Effect of physical activity on suicidal ideation differs by gender and activity level

Background: Suicide is a critical complication of psychiatric disorders. Physical activity has a positive effect on mental health; however, its effects on suicidal ideation have received little attention compared to other psychiatric symptoms. Methods: Data were obtained from the Korea National Health and Nutrition Examination Survey 2014. Suicidal ideation was measured by the ninth item of the Patient Health Questionnaire-9. Physical activity was measured by the International Physical Activity Questionnaire (IPAQ) and categorized into three groups by activity level. Multiple logistic regression analysis was performed for the entire sample, men, and women. The following three models were used: Model 1 (adjusted for sociodemographic and health-related variables), Model 2 (additionally adjusted for subjective body image), and Model 3 (additionally adjusted for diagnosed depression). Results: Compared to the low IPAQ group, the moderate IPAQ group was significantly associated with decreased suicidal ideation in Model 3 for the entire sample (OR, 0.733; 95% CI, 0.538–0.999) and in all models for women. However, the high IPAQ group showed no significant association. None of the IPAQ groups showed significant associations in men. Limitations: This is a cross-sectional study. Therefore, the direction of causality cannot be determined. This study also investigated suicidal ideation over the past two weeks, which may be inconsistent with studies conducted over the past year. Conclusions: The beneficial relationship between physical activity and suicidal ideation is weaker in men and individuals with high activity levels. Detailed guidelines on physical activity according to gender and activity level are recommended.