>Do you really expect that a get-depressed-and-die instinct would reliably result in at least that much benefit to someone's close kin? If not, then you don't really expect such an instinct to evolve by kin selection.
Consider the case of cancer. Cells have builtin functions for commiting suicide when something goes awry, and also do not breed excessively normally. However since knocking those inhibitions out is advantageuos in the short term, cancer arises again and again. The mutations seems to confer an advantage, for the first generation, the second generation... quite a few generations actually. Then suddenly, as the cancer cells reach critical mass, and the parasite/parasitee ratio grows to large, it becomes a huge liability. The cancer cells die. Every single one. The end.
Consider the case of cancer. Cells have builtin functions for commiting suicide when something goes awry, and also do not breed excessively normally. However since knocking those inhibitions out is advantageuos in the short term, cancer arises again and again. The mutations seems to confer an advantage, for the first generation, the second generation... quite a few generations actually. Then suddenly, as the cancer cells reach critical mass, and the parasite/parasitee ratio grows to large, it becomes a huge liability. The cancer cells die. Every single one. The end.