Sleep issues can be stress related but aren't always (and aren't in my case, at least at this point). Stress does seem to make everything worse though and I could see it playing a role in my family members developing dementia. I could potentially see sleep issues and stress triggering a process. I was thinking more along the lines of circadian issues since the immune system works differently at night so I could imagine that confusion over if it should be in night mode or day mode could potentially cause serious trouble.