In addition to serious human suffering, mental disorders result in work impairment.1 2 The costs of mental disorders, particularly depression, to employers in terms of lost work days and reduced productivity is substantial.3 Studies from several countries report an increase in work stress,4 and that mental disorders, especially depression, are growing reasons for work disability and early retirement.5 6 The question about psychosocial work characteristics as risk factors for depression has attracted increasing interest among researchers. A recent meta-analysis provided evidence that high demands and low decision latitude, high effort-reward imbalance, and low social support at work from co-workers and supervisors are risk factors for common mental disorders.7

A major methodological limitation in earlier studies on psychosocial work characteristics and mental health is related to bias due to response …