Association between the number of hours of sleep during weekdays and suicidality among Korean adolescents: Mediating role of depressive and anxiety symptoms

Adolescent suicide is a serious concern worldwide. Sleep problems are a risk factor for suicide. Therefore, the aim of this study was to evaluate associations between sleep duration and suicidal ideation/suicide attempts and determine the extent to which depressive and anxiety symptoms mediate these associations.Data from 54,948 middle and high school students in South Korea were collected by the stratified cluster method through the Korea Youth Risk Behavior Web-based Survey.The weighted prevalences of short and long sleep durations were 19.5 % (95 % confidence interval [CI] = 18.9-20.2) and 4.6 % (95 % CI = 4.3-4.8), respectively. Short sleep duration (<5 h/day) increased the odds of suicidal ideation and suicide attempts by 1.43 (95 % CI = 1.29-1.58) and 1.78 (95 % CI = 1.41-2.25), respectively. Long sleep duration (>9 h/day) increased the odds of suicide attempts by 1.5 (95 % CI = 1.02-2.21). Depressive and anxiety symptoms significantly mediated the relationship between sleep duration and suicidal intensity with a satisfactory goodness of fit.Causal relationships could not be examined due to the cross-sectional study design. Information on other psychopathologies, besides depression and anxiety, was unavailable.Short sleep duration was associated with suicidal ideation and suicide attempts among Korean adolescents. Long sleep duration was associated with suicide attempts only. Both depressive and anxiety symptoms mediated the association between sleep duration and suicidal intensity; therefore, both sleep hour restoration and treatment of depressive/anxiety symptoms should be the goals of suicide prevention strategies.