As she said - if she had something wrong with her knee, or had given birth, she would have been inundated with support.
Sadly this is true.
Yes, mental illness comes from physical issues in the brain. Those can be there since birth or come later in life.
Mentally illness can be tricky and encompass a lot of different things. In Portugal you can find patients with Down Syndrome (that is a chromosome disorder) in psychiatric hospital. They usually have a building/wards for Down Syndrome.
It is more than challenging to cope with the changes in personality/behaviour, sometimes it is impossible.
Coming from a family with mental illness from both maternal and paternal side, I know that sometimes there is little one can do. The ill person does need to go to hospital or, at least, to have appropriated medication. People with mental illness can become dangerous to themselves and others.
When that happens (and it has happened in my family) it is not possible to have them around. And, sadly, we are not yet capable of solving many of the mental illness issues.
Even if neurologist and neuroscience (unlike many psychiatrist and therapists) look for physical changes in the brain, we still do not know how to cure or mitigate many of the problems.
MLC comes with stress, stress alters the brain. MLC does not seem that difficult to stop/mitigate. Pretty much all it would require would be doctors capable of detecting the early signs and prescribe the right treatment (that does not have to be medicines).
Of course that does not allow for MLC being essentially a developmental issue and the need to be lived through. For it is not the delevolpemt issue that causes the crisis, but stress. The development issue alone would not cause it (people who cannot afford to have MLC can have all the development issues in the world still they do not have a MLC). I also see no need of anyone going through something that could be avoided and that ends up being reduced to being scared/fear.
So, pretty much, yes, I would love some neuroscientist to come up with a way of preventing/mitigate MLC.
Sometimes good things fall apart so better things can fall together. (Marilyn Monroe)