Is there much research into how schizophrenia/paranoid delusions manifested themselves in past times? I mean they seem to focus around (and be exacerbated by) things that didn't exist that long ago, mainly the internet obviously, but general access to information which allows the brain to formulate bizarre theories involving a wide range of organisations, individuals, religions and histories just wasn't possible until relatively recently. I know William Blake was presumed to be schizophrenic/prone to psychotic episodes on account of his visions, but going back further, to medieval times say, how would a feudal serf have behaved if they had whatever condition Easter Island man here has?