Interesting, yet possibly useless fact time! I read an article once, where a doctor put forward the theory that when people with schizophrenia have auditory or visual hallucinations, it's actually their brains compensating for the fact that they don't dream. Apparently, the REM state is a precursor to dreaming, yet the two are actually separate - you have to be in the REM state to dream, but you don't neccessarily dream when you're in REM sleep. Anyway, his theory was that schizophrenic hallucinations are caused by the brain being 'trapped' in the REM state, which means that they are awake, but their brain is dreaming, which causes their dreams to seemingly manifest as reality.
Like I said, it's all very interesting, but probably not that useful to you in the long run - yay for sharing, though!