Abstract
BACKGROUND: Sleep disturbances are a known risk factor for alcohol use, yet their long-term predictive value for alcohol use disorder (AUD)-especially in the context of co-occurring anxiety symptoms-remains understudied. The present study thus applied machine learning with internal validation to evaluate how sleep disturbances predict nine-year AUD symptoms in midlife adults. It also introduces the Sleep-Anxiety Dysregulation Model of AUD Risk, which posits that sleep and anxiety symptoms confer shared vulnerability via disrupted arousal regulation. METHOD: Community-dwelling midlife adults (N = 1,054) completed clinical interviews, self-reports, and a seven-day actigraphy protocol to assess demographics, psychiatric symptoms, anxiety severity, subjective sleep, and objective actigraphy sleep indices. A five-fold nested cross-validated random forest identified potentially nonlinear and interactive predictors. The baseline model included 41 variables. RESULTS: The final multivariable model explained over two-fifths of the variance in nine-year AUD symptoms (R(2) = 42.7%, 95% confidence intervals [40.1%-45.8%]). Key baseline predictors of nine-year AUD severity included lower rest-stage activity, sleep discontinuity and fragmentation patterns, and decreased active wake-stage physical movement. Other baseline predictors comprised younger age, higher generalized anxiety disorder, major depression, and panic disorder severity. No subjective sleep disturbances predicted nine-year AUD symptoms. CONCLUSIONS: Results underscore the shared contribution of sleep and anxiety disturbances to long-term AUD risk. The proposed Sleep-Anxiety Dysregulation Model of AUD Risk offers an integrative framework suggesting that AUD symptoms may emerge via chronic arousal dysregulation, including heightened physiological reactivity. Externally validating this model may inform preventive strategies targeting distal risk processes underlying AUD.