Background: Eveningness and insomnia are highly comorbid and closely related to psychopathology in adolescents. We aimed to prospectively investigate the trajectories and associations of eveningness and insomnia with daytime functioning, depression and suicidal risk in adolescents.
Methods: A 3-year longitudinal study was conducted among 414 Chinese adolescents. The associations of eveningness and insomnia with daytime functioning, depression and suicidal ideation were analyzed using logistic regressions.
Results: The prevalence rates of eveningness were similar at baseline and follow-up (19.3% vs 22.5%; p = 0.27), while the prevalence of insomnia increased at follow-up (29.2% vs 40.8%; p < 0.001). Among those eveningness adolescents (n=80) at baseline, 46.2% remained as stable evening-type at follow-up, and among those insomnia adolescents (n=121) at baseline, 64.5% had persistent insomnia at follow-up. Logistic regressions showed that stable, incident, and resolved eveningness were associated with excessive daytime sleepiness (EDS) at follow-up, while only persistent and incident insomnia increased the risk of EDS. Persistent and incident insomnia, as well as stable eveningness were independently associated with depression at follow-up. Persistent and incident insomnia, but not eveningness, were associated with suicidal ideation.
Limitations: The outcome assessments were based on self-reported questionnaires and the sample size is modest.
Conclusions: Persistent eveningness and insomnia are significantly associated with greater risks of EDS and depression in adolescents, while both persistent and incident insomnia, but not eveningness, increased the risk of suicidal ideation. These findings underscore the importance of addressing sleep and circadian factors in the management of adolescent mood and daytime functioning.