[Depression: clinical features and consequences among the elderly].

Among geriatric syndromes, chronic and recurrent depression is salient due to its ravaging effects. Depression is a predisposing factor for chronic diseases and decreases functional status. In the United States, depression alone represents a forty three billion dollar annual expense. Although the prevalence of depression may vary depending on the population studied and the methodology applied, its range is between 10 to 27%. Fatigue, insomnia, and anorexia, in a cyclical fashion, are the milestone symptoms of depression among the elderly. Nevertheless, these symptoms have poor diagnostic specificity, mainly because they may be observed among healthy elders; thus the importance of using reliable screening tools that allow early detection. In order to shed light on this disease, the present article reviews its clinical course and consequences, and describes the use of the geriatric depression scale as the most popular screening instrument for this patient population.