Yes, I was very afraid to admit to myself the reality of my situation with my ex and it took me some time to get there. I also think that some people's partners are in crisis and will come out of it. I think my ex partner has come out of his current crisis and has moved on. I do believe it will happen again though. There'll be another crisis along the way.
I do think in some instances you need a label. For me, if my ex was Bi-polar, it means that there's a chance my kids could develop this. I see elements of my son in the things that my ex used to say or do and I worry for him. As it turns out, the term was banded about, some 8 years ago, but as my ex stopped seeing the psychiatrist it was never confirmed. I also hear varying stories about whether it is hereditary. My counsellor tells me that it isn't hereditary. Ultimately though, I have put it to the back of my mind.
I use tactics here to help me deal with my ex as we have kids, but if we didn't he would be a complete vanisher and I wouldn't be even thinking about terms for what he is as he'd be out of my life completely. I do sometimes really wish this was the case.
I have to work on myself to understand why I was attracted to someone like my ex. I was an enabler to his behaviour and am definitely an empath. We had similar Foo issues with our family background and it manifested in us in different ways.
I just hope I pick a little more wisely for the partner in my next relationship.