Epidemiology and diagnosis of depression in late life.

Depression is a significant concern in elderly patients. Reported prevalence rates differ greatly depending on the definition of depression and the population of interest, with increases reported in settings where comorbid physical illnesses are more common. In community-dwelling elderly patients, prevalences of depressive symptoms and major depressive disorder are 15% and 1% to 3%, respectively. Factors associated with depression in the elderly include female gender, alcohol and substance abuse, pharmaceuticals, family history, and medical conditions such as stroke, Alzheimer's disease, cancer, and heart disease. Recognition of depression is complex because patients often deny their depression, present with somatic complaints, or may have comorbid anxiety or cognitive impairment. Depression is underrecognized and undertreated in the elderly, despite evidence that the benefits of treatment outweigh potential risks.