Social support is assumed to protect mental health, but it is not known whether low social support at work increases the risk of common mental disorders or antidepressant medication. This study, carried out in Finland 2000–2003, examined the associations of low social support at work and in private life with DSM-IV depressive and anxiety disorders and subsequent antidepressant medication.

Social support was measured with self-assessment scales in a cohort of 3429 employees from a population-based health survey. A 12-month prevalence of depressive or anxiety disorders was examined with the Composite International Diagnostic Interview (CIDI), which encompasses operationalized criteria for DSM-IV diagnoses and allows the estimation of DSM-IV diagnoses for major mental disorders. Purchases of antidepressants in a 3-year follow-up were collected from the nationwide pharmaceutical register of the Social Insurance Institution.

Low social support at work and in private life was associated with a 12-month prevalence of depressive or anxiety disorders (adjusted odds ratio 2.02, 95% CI 1.48–2.82 for supervisory support, 1.65, 95% CI 1.05–2.59 for colleague support, and 1.62, 95% CI 1.12–2.36 for private life support). Work-related social support was also associated with subsequent antidepressant use.

This study used a cross-sectional analysis of DSM-IV mental disorders. The use of purchases of antidepressant as an indicator of depressive and anxiety disorders can result in an underestimation of the actual mental disorders.

Low social support, both at work and in private life, is associated with DSM-IV mental disorders, and low social support at work is also a risk factor for mental disorders treated with antidepressant medication.