I think you are right that these things were less common 50 or a 100 years ago, but consider this (first comment on the blog)

"It’s not a job that I want, or that I even feel really suited for, and it’s not paying what I need, but after 11 months of unemployment, you take what you can get. I’m not going to spill all my guts here, but life is really starting to suck for me, mostly because I’m shoulder-deep in debt and can’t see a way to scrabble myself back up. This is an important fact because with how little I make, and how much I owe, I no longer can afford health insurance."

How common was this situation 50 or 100 years ago? And 100 years ago people would have had better support systems from living in smaller communities. Modern life causes depression; I don't think it's necessarily an over diagnosis.