Sleep Disturbance as a Partial Mediator Between Atopic Dermatitis and Depression: A Cross-Sectional Study Based on NHANES

<u><b><i></i></b></u> <u><b><i>Background:</i></b></u> Atopic dermatitis (AD) is a systemic inflammatory disease with notable psychological comorbidities, particularly depression. Sleep disturbance is common in AD and may mediate this relationship, but evidence from population data remains limited.<u><b><i>Objective:</i></b></u> To investigate the association between AD and depression, and evaluate the statistical mediating role of sleep disturbance using a nationally representative sample.<u><b><i>Methods</i></b></u>: Using data from 4177 adults in the 2005-2006 National Health and Nutrition Examination Survey (NHANES). We applied NHANES survey weights and complex sampling design to all analyses. Logistic regression models estimated the association between AD and depression, adjusting for key sociodemographic and lifestyle factors. A nonparametric bootstrap-based mediation analysis (5000 iterations) evaluated the indirect effect through sleep disturbance. Restricted cubic spline (RCS) models assessed potential nonlinear relationships.<u><b><i>Results:</i></b></u> After applying NHANES survey weights, AD was associated with greater odds of depression in the fully adjusted model (adjusted OR = 1.50, 95% confidence interval [CI] = 1.01-2.23, <i>P</i> = 0.048). Sleep disturbance was found to be a significant statistical mediator, accounting for 21.2% (95% CI = 0.024-0.816, <i>P</i> = 0.026) of this total association. RCS models revealed a complex, nonlinear relationship between sleep quality and depression severity.<u><b><i>Conclusion:</i></b></u> In this nationally representative sample, AD is significantly associated with depression. Sleep disturbance statistically accounts for 21.2% of this relationship, suggesting it is an important pathway. These findings suggest that targeting sleep problems may be a valuable strategy to help reduce the psychological burden in AD patients.