For caregivers who are overwhelmed and puzzled by the actions of their AD relative/friend/whatever, may I suggest reading this article:
Understanding the Dementia Experience
http://www.alzheimercambridge.on.ca/...Experience.pdf
It's a really fascinating look at what is going on inside the heads of dementia patients, and how they view the world.
It's a bit long (in .pdf format so you can download it and print it out), but not in medical-ese. It's very well written, and easily understandable.
I had numerous aha! moments when I first read it.