0963 Sleep Debt and Daytime Sleepiness Mediate the Relationship Between Sleep and Mental Health Outcomes in Young Adults: A Cross-Sectional Study

Abstract

Introduction: Short and long sleep duration and chronotype (i.e., morningness-eveningness) are associated with increased depression and anxiety risk, but differences in individual sleep need and lifestyle may mean these sleep disturbances do not present the same risk across all individuals. This study examined the mediating role of sleep debt and daytime sleepiness in the relationship between sleep disturbances and mental health symptoms in young adults, a population at high risk of both mental health and sleep problems. Methods: Young adult university students (n=2218) and young adults from the general population in the USA (n=992) provided estimates of actual and optimal sleep duration, and completed validated measures of sleepiness (Epworth Sleepiness Scale), chronotype (Horne and östberg morningness-eveningness questionnaire) and depression (Patient Health Questionnaire 2-item scale) and anxiety risk (Generalized Anxiety Disorder 7-item scale). Mediation models examining sleepiness and sleep debt (i.e., difference between optimal and actual sleep) as parallel mediators were tested. Results: Daytime sleepiness and personal sleep debt mediated the relationship between short sleep and depression and anxiety risk in the university sample, while sleepiness mediated these relationships in the general population sample. Sleepiness and sleep debt also mediated the impact of evening-type preferences on depression and anxiety risk in university students, but no mediation of this effect was found in young adults from the general population. Conclusion: This study reports, for the first time, potential mediating mechanisms related to the increased mental health risk conferred by short sleep and evening chronotype. These results have implications for how primary care physicians assess psychopathology risk, arguing for a focus on daytime consequences of sleep disturbances. In university students, assessing daytime sleepiness and personal sleep debt may provide greater insight into anxiety and depression risk, while in the general population these factors may be less important. Thus, tailored screening approaches may be needed to effectively identify anxiety and depression risk among young adults, a particularly vulnerable population.