Alzheimer's disease in Down syndrome and intellectual disability: A review

This paper reviews the literature on Alzheimer's disease (AD) in persons with general intellectual disabilities and those with Down syndrome. It focuses on the prevalence, clinical manifestations, diagnosis and management of AD in these populations. The literature indicates that people with Down syndrome have a greatly increased risk of dementia from their early 40s, while people with general intellectual disabilities have similar rates of AD to the general population. Taking into account the life expectancy of people with intellectual disabilities and those with Down syndrome, guidelines are provided for estimating the proportion of service users in a population that are at risk of developing dementia. The difficulties around diagnosis are reviewed and a particular emphasis is placed on the range of psychometric measures that may contribute to assessment and diagnosis. The management of service users who develop dementia is also reviewed and the implications for service providers are highlighted.