Alzheimer’s Disease in Adults with Down Syndrome

This clinical review examines the distinctive biological, diagnostic, and management considerations of Down syndrome–associated Alzheimer’s disease (DS-AD). Trisomy 21 and increased expression of the amyloid precursor protein gene contribute to the elevated risk of Alzheimer’s pathology, although clinical onset and progression vary considerably. Symptoms commonly emerge in the fifth or sixth decade and may initially involve changes in behavior, mood, executive functioning, and adaptive skills rather than memory loss. Seizures, particularly late-onset myoclonic epilepsy, are frequent complications and may accompany accelerated cognitive and functional decline. The article emphasizes longitudinal assessment, documentation of changes from established abilities, and evaluation of potentially treatable conditions to avoid diagnostic overshadowing. Although neuroimaging and emerging biomarkers offer important research insights, their clinical diagnostic utility in adults with Down syndrome remains limited. Current pharmacological treatments have uncertain effectiveness, while newer anti-amyloid therapies require further safety and efficacy research in this population. Management priorities include seizure control, health promotion, environmental adaptations, individualized activities, caregiver education, and anticipatory planning. The review underscores the importance of coordinated, person-centered care that addresses progressive neurological changes while maintaining quality of life and supporting family and professional caregivers.

Keller, S.M., Alzheimer’s disease in adults with Down syndrome. Care Down Syndrome, October 2026. (Web pages). https://careds.org/article/alzheimers-disease/