Sleep Duration Is Closely Associated with Suicidal Ideation and Suicide Attempt in Korean Adults: A Nationwide Cross-Sectional Study

Introduction: Suicidal ideation and suicide attempts are major risk factors for suicidal death, and sleep problems are associated with an increased risk for mental disorders. We investigated the relationship between sleep duration and suicidal ideation and suicide attempts in a representative sample of the Korean general population from a nationwide survey. Methods: We analyzed data collected from the Korea National Health and Nutrition Examination Survey VI and VII (2013–2018). Suicidal ideation was identified via self-report, and we accessed suicide attempt history. Sleep duration was divided into three categories: short sleep duration (SSD) (≤5 h), normal sleep duration (NSD) (>5 and <9 h), and long sleep duration (LSD) (≥9 h). Sampling weights were applied to obtain estimates for the general Korean population. Results: Overall, 4015 (12.0%), 25,609 (76.5%), and 3857 (11.5%) participants were in the SSD, NSD, and LSD groups, respectively. Among these groups, 7.2%, 2.8%, and 3.3% reported suicidal ideation; while 1.2%, 0.4%, and 0.7% reported a history of suicide attempts. Multiple regression analyses revealed that SSD was significantly more strongly associated with suicidal ideation (adjusted odds ratio (AOR) 1.46, p < 0.001) and attempts (AOR 2.05, p = 0.003) than NSD. No association was found between LSD and suicidal ideation/attempts. Conclusion: Sleep duration is significantly associated with suicidal behavior, and SSD was particularly closely related with an increased risk for suicidal ideation and suicide attempt. Clinicians should carefully consider sleep duration in suicidal patients.