Depressive symptom clusters are differentially associated with atherosclerotic disease

Background Depression increases the risk of subsequent vascular events in both cardiac and non-cardiac patients. Atherosclerosis, the underlying process leading to vascular events, has been associated with depression. This association, however, may be confounded by the somatic-affective symptoms being a consequence of cardiovascular disease. While taking into account the differentiation between somatic-affective and cognitive-affective symptoms of depression, we examined the association between depression and atherosclerosis in a community-based sample.Method In 1261 participants of the Nijmegen Biomedical Study (NBS), aged 5070 years and free of stroke and dementia, we measured the intimamedia thickness (IMT) of the carotid artery as a measure of atherosclerosis and we assessed depressive symptoms using the Beck Depression Inventory (BDI). Principal components analysis (PCA) of the BDI items yielded two factors, representing a cognitive-affective and a somatic-affective symptom cluster. While correcting for confounders, we used separate multiple regression analyses to test the BDI sum score and both depression symptom clusters.Results We found a significant correlation between the BDI sum score and the IMT. Cognitive-affective, but not somatic-affective, symptoms were also associated with the IMT. When we stratified for coronary artery disease (CAD), the somatic-affective symptom cluster correlated significantly with depression in both patients with and patients without CAD.Conclusions The association between depressive symptoms and atherosclerosis is explained by the somatic-affective symptom cluster of depression. Subclinical vascular disease thus may inflate depressive symptom scores and may explain why treatment of depression in cardiac patients hardly affects vascular outcome.