Long Working and Commuting Times as Risk Factors for Depressive Symptoms: Cross-Sectional and Longitudinal Analyses

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 in 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 on 3,413 participants of the baseline survey (cross-sectional analysis) and on 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. To investigate associations, odds ratios with 95% confidence intervals were calculated by means of logistic regression. Both cross-sectional (baseline survey only) and longitudinal analyses (baseline and post-survey) were conducted.Results At baseline survey, 7% of the employees had long working hours of >= 55 hours per week, and another 8% worked 49-54 hours. In the cross-sectional analysis, long working hours were 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 49-54 h (OR 1,26, CI 0,65;2,43). Employees who commuted ten hours or more per week had more depressive symptoms in the cross-sectional analysis (OR 1,83; CI 1,13;2,94) compared to the reference group who commuted<2,5 hours. This correlation was not observed in the longitudinal analysis.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 in mental health.