Mass depression in dense populations could be an evolutionary response to over population in an apex species , causing the population to take care of itself to bring things back into balance. amirite?

It's not overpopulation that causes depression, it's stress. If depression is correlated with living in a densely populated area, that's poor civic design, not evolution.

What you see here is a rare specimen that has actually evolved to kill itself.

Said nobody ever until you just now.

Not sure depression has any proven genetic links as of yet, so it's hard for it to be evolutionary rather than just a symptom of better diagnostic work and cataloging compared to previous times in history

I agree that it's a revolutionary response, but rather I can't helpt but think that the problem is that we've moved very far beyond what we've evolved to. The fact that so many of us go to gyms to wear our bodies out and to feel good, is a testament to just how behind our physiques are. Our central nervous systems are still wired to rewards us as if we were ancient. Maybe people get depressed in some part simply because being away from nature, meaningful manual labour, clean air, domesticated animals etc is against our instincts

Huh?!

That's not how evolution works. To propagate, a mutation needs provide an advantage for those that have it, so they reproduce and spread their genes. Severe depression tends to make you not go out at all, and reproduce even less than normal.

Society will be the fall of society