Psychosocial work environment and hospital admissions due to mental disorders: A 15-year prospective study of industrial employees

Background: Low levels of job control and social support may increase the risk of mental disorders, particularly depression, but the evidence is mostly based on self-reports. We examined whether components of job control and work-related social support predict medically-certified mental disorders. Methods: 13868 forest company employees with no previous hospital admissions for mental disorders responded to questionnaires on decision authority, skill discretion, co-worker and supervisor support. They were followed-up for hospital admissions due to mental disorders (ICD-9 codes 290 to 319), using national hospital discharge records (577 hospitalized, mean follow-up 15.1 years). Results: In analyses adjusted for confounders, high skill discretion was associated with a reduced risk of hospital admission for mental disorders (HR 0.74, 95% CI 0.58-0.95). High decision authority was associated with an elevated risk (HR 1.48.95% CI 1.17-1.87). Diagnosis-specific analyses showed high skill discretion to associate with a reduced risk of both depressive and non-depressive non-alcohol-related mental disorders. High decision authority was a risk factor for alcohol-related and depressive disorders. Good co-worker support was associated with a reduced risk of non-depressive non-alcohol-related mental disorders. Supervisor support was not associated with any mental disorders. Limitations: We used a single time point estimate in an industrial sample comprising largely of men. Conclusions: Contrary to previous research on job control, high decision authority increased the risk of depressive and alcohol-related disorders, which suggest a need to reconsider the strategies for prevention and clinical practise in regard to psychosocial work environment and mental health. (C) 2009 Elsevier B.V. All rights reserved.