Background: The association between depression and mortality in older community-dwelling populations is still unresolved. This study determined the effect of both minor and major depression on mortality and examined the role of confounding and explanatory variables on this relationship.
Methods: A cohort of 3056 men and women from the Netherlands aged 55 to 85 years were followed up for 4 years. Major depression was defined according to DSM-III criteria by means of the Diagnostic Interview Schedule. Minor depression was defined as clinically relevant depression (defined by a Center for Epidemiologic Studies Depression score > or = 16) not fulfilling diagnostic criteria for major depression.
Results: After adjustment for confounding variables (sociodemographics, health status), men with minor depression had a 1.80-fold higher risk of death (95% confidence interval, 1.35-2.39) during follow-up than nondepressed men. In women, minor depression did not significantly increase the mortality risk. Irrespective of sex, major depression was associated with a 1.83-fold higher mortality risk (95% confidence interval, 1.09-3.10) after adjustment for sociodemographics and health status. Health behaviors such as smoking and physical inactivity explained only a small part of the excess mortality risk associated with depression.
Conclusion: Even after adjustment for sociodemographics, health status, and health behaviors, minor depression in older men and major depression in both older men and women increase the risk of dying.