p>