Mental illness doesn't exist? Tell that to a friend of mine who began hearing sounds and voices telling him he was worthless and he better kill himself. I am not speaking figuratively, either - he was not just aware of his own internal thoughts, it was that there were literally voices that seemed to be speaking in his ears telling him this (4 different ones that he heard quite clearly, as well as what he described as a 'background babble' of other voices, plus clicks and whines with no apparent source). Before he actually got help, it progressed to the point where the auditory hallucinations were accompanied by visual ones - for example, he was watching Star Wars, and, in that famous scene in the cantina, Han Solo killed Greedo, but then looked directly at my friend and told him 'pity it wasn't you'.
But no, that was just him having a 'little emotional problem' he wasn't coping with due to being a 'spoiled little first world bitch'.