ABSTRACT
Alzheimer's disease (AD) is the commonest form of dementia in older adults with intellectual disability (ID), being particularly associated with Down syndrome (DS). There remain concerns about the accurate diagnosis of DAD in people with ID by neuropsychological means alone. As in the general population, the diagnosis of DAD is mainly obtained by excluding other health disorders which may present as dementia. The diagnostic tests and criteria that are available for the general population are often not applicable to people with ID. Neuropsychological testing in older adults with DS often cannot discriminate between 'normal ageing', mild cognitive impairment and DAD. A better understanding of the biological aspects of AD will improve the longevity of people with DS and will also improve the quality of life for this vulnerable population. DAD is and remains the most formidable medical disorder for older adults with ID.
