In encounters with medical professionals related to my elderly relatives, I was told several times the same kind of anecdotal observation: that "intelligent" pa

In encounters with medical professionals related to my elderly relatives, I was told several times the same kind of anecdotal observation: that "intelligent" patients seem to decline more rapidly with dementia; the hypothesis is that diagnosis is simply delayed with these patients, because their cognitive skills allow them to better cope and mask the early stages of the disease. Then when their coping skills are overwhelmed, the true depth of their impairment gets exposed. I don't think they meant "intelligent" as in IQ test results, but in some observed functional characteristic they would see in geriatric clinical interaction. It makes me wonder if ADHD patients would more often fall on the other side of this functional/coping divide and so get earlier diagnoses. And if so, how could you control for this? Across a population, I would think that delayed detection means lower diagnosis rates since some patients would die before the delayed diagnosis could happen.