This study examines the longitudinal relationships between a health-related quality of life measure and depressive symptoms in patients with major depression. One hundred eighteen patients with primary major depression and 81 controls were evaluated. The patients were divided into three groups based on Diagnostic Interview Schedule criteria for a major depressive episode at baseline (T1) and 6 months later (T2). Results indicate that the Quality of Well-Being (QWB) measure is sensitive to different levels of depressive symptoms over a 6-month period. The QWB is a health-related quality of life and cost/utility measure that may be useful for pharmacoeconomic analysis. The reduction in quality of life associated with symptoms of depression is comparable to that observed with chronically physically ill patients. As a generic symptom/function measure, the QWB may be very useful in evaluating public health policy.