Department of Community Mental Health & Law, National Institute of Mental Health, National Center of Neurology and Psychiatry , Kodaira, Tokyo, Japan.
Center for Evolutionary Cognitive Sciences, Graduate School of Arts and Sciences, The University of Tokyo , Meguro-ku, Tokyo, Japan.
Chronobiol Int. 2020 Jun;37(6):877-886. doi: 10.1080/07420528.2020.1746796. Epub 2020 Apr 1.
This study aims to investigate independent associations of habitual sleep durations and sleep timings on weekdays and weekends with depressive symptoms in adolescents who have classes in the morning. We studied grade 7-9 students (942 males and 940 females, aged 12-15 years), who had classes in the morning, at public junior high schools in Japan in a cross-sectional design. The students answered a self-report questionnaire, which covers habitual sleep durations, bedtimes and wake-up times on weekdays and weekends, and depressive symptoms. The Short Mood and Feelings Questionnaire (SMFQ) was used to determine the level of depressive symptoms. The relationship between the variables on sleep habits and the SMFQ score were studied using multivariate linear regression and generalized additive models (GAM), controlling for sex, age and school. Multivariate linear regression analysis revealed that sleep duration on weekdays and relative mid-sleep time on weekdays (i.e. mid-sleep time on weekdays - mid-sleep time on weekends) were independently significantly ( < .001) associated with the SMFQ score. GAM analysis also revealed that sleep duration on weekdays (a reverse J-shaped relationship) and the relative mid-sleep time on weekdays (a negative monotonic/linear relationship) were independently significantly ( < .001) associated with the SMFQ score. These associations were confirmed in both males and females when they were analyzed separately. These results suggest that sleep duration on weekdays and the relative mid-sleep time on weekdays may be independently associated with the level of depressive symptoms in junior high school students who have classes in the morning. These findings may have important implications for the development of novel strategies for preventing mental health problems in adolescents.
本研究旨在调查青少年在有上午课程时的习惯性睡眠时长和睡眠时段（工作日和周末）与抑郁症状之间的独立关联。我们以日本公立初中的 7-9 年级学生（男生 942 名，女生 940 名，年龄 12-15 岁）为对象，采用横断面设计进行研究。学生们回答了一份自我报告问卷，其中涵盖了他们在工作日和周末的习惯性睡眠时长、就寝时间和起床时间，以及抑郁症状。使用短情绪和感受问卷（SMFQ）来确定抑郁症状的水平。使用多元线性回归和广义加性模型（GAM）来研究睡眠习惯变量与 SMFQ 评分之间的关系，同时控制性别、年龄和学校。多元线性回归分析表明，工作日的睡眠时长和工作日的相对中点睡眠时间（即工作日的中点睡眠时间-周末的中点睡眠时间）与 SMFQ 评分独立显著相关（<0.001）。GAM 分析还表明，工作日的睡眠时长（呈反向 J 型关系）和工作日的相对中点睡眠时间（呈负单调/线性关系）与 SMFQ 评分独立显著相关（<0.001）。当分别对男性和女性进行分析时，这些关联得到了证实。这些结果表明，工作日的睡眠时长和工作日的相对中点睡眠时间可能与有上午课程的初中生的抑郁症状水平独立相关。这些发现对于制定预防青少年心理健康问题的新策略可能具有重要意义。
