Depression affects an estimated 15% to 19% of Americans ages 65 and older living in a variety of settings, yet the illness often goes unrecognized and untreated. Known risk factors for older adults include having chronic medical conditions, physical or cognitive functional decline, polypharmacy, experiencing multiple losses, and social isolation. There are brief screening tools that have proven effective in this population, and once recognized, depression is highly treatable. This article describes the signs and symptoms common in older adults, outlines several types of depressive disorders, discusses screening tools, describes treatment modalities, and addresses nursing implications.