The reasons people are depressed are very complicated I think. For me personally it IS a combination of high expectations and a million other things. I get the best out of people, and the worst out of myself. People who don't know me would never expect I am suicidal. I think even in my happiest, most elated moments, if a genie asked me if I wish to have never existed, I would say yes. I would say im a pretty classic ENTJ and it makes my depression very confusing. The best way I could describe it is apathetic. I did CBT with a therapist when I was younger, and part of it was learning to control negative self talk, I filled out hundreds of these sheets with examples of thoughts I would have about myself through the day. He said he had never seen so many before. I am extremely aware of the self inflicted nature of my depression and suicidal thoughts, but I cant help it. When I was happy, I was less productive. I know it seems counter intuitive but this is the worst I have ever felt and I have never been so consistent at the gym, or on top of my studies, or reading more books. I have a pact with myself that if I stop improving or at least trying to get better, then ill kill myself. This kind of turned into a rant and I don't even know if it answered your question lol, but thanks for reading! I'm happy to answer any questions, talking about suicide/depression for me is like talking about the weather, I don't really "open up" I'm an open book from the start.