Proxies of Cognitive Reserve and Association With Cognitive Decline and Dementia in Aging Adults With Down Syndrome

ABSTRACT Unquestionably, with the increase in life expectancy, dementia has become a significant health issue in Down syndrome (DS). However, in at least a subset of these individuals, cognitive aging can be considered normal, with absence of dementia symptoms even in the presence of Alzheimer's neuropathology. Therefore, it is essential to understand the complex interactions between risk and protective factors for dementia in this population. Studies are needed to address and elucidate those factors that may improve resilience against cognitive deterioration. Cognitive reserve (CR) is a theoretical construct proposed to explain variability in responses despite similar brain insults. Research addressing CR proxies in people with intellectual disability is limited; evidence is mostly derived from literature reviews or extrapolations from other populations. The present study aims to explore the association between specific proxies of CR and the occurrence of cognitive decline and dementia among adults with DS. Two complementary methodologies were adopted: a retrospective and observational study and a cross‐sectional study involving aging adults with DS. Severe levels of intellectual disability and older age were associated with a higher prevalence of cognitive decline or dementia. We observed a correlation between some proxies of CR. Previous engagement in occupational activities was correlated with regular school attendance, and higher parental education was associated with increased literacy in individuals with Down syndrome. The level of intellectual disability was associated with cognitive decline. Previous engagement in occupational activities and regular school attendance were identified as factors that may be associated with the construct of cognitive reserve and deserve future investigation. Higher parental education was a potential parameter that appears to affect the literacy of their child with trisomy 21.