/sci/ - Science & Math

not even trying to meme here, but what the ever-loving-fuck is the evolutionary purpose of depression? shit just seems like a dead end. i can understand anxiety, keep you on your toes with predators. but depression ruins immune system, makes one practically immobile, etc. why hasn't this been weeded out? how is it so prevalent? is there even any trade-off to it?

At what point in history/prehistory did we begin committing suicide deliberately? Surely gorillas and chimpanzees don't kill themselves to escape the suffering of life. What is the earliest known reference to suicide?