Assessment of cognitive function in individuals with Down syndrome and dementia: a systematic review

ABSTRACT. Individuals with Down syndrome (DS) face a high risk of dementia, particularly Alzheimer’s disease (AD). Early diagnosis is complex due to pre-existing cognitive deficits, underscoring the need for specific diagnostic criteria. Objective: To present cognitive and behavioral features of dementia in DS and examine cognitive assessment tools. Methods: Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, the databases United States National Library of Medicine (PubMed), Scopus, Web of Science, and Virtual Health Library (BVS) were searched for studies (2014-2024) in English, Portuguese, or Spanish. The quality of the included articles was assessed using the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) criteria. Results: Of 254 records screened, 28 studies met the inclusion criteria. Early dementia in DS presents with declines in executive functions, memory, language, attention, and behavioral changes. Behavioral symptoms, including agitation, hallucinations, and apathy, were prominent in AD-DS and prodromal dementia, and may serve as early indicators. Conclusion: Early dementia in individuals with DS is characterized by cognitive and behavioral declines, with behavioral symptoms potentially serving as early diagnostic markers.