Ann, my cat sitter, shared this sad story: her great niece, after they all spent Christmas together as a big extended family, hanged herself in her bedroom at home. She had been receiving counseling for months. She had wonderful parents. She herself said once: "I have wonderful parents and I love my school, I just do not know why I am so unhappy all the time". Sounds like a completely endogenous depression without anything situational. Horrible.