The contribution of sleep to anorexia nervosa severity

Purpose: Anorexia nervosa (AN) is associated with poor sleep and altered circadian rhythms. Evidence is unclear as to whether these features relate to ongoing psychiatric symptoms of AN, or are merely concomitant with low weight. In this study, we sought to evaluate subjective sleep quality and sleep–wake preferences in a sample of individuals with lifetime AN. Furthermore, we aimed to examine whether sleep quality would significantly predict AN symptom severity, after accounting for demographic features and negative emotions (depression, anxiety and stress). Methods: Adults with a lifetime diagnosis of AN (n= 96) or no lifetime psychiatric diagnoses (NC; n= 246) completed an online survey assessing demographics, sleep quality, circadian sleep–wake preferences, eating disorder symptoms, and negative emotions. Results: AN participants reported significantly poorer sleep quality overall, including increased sleep disturbances, use of sleep medications, and daytime dysfunction, as compared to NC participants. Groups did not differ significantly in circadian sleep–wake preferences. Regression analysis showed that among AN participants, sleep quality and negative emotions significantly predicted AN symptom severity, while sex and body mass index (BMI) did not. Conclusion: The findings demonstrate that poor sleep quality was associated with more severe symptoms of AN, even when accounting for negative emotions and BMI. Future research should investigate causal interactions between sleep quality and AN symptom severity longitudinally and across different recovery stages. Level of evidence: Level III—Cohort and case–control analytic studies.