Background: Previous studies have shown that high effort-reward imbalance (ERI) at work is a risk factor for the onset of self-reported depressive symptoms. In this study, we examined whether ERI predicts risk of treatment with antidepressant medication in a representative sample of the Danish workforce.
Methods: We linked survey data on ERI and covariates of 4541 participants from the Danish Work Environment Cohort Study 2000 with the Danish National Prescription Registry that includes all legally purchased prescription drugs at pharmacies in Denmark since 1995. Participants with a history of antidepressant treatment or with self-reported depressive symptoms at baseline were excluded. Using Cox proportional hazard analyses we examined the prospective association between ERI at baseline and incident antidepressant treatment while adjusting for potential confounders. Time of follow-up was 5 years.
Results: A total of 309 (6.8%) participants started antidepressant treatment during follow-up. Exposure to ERI at baseline was not related to risk of antidepressant treatment (hazard ratio: 0.91, 95% CI=0.81–1.03 after adjustment for potential confounders).
Limitations: The use of antidepressant treatment as an indicator for onset of depression might have led to misclassification, because (a) antidepressants are also used to treat other conditions than depression and (b) a considerable proportion of individuals with depression are not treated with antidepressants.
Conclusions: ERI did not predict incident antidepressant treatment, contradicting previous findings on ERI and self-reported depression. To clarify the association of ERI with risk of depression, we recommend further prospective studies using non-self-reported measures of ERI, clinical assessments of depression, or both.