Impact of chronotype, insomnia symptoms, sleep duration, and electronic devices on nonrestorative sleep and daytime sleepiness among Japanese adolescents

Nonrestorative sleep (NRS) and excessive daytime sleepiness (EDS) are important indicators of daytime dysfunction. Electronic media use before bedtime greatly affects adolescent sleep quality. However, few studies have examined factors associated with these symptoms. Therefore, we aimed to investigate the impact of chronotype, electronic device use before bedtime, and insomnia symptoms on NRS and EDS in Japanese adolescents. A web-based cross-sectional survey of 2067 adolescents was conducted in 2022 to mainly assess sleep-related issues (sleep duration, chronotype, insomnia symptoms, NRS, and EDS), time spent using electronic devices, physical activity, and mental health. We analyzed data of 1880 adolescents (age, 16.4 ± 0.8 years; males, 56.7%). NRS and EDS prevalence rates were 54.9% and 39.4%, respectively. In multivariate analysis, evening chronotype [odds ratio (OR): 2.14, 95% confidence interval (CI): 1.58–2.89], difficulty initiating sleep (OR: 1.94, 95% CI: 1.43–2.64), <5 h sleep (OR: 1.77, 95% CI: 1.24–2.54), 5–6 h sleep (OR: 1.52, 95% CI: 1.20–1.93), and using electronic devices just before bedtime (OR: 1.48, 95% CI: 1.08–2.04) were associated with NRS. Evening chronotype (OR: 1.40, 95% CI: 1.07–1.82), early morning awakening (OR: 1.60, 95% CI: 1.02–2.50), using electronic devices just before bedtime (OR: 2.08, 95% CI: 1.48–2.93), and using electronic devices 30 min before bedtime (OR: 1.57, 95% CI: 1.07–2.29) were associated with EDS. Chronotype may be an important factor influencing NRS and EDS. Discontinuing electronic device use at least 30 min before bedtime could benefit affected adolescents.