I continue to be irritated by the futile ignorance of so many schizophrenia researchers.
"Delusions and hallucinations form as the brain's attempt to account for aberrant salience": this is true, but the emphasis's weird. The aberrant salience causes certain perceptions to emerge into the global workspace with 'apodictic certainty' as a quality, these being delusions (of one kind). Ever heard an unexpected voice on the end of a phone line and known something was wrong, deep in your bones, instantly? It's like that, but for being a wizard, having significance to the world, or being hunted by a mind-dominating cosmic horror whose ignorance of your awareness is the only thing preventing the people around you from uniting to tear you limb from limb (to use examples from someone that's me). I can both 'believe' these things and not think their meaning impinges on the shared world: even while enacting psychotic delusion, were someone to say 'you seem like you're enacting psychotic delusion' I'd agree: that a variety of delusion possesses this character is a significant barrier to meaningful interviewing.
The many theses advanced for how the neurophysiology of schizophrenia produces delusions and hallucinations which don't reference double bookkeeping are actually a better description of manic delusions, in that false beliefs are there produced by a standard-thought-structured reasoning process made unreflective of reality by the altered state rather than possessing the qualitatively distinct character of psychosis qua psychosis. Hallucinations similarly take place in the incommensurable dimension of meaning: unless I'm in some kind of altered state otherwise, it's 'seeing without seeing', not 'the image renders in vision and occludes reality'. Hallucinations also have the feeling of 'necessarily true', but they again don't have to be taken as meaningful in a shared way. Like, this is the shared feature between schizoid personality, schizotypal personality and schizophrenia: you could say the schizoid has the same secondary reality, but it's never expressed enough to explicitly interact with the world outside the person, whereas the other two are more externalized.
Relatedly, decomposing the genetic signal of schizophrenia risk into shared bipolar-and-schizophrenia-risk and only-schizophrenia-risk doesn't quite cut reality at the joints: I expect someone who's mania-affected enough and otherwise impaired enough in functioning to behave incoherently would be diagnosed with schizophrenia, even were they to utterly lack second-book experience: I take SCZ-specific as being an artifact of overall health status interacting with the medical system, not as 'bipolar states aren't reachable by brains impacted by neurodevelopmental failures': it feels like a general 'capacity for state variance' in the non-pathological case and 'inability to constrain state' in the pathological case.
With the schizoaffectivity, I've been deluded for both reasons, and the prior text demonstrates how they differ.
Testimony, for credence: I'm literally a diagnosed schizophrenic, and the last time I was hospitalised my chart said 'barn door mania': I'd also been getting some proper-psychotic delusions and hallucinations beforehand, but I just lied when they asked about those, because getting into 'they feel necessarily true, but I have no belief that they relate to or should be enacted in reality' didn't seem like a productive conversation to have with an admitting psychiatrist, and I was trying to avoid a dangerous-to-me level of restraint. I *was* later helped into becoming comatose (the next day: they failed to treat the diabetes correctly, and insisted I consume massive amounts of carbohydrate with the insulin they were giving me to treat the ketones I came in with, to avoid hypoglycemia, because that'd be dangerous for me. Policy safely shepherded me right into the ICU, guided at every step by the minimisation of liability. Aside from the one nurse who gleefully informed me that she'd fetched a french vanilla yoghurt especially for me, to have with the insulin, or the psychiatrist-and-staff who assaulted me by grabbing my arm from behind, and then used my flinching away as 'assault on a staff member', so they could put me in a higher-control zone: admitting psychiatrist was grinning while this happened, much like how he laughed when an orderly said I'd be in Ward B on entry [because ward B sucked, and defying medical authority means you deserve to suffer. So rude, schizos: luckily, no-one'll believe them if they talk about the abuse you inflict, so you can really work out some tension that way. Perfect victim suffer puppets, just for you. Isn't that why you became a psychiatrist, really? The job descriptions attractive to victim-seekers haven't changed so much, in history]), so this approach did fail, but I continue to believe it was prudent.
(you could maybe combine 'greater variance in state between different regions of one brain instantaneously' with QRI valence theory to explain part of anhedonia and 'pleasure deficit', as greater compressibility of instantaneous state is one of the things there taken as hedonic, and less similarity across areas implies less harmony ceteris paribus).