Wei Li,1,* Na Hu,2,* Xingjie Yang,1,* Wenkai Zheng,3 Jinghui Tong,1 Jiaqi Song,1 Yanying Song,1 Xiaoxiao Gao,1 Zhiren Wang,1 Wenjie Liu,1 Leilei Wang,1 Yunlong Tan,1 Chundi Wang,4 Hu Deng1 

1Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, People’s Republic of China; 2Department of Psychiatry, Beijing Children’s Hospital, Capital Medical University, National Center for Children Healthy, Beijing, People’s Republic of China; 3School of Basic Medicine, Inner Mongolia Medical University, Hohhot, People’s Republic of China; 4Department of Psychology, School of Humanities and Social Sciences, Beihang University, Beijing, People’s Republic of China

*These authors contributed equally to this work

Correspondence: Chundi Wang, Department of Psychology, School of Humanities and Social Sciences, Beihang University, Beijing, People’s Republic of China, Email wangchundi@buaa.edu.cn Hu Deng, Peking University Huilongguan Clinical Medical School, Beijing Huilongguan Hospital, Beijing, 100096, People’s Republic of China, Email denghu501@163.com

Background: Daytime sleepiness is prevalent among Chinese adolescents and has been associated with increased depressive symptoms, impaired cognitive function, and reduced quality of life. However, the interrelationships among these variables remain unclear, particularly regarding whether cognitive function moderates the association between daytime sleepiness and quality of life.
Methods: A large-scale cross-sectional survey was conducted among 52,964 students (grades 7– 12) across five geographically diverse regions of China. Data were collected on daytime sleepiness, depressive symptoms, cognitive dysfunction, and quality of life using standardized self-report measures.
Results: 1) Among the Chinese adolescents, excessive daytime sleepiness (13.87%) and poor quality of life were prevalent. 2) Quality of life was negatively correlated with daytime sleepiness (r = − 0.277), depressive symptoms (r = − 0.416), and cognitive dysfunction (r = − 0.217), all p-values < 0.001. 3) Depressive symptoms played a partially mediating role in the association between daytime sleepiness and quality of life (effect size = − 0.232), accounting for 82.86% of the total effect. 4) In the moderated mediation model of daytime sleepiness → depressive symptoms → quality of life, cognitive dysfunction plays a moderating role. Specifically, cognitive dysfunction significantly moderated the association between daytime sleepiness and depressive symptoms (a = 0.100, SE = 0.003, t = 34.618), the association between depressive symptoms and quality of life (b = − 0.014, SE = 0.005, t = − 2.929), and the direct effect of daytime sleepiness on quality of life (c’ = − 0.048, SE = 0.005, t = − 9.996), all p-values < 0.001.
Conclusion: Depressive symptoms partially mediate the relationship between daytime sleepiness and quality of life, while cognitive dysfunction plays a moderating role in both direct and indirect effects. Improving depressive symptoms and cognitive dysfunction may be potential strategies to mitigate the adverse effects of daytime sleepiness on adolescents’ quality of life.

Keywords: daytime sleepiness, quality of life, cognitive dysfunction, depressive symptoms, adolescents