Clinical depression, antidepressant use and risk of future cardiovascular disease

Many studies have shown that depression contributes to a higher risk of developing cardiovascular disease (CVD). Use of antidepressants and its association with CVD development has also been investigated previously but the results have been conflicting. Further, depression and use of antidepressants have been more widely studied in relation to coronary heart disease rather than stroke. A population-based cohort study consisting of 36,654 Swedish elderly twins was conducted with a follow-up of maximum 4 years. Information on exposures, outcomes and covariates were collected from the Swedish national patient registers, the Swedish prescribed drug registry and the Swedish twin registry. Depression and antidepressant use were both associated with CVD development. The risk was most pronounced among depressed patients who did not use antidepressants (HR 1. 48, CI 1.10-2.00). When assessing the two main CVD outcomes coronary heart disease and ischemic stroke separately, the predominant association was found for ischemic stroke while it was absent for coronary heart disease. The association between depression and stroke also remained significant when restricting to depression diagnoses occurring at least 10 years before baseline. The study supports that depression is a possible risk factor for development of CVD. Moreover, the hazard rate for CVD outcomes was highest among depressed patients who had not used antidepressants. The association with clinical depression is more marked in relation to stroke and disappears in relation to development of coronary heart disease.