Ultimately, humans are quite poorly designed for modern life. Our minds haven't significantly changed since we were chasing herbivores across the savannah. Our bodies never even finished coming down from the trees. The fact we function as a modern society is actually quite impressive.

Depression is likely a bunch of different instincts and survival methods messing each other up. It's likely got ties to hiding. It also likely has got ties to hibernation, along with 101 other minor instincts that can no longer serve their original purpose.

I do know that "learned helplessness" is common to most mammals. Rats can show it, along with depression, when conditions get weird enough. It makes sense as a fall back. Huddle down and save energy until something changes for the better.

One of our biggest advantages is our rational brain. Stopping our own instincts is like trying to stop a goods train. What we can do is be smart. We can reach in and tweak the controls, change the signals. It's hard, particularly with things like depression clouding our thoughts. But it can be done.

I am a ghost in the machine, inside of a bodged together biological computer, piloting a poorly designed meat mech. It's completely absurd, but if I don't take control of it, who the hell will?