The prevalence of MD in patients with CHD is high. An independent association has been found between major depression (MD) and coronary heart disease (CHD). Numerous cardiovascular diseases have been associated with alterations in the nitric oxide (NO) system, such as hypertension, heart failure, and coronary artery disease. The mechanisms explaining the association between MD, increased platelet reactivity, and endothelial dysfunction, along with their impact on increased cardiovascular risk, remain to be determined.