One of my novels involves a young boy who has a mental illness, which one I haven't yet decided.. I'm kind of stuck between some form of schizophrenia and a split personality disorder.. I want it to be recognizable to others that he's 'off', which leads me to another problem.. I'm not sure when these types of mental illness were discovered, and when it became generally recognized/understood by society. I would like to place the story in a time when people wouldn't understand the illness, and therefore be inclined to avoid him whilst remaining as 'modern' as possible. [If it helps the story is set in a small farm town.] So two questions: Any preference as far as the insanity I bestow upon him, and what period of time would be best?