Long working and commuting times as risk factors for depressive symptoms. Cross-sectional and longitudinal analyses

Abstract

Background: Regular long working and commuting hours are thought to have negative consequences for mental health. However, the study results are not clear and vary by country. The present analysis examines associations between working or commuting hours and depressive symptoms for Germany. Method: The S-MGA study (German Study on Mental Health at Work) is a longitudinal cohort of a random sample of employees subject to social insurance contributions. We analysed data from 3 413 participants of the baseline survey (cross-sectional analysis) and from 2 019 people who participated at baseline and at a follow-up survey five years later (longitudinal analysis). Weekly working and commuting hours as well as covariates (age, gender, occupational position, psychosocial working conditions) were collected at baseline. Depressive symptoms were recorded with the Patient Health Questionnaire at both waves. Multivariate logistic regression models were used to control for covariates. Results: At baseline survey, 7 % of the employees had overlong working hours of ≥ 55 hours per week, and another 8 % worked > 48-54 hours. Long working hours were cross-sectionally associated with moderately elevated depressive symptoms compared to normal working hours (35-< 40 h/week). When new depressive symptoms after five years were considered, the correlation was significant for > 55 weekly working hours (odds ratio [OR] 2.14; 95 % confidence interval [CI] 1.11;4.12), but not for > 48-54 h (OR 1.26, CI 0.65;2.43). Employees who commuted ten hours or more per week had more depressive symptoms cross-sectionally (OR 1.83; CI 1.13;2.94) compared to the reference group who commuted < 2.5 hours. This correlation was not observed longitudinally. Conclusions: The results suggest that excessive working and commuting time is associated with depressive symptoms in employees, although the effects of commuting time were only found cross-sectionally. The results underline the importance of adhering to working time regulations and avoiding excessive working hours. Further research is needed on the role of commuting.