Depression and the risk for cardiovascular diseases: Systematic review and meta analysis

Background: Depression and cardiovascular diseases are both common among elderly. Depression is suspected to be an independent risk factor for the onset of coronary heart disease, yet it is not clear to what extent and if depression also is associated with the onset of other diseases of the circulatory system. Aims: To estimate the risk of depression as an independent risk factor for various cardiovascular diseases (CVD) and explore the effects of heterogeneity and methodological quality. Method: Meta-analyses and meta-regression analyses of longitudinal cohort and case-control studies reporting depression at baseline and CVD outcomes at follow-up. Data sources: MEDLINE (1966-2005) and PSYCHINFO (1966-2005). Results: Of the 28 studies that met the inclusion criteria, 11 were assesed as high quality studies. Although depressed mood increased the risk for a wide range of CVDs, heterogeneity was substantial in most cases. Only the overall combined risk of depression for the onset of myocardial infarctions (n=8, OR=1.60, 95%CI 1.34-1.92) was homogenous. Clinically diagnosed major depressive disorder was identified as the most important risk factor for developing CVD. Conclusions: Depression seems to be an independent risk factor for the onset of a wide range of CVDs, although this evidence is related to a high level of heterogeneity.