A large, long-running European study, involving 3,428 male patients aged 45-74 years, has found that depression is a major risk factor for cardiovascular disease. The risk is almost as great as that due to high cholesterol levels or obesity.
Ladwig, KH. et al. (2016): Room for depressed and exhausted mood as a risk predictor for all-cause and cardiovascular mortality beyond the contribution of the classical somatic risk factors in men. Atherosclerosis, doi: 10.1016/j.atherosclerosis.2016.12.003