Wearables Reveal Early Cognitive Impairment Risk

This systematic review (Jan 2020–Dec 1, 2025) evaluates wearable-derived digital biomarkers for early detection and prevention of cognitive impairment and dementia. It synthesizes 49 studies (median N=145, total >200,000), finding actigraphy-dominant evidence linking disrupted sleep, circadian fragmentation, and activity irregularity to worse cognition; ML/deep-learning models reported AUCs ≈0.70–0.95. The review notes heterogeneity and limited external validation, urging longitudinal prediction studies.