Major depression and physical illness. Special considerations in diagnosis and biologic treatment.

Major depression is a painful and debilitating condition that often occurs in association with severe physical illness. Accurate diagnosis is problematic because sadness is a frequent "normal" reaction to physical illness and because many other symptoms of depression, such as anorexia and fatigue, can also be caused by the physical illnesses themselves. We review the clinical research that helps to clarify these diagnostic issues and present guidelines for the diagnosis and biologic treatment of patients with concomitant major depression and physical illness.