Associations between overcommitment, effort–reward imbalance and mental health: findings from a longitudinal study

Purpose: The effort–reward imbalance (ERI) model includes extrinsic and intrinsic aspects of work stress. The single components, ERI and overcommitment (OC), are known to be associated with mental health. The aim of this study was to test whether OC is a mediator of the association between ERI and mental health. Methods: Longitudinal analyses were conducted using data from the Third German Sociomedical Panel of Employees on German employees aged 40–54 years. The short version of the ERI questionnaire was used to measure ERI and OC at baseline (2013). Outcomes were mental health problems and self-rated mental health (5-Item Mental Health Inventory) in 2015. Multivariate regressions were conducted controlling for sociodemographics, health-related behaviour, job-related aspects, and mental health at baseline. Results: A total of 912 men and 1148 women were included in the final analysis. Baseline OC was positively associated with follow-up mental health problems and negatively with self-rated follow-up mental health. While there was no direct effect of ERI on mental health, ERI affected mental health problems (b = 0.14; 95% CI 0.03 to 0.25) and self-rated mental health (b = − 1.15; 95% CI − 1.79 to − 0.57) indirectly through OC. Conclusions: OC was associated with reduced mental health. There was no association between ERI and mental health that was independent of OC. OC could therefore be interpreted as a mediator between ERI and mental health. Future studies are needed to test the causality of this association.