Good ideas and conversation. No ads, no tracking. Login or Take a Tour!
I would guess that a human's higher cognitive ability plays a significant role. A human's psyche plays a big role in their adaptation to a particular environment. When that cognitive model fails, the person can feel terribly out-of-sync with the world and their prospects can look bleak from this perspective that might have taken significant time and energy to establish. Animals with lesser cognitive abilities needn't cognitively adapt to their surroundings, and thus cannot create such a psychological deficit in the first place.