Depression and physical illness among elderly general medical clinic patients.

In this study we conducted a resurvey at 33 months of elderly general medical clinic outpatients previously classified as depressed or not using the Zung Self-Rating Depression Scale. Resurvey results and review of medical records permitted characterization of the point prevalences of depression at the time of the initial and follow-up surveys, and identification of physical illness factors associated with depression. The point prevalences of depression were approximately equal (20%), although only about 10% were depressed at both occasions. Among the initially nondepressed, the number of new physical diagnoses during follow-up was the best predictor of depression at retest. Other factors associated with depression at one or both occasions were: alcohol abuse, obstructive pulmonary disease, and a relatively greater number of medical diagnoses. Thus, among elderly outpatients, depression appears common with roughly equal rates of remission and incidence; also, new medical illness may precipitate depression.