Overlap of Depressive Symptoms with Health-Related Quality-of-Life Measures.

Because depressive symptoms are a part of health-related quality-of-life (HRQOL) measures, measures of depression will be empirically associated with HRQOL. We discuss examples of published research where authors ignored or did not fully account for overlap between depressive symptom and HRQOL measures. Future researchers need to recognize when their models include conceptually similar variables on the same side or both sides of the equation. This awareness will lead to more accurate conclusions about the prognostic value of depression and other HRQOL measures for health care utilization, mortality, and other outcomes. It will also result in fewer incorrect claims about the effect of depression on HRQOL.