Association between sleep duration, suicidal ideation, and suicidal attempts among Chinese adolescents: The moderating role of depressive symptoms

Background: Suicidal ideation and attempts are still currently serious problems among adolescents worldwide, and there is evidence that sleep problem may be associated with increased rates of mental disorder. This study aimed to examine the associations between sleep duration and suicidal ideation and attempts among adolescents and to test whether depressive symptoms have moderating effects on the associations. Methods: A 3-stage, stratified cluster, random sampling method was used to collect data from 20,130 high school students in southeast China. Results: The weighted prevalence of short sleep among Chinese adolescents was 5.6% (95% CI, 5.3-6.0%), and the weighted prevalence of long sleep was 2.7% (95% CI, 2.5-3.0%). The final results demonstrated that short sleep was positively associated with suicidal ideation (AOR=2.28, 95% CI=1.96-2.66) and suicidal attempts (AOR=3.20, 95% CI=2.46-4.16), and long sleep was only significantly associated with suicidal attempts (AOR=2.47, 95% CI=1.70-3.58). Stratification analyses conducted separately for students with and without depressive symptoms demonstrated that depressive symptoms may have moderating effects on the associations between sleep duration and suicidality. Limitations: Our study sample only included school students, and causal inference could not be examined due to the cross-sectional design. Conclusions: Sleep duration was associated with suicidal ideation and attempts, and the association between sleep duration and suicidal attempts was U-shaped. These findings support that proper treatments services with the potential to restore adolescent normal sleep would be helpful in preventing suicidality among adolescents.