Late use of electronic media and its association with sleep, depression, and suicidality among Korean adolescents

Objective The aim of this study was to investigate the association of adolescents’ last electronic media use time with their sleep and mood disturbances, including depression and suicidality. We also examined whether sleep disturbances and duration mediated the relationship between last media use time and mood disturbances. Methods This cross-sectional, school-based, online survey was administered by the Sleep Center at Samsung Medical Center and the Korea Centers for Disease Control and Prevention (KCDC) in 2011. A total of 26,395 participants (12,593 male and 13,802 female) were recruited from 150 middle and high schools representative of nationwide adolescents from 15 administrative districts in Korea. The sleep habits of participants on weekdays and weekends were evaluated using a questionnaire. Sleep disturbances, depression, and suicidality were assessed using the Korean versions of the Global Sleep Assessment Questionnaire, Epworth Sleepiness Scale, and Beck 19-item Scale for Suicide Ideation. We also collected last media use time, from which we subtracted actual bedtime. Results Late electronic media use was significantly associated with increased mood disturbances including depression and suicidality directly, but not indirectly via sleep duration or disturbances. Conclusion Our results suggest that adolescents might benefit from the restricted use of electronic media after bedtime in terms of their mood and sleep. Moreover, education regarding media use at night might be helpful in preventing youth suicide.