Background: This study assesses depression among primary care patients, the relationship between depression and functioning, and how frequently depressed individuals receive mental health treatment. Methods: Two hundred and thirteen participants completed a diagnostic interview and measures of functional impairment and service utilization. Results: Sixty-two clinic patients were depressed, and depressed individuals experienced significant functional impairment even after controlling for comorbid anxiety disorders and medical problems. However, less than 40% of depressed individuals were receiving treatment for depression. Severity of impairment was related to likelihood of receiving mental health services. Limitations: Several factors to consider when evaluating this study are the cross-sectional design, use of self-report data, and lack of random sampling. Conclusions: These results show that depression has a unique and significant impact on the functioning of primary care patients, and emphasize the need for identification of depressive disorders in primary care. (C) 1999 Elsevier Science B.V. All rights reserved.