Systematic scoping review and ethical analysis of digital health interventions for dementia and cognitive decline

Digital health interventions (DHIs) support people with dementia, mild cognitive impairment (MCI), and subjective cognitive decline (SCD), but evidence and ethical reporting are fragmented. We searched five databases on 9 October 2025 and included 113 studies evaluating DHIs with standardised, objective, or psychometrically validated outcomes. We mapped study designs, populations, intervention focuses, delivery modes, author-reported safeguards, and potential ethical concerns identified through a four-principles-informed framework. VR/AR/MR (49.6%) and robotics (26.5%) were most common; cognitive (34.5%) and physical–cognitive activities (23.0%) predominated. MCI (56.6%) and dementia (54.9%) were frequently represented, whereas SCD appeared in 5.3% of studies. Reported safeguards emphasised physical and psychological safety and data anonymisation; potential concerns included digital literacy, unequal access, consent over time, and emotional attachment. The evidence base was technologically diverse but uneven across populations and ethical domains, identifying priorities for transparent reporting and person-centred DHI design.