I am sure the hospital called it correctly when they called in psych professionals.
The psych reasons behind it could include EVERYTHING you stated in your post or at least a combination. Only psych professionals could possibly tell BUT that would assume your mom wants to open up with them or if she has just given up.
Sometimes having even a mini stroke creates a fear of a big one happening in people.
So many possible combinations could be causing her issues including even burnout with her kids & the drug issues they have. If she has a physical excuse to not deal with it....it may have become her way of coping.
I went through anorexia several times after 40 years old. Most of the cause was stress & last was a trauma I had to deal with....nothing medically wrong but I got down to very unhealthy weights & required a central line & IV nutrition many times. The cause.....in my case it was the envirinment I was living in