they did this 2 years ago…..
schizophrenia is no longer a valid term and is slowly being phased out. new term is dissociation. dissociation pretty much means your amygdala has hijacked your brain and doesn't allow your limbic system to function. then, since your limbic system is shut off, all communications from the other 2 layers of your brain end up being unprocessed aaaaand they end up being the voices a dissociated (schizo) person hears.
this is usually remedied by stimulating the vagal nerve, sending an "all clear" signal to your body and brain, which in turn SHOULD stop the amygdala hijack (usually PTSD) and normal communications with the limbic system begins again.
first hand experience and a lifetime of studying and therapy.