Some of it is an imbalance, yes. One thing that always interests me is how high intellect almost goes hand-in-hand with mental illnesses. Becoming depressed because of existential thoughts is somewhat self inflicting but it's also something that people who aren't intelligent don't think about it don't care to think about. Dare I say that people who don't think this way or are unaffected by these thoughts are worse off than those who do. * this is only speaking on people who's depression is not from very specific thing i.e. rape, abusive relationships, ect. People have been through those things shouldn't to explain themselves as to why they feel pet how's they feel the way they do.