Explanations of educational differences in major depression and generalised anxiety disorder in the Irish population.

BACKGROUND Social inequalities in mental disorders have been described, but studies that explain these inequalities are lacking, especially those using diagnostic interviews. This study investigates the contribution of various explanatory factors to the association between educational level and major depression and generalised anxiety disorder in Irish men and women. METHODS The study population comprised a national random sample of 5771 women and 4207 men aged 18 or more in Ireland (SLÁN 2007 survey). Major depression and generalised anxiety disorder were measured using a standardised diagnostic interview (CIDI-SF). Four groups of explanatory factors were explored: material, psychosocial, and behavioural factors, and chronic disease. RESULTS For both genders, low educational level increased the risk of both mental disorders. Material factors, especially no private health insurance, but also no car, housing tenure, insufficient food budget, and unemployment (for men), made the highest contribution (stronger for men than for women) in explaining the association between education and both mental disorders. Psychosocial (especially formal social participation, social support and marital status) and behavioural factors (smoking and physical activity for both genders, and alcohol and drug use for men) and chronic disease made low independent contributions in explaining the association between education and both mental disorders. LIMITATIONS Given the cross-sectional study design, no causal conclusion could be drawn. CONCLUSIONS Targeting various material, psychosocial, and behavioural factors, as well as chronic diseases may help to reduce educational differences in depression and anxiety in the general population.