THE CLINICAL PROBLEM
Late-life depression is the occurrence of major depressive disorder in adults 60 years of age or older. Major depressive disorder occurs in up to 5% of community-dwelling older adults, and 8 to 16% of older adults have clinically significant depressive symptoms.1 Rates of major depressive disorder rise with increasing medical morbidity, with reported rates of 5 to 10% in primary care2 and as high as 37% after critical care hospitalizations.3
Patients with late-life depression are heterogeneous in terms of clinical history and coexisting medical conditions. As compared with older adults reporting an initial depressive episode early in life, those with late-onset depression are more likely to have neurologic abnormalities, including deficits on neuropsychological tests and age-related changes on neuroimaging that are greater than normal; they are also at higher risk for subsequent dementia. 4 Such observations informed the hypothesis that vascular disease may contribute to depression in some older adults