Background Anxiety disorders and insomnia are common modifiable conditions in older adults, but their independent and combined effects on the risk of incident Alzheimer’s disease and related dementias (ADRD) remain unclear. Objectives To estimate the independent and combined associations of anxiety disorders and insomnia with the risk of incident ADRD. Design Retrospective cohort study using an intention-to-treat approach with a 10-year follow-up period (2014–2023). Setting De-identified electronic health record (EHR) data from 70 participating healthcare organizations within the TriNetX Research Network. Participants Adults aged ≥50 years without prior dementia who had regular ambulatory care during a three-year baseline period (n = 1,868,790). Measurements Anxiety and insomnia were identified using ICD-based algorithms and categorized into four exposure groups: neither condition, anxiety only, insomnia only, and both. Incident ADRD was defined by two or more diagnostic codes within 12 months. Entropy balancing controlled for confounding, and weighted Cox proportional hazards models estimated hazard ratios (HRs). Results At baseline, 4.1% had anxiety only, 3.8% had insomnia only, and 1.1% had both. Over follow-up, 2.3% developed ADRD. In weighted models, insomnia alone (HR: 1.12; 95% CI: 1.06–1.19), anxiety alone (HR: 1.49; 95% CI: 1.39–1.60), and co-occurring anxiety and insomnia (HR: 1.31; 95% CI: 1.06–1.62) were each associated with higher ADRD risk compared with neither condition. No significant effect modification by age, sex, or race was observed. Conclusions Anxiety and insomnia independently increase ADRD risk, though insomnia's contribution is very modest compared to the primary association demonstrated by anxiety. Co-occurrence does not confer additional risk beyond anxiety alone. Clinically, routine screening and treatment of anxiety and sleep disturbances represent actionable, broadly applicable strategies for ADRD prevention and healthy cognitive aging.
Ahn et al. (Sat,) studied this question.