Background: Depression is one of the most common medical disorders seen in primary care practice. The purpose of this study was to estimate the prevalence of depressive symptoms in primary care patients across the United States, and to describe patient characteristics that may be associated with an increased likelihood of those symptoms.
Methods: Survey data were obtained from a sample of 75,858 patients who visited one of 765 participating primary care physicians for any reason from February 1991 to September 1991. The outcome measurement used was the index score for presence of depressive symptoms on the Zung Self-rating Depression Scale.
Results: The overall prevalence of clinically significant depressive symptoms was found to be 20.9%, but the percentage of patients citing depression as a reason for visit (1.2%) was markedly lower. Patients who perceived their health as poor were more likely to have severe depressive symptoms than patients who perceived their health as excellent. Women, those in older age groups, and those with lower levels of education were more likely to have clinically significant depressive symptoms than men, those in younger age groups, and those with higher levels of education. When classified by marital status within each sex, married men and women were the least likely to have clinically significant depressive symptoms.
Conclusions: Clinically significant depressive symptoms are highly prevalent in primary care patients; however, depression is an infrequent patient complaint. There are certain patient characteristics that may cue the physician to consider depression in the differential diagnosis, particularly the patient's self-perception of his or her overall health status. In addition, certain other subsets of patients are at increased risk of depression, such as women, those in older age groups, and those of lower socioeconomic status.