I found it interesting. I used to take care of people with Alzheimer's and did my pediatric nursing rotation in a place for people with developmental disabilities, some with Down's. I am planning to work there when I graduate.
I took care of a woman with Alzheimer's in her home, and got to know her entire extended family (circus), and they had a very strong tendency to dementia and MR, and also alcoholism, depression, ocd..
Always find it interesting how some people just wind up with all those cards and others don't.