"Is there any medication you take?"
"Nope."
So in an actual case of Dementia-yes he would be taking some sort of medication. But for his disease there is literally no cure-he will be dead within the year. So there's absolutely no point in taking medication. I should also mention because I did more research into this-in his case he doesn't have dementia more memory loss. So I think at a certain point he'd probably realize that Alex's symptoms don't quiteeee line up with that of Dementia