I don't think that suicide (logicaly following from "not propagate its genes further") is an actual objective of depression. It is probably more about forcing a

I don't think that suicide (logicaly following from "not propagate its genes further") is an actual objective of depression. It is probably more about forcing an individual to think their problem through - that's what you do when you are depressed, constantly thinking about all the things that went wrong in your life. Thing is, in primitive, savannah environment all problems were simple enough that they could be solved by just few hours/days of thinking and planning. Nowadays we live in civilized society which poses much bigger challenges, which cannot be easily fixed. That's why depression can extend to weeks/months, and after that time it becomes chronic condition, even when the actual problems that caused it has already gone away.