I grew up in a town that had what were previously known as "mental asylums" now closed, and as a child, most did, had the notion that to be in there, patients had to be truly mad, not the case, some had suffered trauma, shell shock for example. Depression and anxiety back then I perceive people had to get on with it, I don't imagine there was always a lot of help, I think there was a stigma around anything relating to the mind.
Of late, feeling down, having the blues, most of us do at times, or that kind of low level depression are conditions, where that is what Wes Streeting may have had in mind when he commented that "mental health " per se has been over diagnosed, because the lines have been blurred to lump all of that under the same umbrella. Which doesn't really help those who have clinical depression for example. We live in an age of naval gazing and well known people are forever going on about their mental health sometimes as an excuse for bad behaviour.