Well... in my universe, I'm responsible for looking after my own buckets of mental, emotional, physical and spiritual health. AND that of my partners so... I'm looking out for mine FIRST when seeking partner. I accept there are partner buckets to tend, but I'd want a reasonable load of bucket sizes!
So it is a red flag AND dealbreaker on romancing. OK for friends.
If it comes to pass later on (ex: Alzheimer in older years) that cannot be helped. But going in fresh? No thanks. Friends, please.
My own family medical history has too many mental health issues and I just cannot bear YET ANOTHER person with something ELSE. My own stress/anxiety just cannot take it.
Dad has anosognosia
amid his other stuff. And that's the worst of the lot. The one where he just cannot see that he is sick. It is not denial. The information will not penetrate, ever.
We can tell him, show him things from his file, it just will not go IN. It's like that part of his brain processing center is an empty office and nobody works there. If it were someone like dad dating? His very condition makes it so he just cannot see he'd have a pretty major thing to reveal before getting serious.
I have a lot of compassion for those suffering mental health things but I have to obey my own limit on that one -- I'm just too full already for more people in my life with these complications. Sigh.