The network linking daytime sleepiness, chronotype, and emotional distress is bridged by anxiety and depression in young adults

Emotional disturbances such as anxiety and depression are increasingly recognized to be closely associated with individual chronotype and levels of daytime sleepiness. A growing body of research is now exploring the complex interplay between daytime sleepiness, circadian rhythms, and emotional disturbances from diverse methodological and theoretical perspectives. Building on this foundation, the present study employed network analysis to examine the associations among chronotype, daytime sleepiness, and emotional disturbances. A total of 559 young adults (224 males, 335 females; mean age = 21.14 years) were recruited and completed the Morningness-Eveningness Questionnaire-Self-Assessment version (MEQ-SA), the Epworth Sleepiness Scale (ESS), and the Depression Anxiety Stress Scale (DASS-21). Descriptive analyses indicated that individuals who took longer and earlier naps tended to exhibit more evening-oriented chronotypes. Network analysis revealed three stable network structures, with anxiety and depressive symptoms serving as bridging nodes that connect the dimensions of daytime sleepiness, chronotype, and emotional disturbances. Across the three networks, shared core symptoms included "restlessness," "depression," and "anxiety," with "restlessness" and "depression" playing pivotal roles in inter-symptom connectivity. These findings suggest that both chronotype and daytime sleepiness are highly associated with emotional symptoms. Future interventions targeting emotional disorders may benefit from simultaneously addressing both factors to enhance treatment efficacy. Additionally, attention should be given to the role of social and environmental factors in shaping emotional well-being.