My mother suffered a nervous breakdown when I was a teen, locking herself in my parents bedroom for 3 months and only speaking to my granny. We were all 'out to get her' and there were people watching the house. As it turned out, she and my father had been going through a rough patch, and she had convinced herself that she needed to lose weight (she was about a 14/16) in order to be able to keep us and be a good mother...I think this goes back to her childhood with said Granny, who is very loving but hyper-critical, especially of my beautiful mother. (?!) She was prescribed slimming pills, and became addicted causing a chemical inbalance. Once this was identified she could be helped, and made a full recovery.
Sadly a few years later she was struck down with a very rare form of cancer resulting in horrendous chemo and eventual leg amputation. She developed very severe depression and family life was a struggle for all of us for years. My father was an absolute rock, but the saddest day was when my mother received a letter from my aunt (father's sister) telling her to stop feeling sorry for herself and pull herself together. Get off her arse and look after her family, stop milking it etc etc. Paraphrased obviously. My father disowned said sister.
My mum's problems are managed now, and she has almost returned to her pre-illness self...albeit with a little more emotional vulnerability. I guess what I am trying to say in a rather prolongued way is that people found dealing with my mother's cancer and near death far more easy than dealing with the fact that she struggled mentally and emotionally after it...which I found odd. If I had been through what she did I would doubt whether I actually wanted to live too.
I do worry about my own mental health at time too. Essentially on the surface I am a very happy, successful and popular person with everything to be happy about. But, and I wouldn't necessarily admit to this in RL, I do have some very dark thoughts at points that I can't dismiss, and I can spend days trying to put certain thoughts, feelings and images out of my mind so I can carry on. My doctor diagnosed my with depression in my early 20ies but I shrugged it off, and now I don't feel I can pursue help again. What have I got to be depressed about? One of my best friends killed herself after a few attempts when we were 19, and despite my protestations to those who know in RL...I can understand why she did it, and I go through those emotions too, I just know I won't act on them. Life scares the living hell out of me, and I know that at some point I will go through pain that I will very much struggle to handle. What is the point in going through that pain when we all just live then die anyway? You get my point. I tend to float through life in some sort of bubble, not really experiencing the highs.
Anyway, I've rambled on enough, probably due to being off work with yet ANOTHER horrendous cold. Back to the OP, I do believe that there is an element of over-diagnoses, and the need to put every behaviour into a box to help us understand it. But this doesn't stop the behaviours existing, or requiring help and support regardless of what we call them.