Lifestyle factors and suicide risk: A nationwide population-based study

Objective: To examine the association between lifestyle factors and suicide-related outcomes. Methods: Data from the Korea National Health and Nutrition Examination Survey in 2015 and 2017 were used. We identified lifestyle factors including smoking, physical activity, alcohol intake, and the Healthy Eating Index (HEI) in 9529 eligible subjects. We analyzed the risk of suicidal ideation, plan, attempt, and the composite of suicidality within the past year according to the lifestyle factors. In addition, stratified analyses were performed according to the diagnostic history of depression. Results: Compared to never-smokers, ex-smokers and current smokers showed an increased risk of suicidal ideation, suicidal plan, and the composite of suicidality. Compared to the low HEI group, those with the highest HEI showed a decreased risk of suicide ideation and the composite of suicidality. Among those with depression, the increased risk of suicide-related outcomes from smoking was more prominent and heavy drinking was associated with an increased risk of suicide attempts. Conclusion: Smoking and heavy drinking were associated with an increased risk of suicide-related outcomes, but high-quality diets and non-heavy drinking were associated with a decreased risk. In people with depression, the associations between lifestyle factors and suicide-related outcomes were stronger than in those without depression.