Mother in law (82) has started living in her past, demanding to go home to serve coffee to her dead father-in-law. Any advice?

I forgot to add that, about the UTI. He got them frequently and we could tell by his actions and our reactions and conversations.

Yes. Please check the med levels. My father in law called police several times because people dressed up like Christmas Trees kept showing up. He ended up in a Geratric Psychiatric unit. Once his meds got straightened out he was almost back to himself. That said. If a person is at home and their meds have been checked out and they are doing inappropriate things, it's time. If it's just conversation, go with it.

It is upsetting when this first happens. My cousin was seeing animals in the room, (there were none), a local weatherman came to visit with her, (he did not) and she was shopping with friends at a nearby mall (this last happened in the 1980's.) She just seemed to have a rough weekend. Thereafter, the hallucinations and delusions were not as great. She still believes her doctor sleeps on a couch in her Memory Care Unit and that her roommate is a male friend she had in the 1980's, but she's fine with that. Those things don't upset her, so we go with it.

You do need to check out the meds though. It could be medication or UTI. I'd rule out other causes to be on the safe side.

I would suggest. Having someone review the Medicine she is on. I know! Ambient caused someone I love hallucinate... Seeing & Hearing friends who no-longer were living. Would make Breakfast for Guests at Midnight, pour Oat meal over a Cup of Coffee, pour a Bottle of water on Telephone. Look for Newspaper! at Midnight hour... Thankfully it was the Medicine and they were back to Normal.

Yes, go to youtube and search for Teepa Snow. Here's a link to one to get you started:

Good luck...hugs to you, I can imagine how hard this is for you.

"Oh, mom, they went over to Uncle Bert ' s for a bit. They'll be back in an hour or so. Let's make some biscuits for a surprise"

Watch Teepa Snow ' s videos on dealing with dementia patients. This is so very, very hard. It will pass.