Adults with Down syndrome and early stage Alzheimer's disease showed decline in their ability to selectively attend to stimuli in a multitrial cancellation task. They also showed variability in their performance over the test trials, whereas healthy participants showed stability. These changes in performance were observed approximately 2 years…

The authors present a case study of a 70-year-old man with Down syndrome ("Mr. C.") who they followed for 16 years and who does not exhibit declines in cognitive or functional capacities indicative of dementia, despite having well-documented, complete trisomy 21. The authors describe the age-associated changes that occurred over 16 years as well…

Rates of dementia in adults with mental retardation without Down syndrome were equivalent to or lower than would be expected compared to general population rates, whereas prevalence rates of other chronic health concerns varied as a function of condition. Given that individual differences in vulnerability to Alzheimer's disease have been…