Joking aside, today I learned what a "culture-bound syndrome" is. That right there is quite substantial evidence that culture is a very real thing, and just because it might be socially constructed doesn't make it any less real (in fact, it might make it more real because it is so widely experienced).
America in 1950 had orders of magnitudes less diagnosed depression than America in 2018, although people had some things that we would label depression today - and that Americans of 2050 will doubtless label something interesting and different.
America in 1950 also had orders of magnitude less access to medical professionals for proper diagnosis.
And,
- The theory was still fairly nascent. "Major depressive disorder" wasn't termed until the 70s.
- Depression and anxiety were much more stigmatized back then. Men were told to "man up".
- Husbands could medicate/institutionalize their wives just because they were "hysterical".
I'd say we had a long way to go back then, and we still have a long way to go.