Depressed patients are known to manifest a variety of neuroendocrine changes that predispose to coronary artery disease including hypercortisolism, decreased secretion of growth hormone and a deficiency of sex steroids. A final common denominator of these neuroendocrine abnormalities is insulin resistance. Insulin resistance promotes several changes that would favor hypertension and increased coronary artery disease including increased sodium retention, increased activity of the sympathetic nervous system, proliferation of vascular smooth muscle and deposition of highly metabolically active visceral fat. The latter induces additional risk factors for coronary disease, including dyslipidemia, hypercoagulation, and enhanced inflammation. It is a matter of public health importance to document the frequency and severity of insulin resistance in patients with major depression compared to a closely matched group of healthy controls. To accurately quantify insulin resistance in each patient and control, we will apply the hyperinsulinemic euglycemic glucose clamp procedure. This is the gold standard method for measuring the insulin sensitivity since it reflects the direct human body glucose metabolic response to a known insulin infusion. Moreover, it is essential to use this technique in patients with major depression as data indicate that other alternative procedures give unreliable results in the context of hypercortisolism.