Purpose: We examined 10 job characteristics in a large population-based sample and tested for positive and negative effects on mental health. In addition, we tested for possible effects on mental health from interactions with locus of control and self-esteem.
Methods: The sample comprised longitudinal data on 2353 male and 1960 female employees from the German socio-economic panel collected between 2010 and 2012. Mental health was assessed with the mental component summary score derived from the short-form 12 health survey. We computed hierarchical regression analyses while controlling for potential confounds and baseline mental health. Interaction effects were specified with post hoc simple slope analyses.
Results: Time pressure, interruptions, job insecurity, and conflicts were negative predictors of mental health in all models. The personal resource of self-esteem was a positive predictor. Moreover, there were interactions: opportunities for promotion were beneficial only for employees with medium or high levels of self-esteem, whereas the contrary was true for employees with very low self-esteem. Working on weekends was negatively related to mental health for people with moderate to low internal control but not for people with high internal control.
Conclusions: The findings suggest that there are job demands that are related to poor mental health regardless of personal resources. These aspects are important to consider in workplace risk assessment. By contrast, with other job characteristics (e.g., opportunities for promotion, weekend work), the effects vary between individuals.
Keywords: Interactive effects; Job demands; Job resources; Locus of control; Mental health; Self-esteem.