I wonder what the coal mines were like

While I'm sure most of it has always been here, I would be surprised if modern technology hasn't contributed to a spike in depression. I have more content and information than I could ever need in the palm of my hands, and yet everything I read seems to make me hate people.

I don't think I agree with this one. There's so much about lives lived in first world countries, with all the signals and information they are bombarded with, that is almost anti-thetical to our biology. I'm certain we are more mentally unwell than people living simply, especially in the past.

If depression wasn't common someone needs to explain how we have seen so much more of it as fewer people are drinking as much as they had in the past.

Marx's Capital mentions at one point that the working class in Manchester were reliant on drugs like opium to cope with their insane working conditions and poor life/housing conditions.

It's not a new thing at all.