Thanks for the insights, everyone.

My son is 30 years old, passion.

He has repeatedly said that he doesn't feel "safe" at my mother's house, but he never gives a reason. He mentioned having one hallucination when he was lying on the couch and he saw a man with a lawn mower coming to mow him down.

He hasn't asked me to sit with him, though. I've offered, and he accepts. And last night he asked me leave so he could stretch out his legs. (I'm sitting where his feet belong.) He lay there for hours and didn't ask me to come back to the living room which I would have done.

Interestingly, he seemed surprised when I told him he fell asleep within minutes of my joining him on the couch.