BACKGROUND: During the last few years, a high incidence of sick leave due to depression has been reported, resulting in important economic and social impacts. Only a limited number of studies investigating the influence of psychosocial working conditions on sick leave have been prospective and have utilised a valid methodology, while none have studied sick leave due to depression. In this study, the impact of adverse psychosocial working conditions is analysed on the risk for long-term sick leave due to depression. METHODS: This study resulted from the large-scale Belstress I study on the relationship between perceived job stress and health problems. Subjects were Belgian employees selected from 11 large companies (n = 9396). Using a longitudinal design, the association between the three Karasek stress dimensions (job control, psychological demand, and social support) was explored, separately and combined according to the demand-control and demand-control-support models and the incidence of long-term sick leave for depression as diagnosed by the family physician. RESULTS: After adjusting for age, occupational categories, living situation, and baseline depression score, 'passive jobs' (OR 2.67; 95% CI 1.15 to 6.19) and 'high strain' jobs (OR 3.23; 95% CI 1.40 to 7.43) predicted sick leave due to depression at follow-up in men. Job control predicted sick leave due to depression in both men (OR 2.43; 95% CI 1.27 to 4.66) and women (OR 2.21; 95% CI 1.05 to 4.68). CONCLUSIONS: This study provides evidence that the psychosocial working environment influences long-term sick leave due to depression. Efforts to improve skill discretion and decision authority at work could help prevent depression. ; Journal Article ; info:eu-repo/semantics/published