The Influence of Negative Mental Health on the Health Behavior and the Mortality Risk: Analysis of Korean Longitudinal Study of Aging from 2006 to 2014

Background: Several studies have shown that negative mental health increases risky health behavior and mortality risk. We investigated the relationship between mental health and health behavior, and the causal association between mental health and mortality risk. Methods: We used data from the 8-year (2006-2014) Korean Longitudinal Study of Aging with a cohort of 10,247 individuals (whom we divided into a younger group aged <65 years and an older group aged >= 65 years). Mental health was assessed with the following factors: depression, social engagement, and satisfaction of life. Health behavior was assessed with smoking, alcohol use, and regular exercise. Mortality risk was calculated using survival status and survival months as of 2014. Multiple logistic regression and Cox proportional hazard analysis were performed. Results: Negative mental health was associated with current smoking and sedentary life style, but not with alcohol consumption. In addition, it was associated with an increase in all-cause mortality risk. The increase in mortality risk in the highest quartile (vs. lowest) was 1.71 times (hazard ratio [HR], 1.71; 95% confidence interval [CI], 1.122.62) and 2.07 times (HR, 2.07; 95% CI, 1.60-2.67) for the younger and older group, respectively. Conclusion: Our results show that mental health affects health behavior and mortality risk. A key inference from this study is that improving mental health can lead to positive changes in health behavior and reduce the risk of mortality.