Depression and health-related quality of life.

Chronic medical conditions drastically affect the lives of those afflicted, leading to pain, disability, and disruption. Comorbid depression can exacerbate the effects of medical illness and may be an independent source of suffering and disability. Data from the Epidemiological Follow-Up Study (NHEFS) of the first National Health and Nutrition Examination Survey (NHANES I) are used to examine the manner in which depression and comorbid medical conditions interact to affect health-related quality of life (HRQOL).