score:7
On the subject of schizophrenia in history specifically, I happen to be working my way through Julian Jaynes' The Origin of Consciousness in the Breakdown of the Bicameral Mind which I'm finding to be a simply fascinating take on the role of (in)sanity with the origin of civilization. It speaks extensively about schizophrenia and discusses how it was viewed through history.
Essentially, he makes the claim that early on in our civilization the prevalence of schizophrenia may have been higher, and the "voices" were interpreted to be the animal spirits, angels, gods, and ancestors. IOW early on (bronze age) schizophrenia was not insanity, it was normality. He theorizes that a decrease in the prevalence of schizophrenia led to or played into the bronze age collapse. Not sure I buy into it but I'm only a third of the way through the book so far. Regardless it's a fascinatingly different way to look at these topics.
Through the Iron Age up to the Christian Era, schizophrenia would have been treated as perhaps evidence of being touched by the gods, and individuals with these afflictions might be venerated as shamans, priests or oracles and safely sequestered away in temples and shrines. Schizophrenics unfortunately tend to end in suicide at a significantly higher rate than the general population; I must imagine before modern medicines and psychology this would have been even more severe. The madman in the dungeon is a classic trope, and I can easily imagine the more troublesome schizophrenics were handled this way (if not slain outright), but don't know of a source to give you there. I would not be surprised if many were handled as possessed or practitioners of witchcraft, but if this is discussed in the book I haven't gotten to it yet. :-)
It was not really until the 19th century that this received ample study. In fact as a general rule most all psychological diseases were poorly recognized until this point in time.
Anyway, Jaynes' book is quite thick with references and IMHO well worth the read. Despite the obtuse title and hefty theory, it seems to be an easy read and would serve as a good starting point for a study of mental health through history.