Nonrestorative Sleep is Associated with Somatic and Depressive Symptoms in Japanese Junior High School Students

Study objectives Nonrestorative sleep (NRS) has been identified as a potential risk factor for physical and mental well-being in adults, but limited research exists for children and adolescents. This study aimed to clarify the factors affecting NRS in Japanese junior high school students. Methods The participants were 529 Japanese junior high school students in grades 7 through 9. Participants were asked to respond to Google Forms, and responses were obtained from 392 students. Sleep habits, history of coronavirus disease (COVID-19), physical symptoms, depressive and symptoms, social isolation, insomnia symptoms, and the presence of symptoms of restless legs syndrome (RLS) were identified. NRS was evaluated using the Restorative Sleep Questionnaire, with scores below 48.5 categorizing participants into the NRS group. Logistic regression analysis was conducted to explore the relationship between NRS and various factors, including sleep duration, insomnia symptoms, RLS symptoms, chronotype, and depressive symptoms. Results The NRS group comprised 30.4% of participants and exhibited a higher prevalence of physical and depressive symptoms compared to those with restorative sleep. Logistic regression analysis, adjusted for sex, grade, and COVID-19 history, revealed the following odds ratios (95% confidence intervals) for NRS: depressive symptoms 3.77 (2.24–6.34), evening chronotype 3.00 (1.62–5.56), RLS symptoms 2.75 (1.12–6.76), and insomnia symptoms 1.92 (1.03–3.57). Conclusions These findings suggest that NRS in Japanese junior high school students is associated with physical and mental health issues. When considering health problems in this population, measures are needed to address the sleep-wake problems associated with NRS.