Health-Related Quality of Life as a Predictor of Major Depressive Episodes in the United States Adult Population: Results from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC)

Objective: To determine the association between health-related quality of life (HRQoL) and onset of major depressive episodes (MDE), and to develop a prediction model to estimate the risk for depression. Methods:  We examined a nationally representative sample of 30,333 adults aged between 18 and 85 years from the National Epidemiologic Survey on Alcohol and Related Conditions, who were free of MDE in the year prior to the Wave 1 (2001-2002) interview, and completed both Wave 1 and Wave 2 (2004-2005) interviews. We fit a logistic regression model to assess the association between HRQoL, measured by the Medical Outcomes Study 12-Item Short-Form Health Survey (SF-12), and onset of MDE between Wave 1 and Wave 2. A point system was developed to estimate the risk for depression. Results: Decreasing Physical Component Summary (PCS) and Mental Component Summary (MCS) scores of SF-12 were associated with increased odds of MDE. A multivariate prediction model for depression based on the PCS and MCS scores, retained age, gender, ethnicity, working status, prior history of MDE, number of other lifetime mental disorders, and number of stressful life events in the past year as predictors. The point system ranges from -4 to 29, and displays good discrimination (c-statistic=0.73, 95%CI: 0.718, 0.739) and calibration (P>0.05). Each point increase represents a 17% increased odds of depression (OR=1.17, 95% CI: 1.16, 1.18; P<0.001). Conclusions: Lower HRQoL is associated with increased risk for MDE. The point system has potential to identify individuals at high risk for MDE, especially in primary care settings.