… as the world becomes even more random and confusing, the brain very slowly adjusts its highest level parameters. It concludes, on a level much deeper than consciousness, that the world does not make sense, that it’s not really useful to act because it’s impossible to predict the consequences of actions, and that it’s not worth drawing on prior knowledge because anything could happen at any time. It gets a sort of learned helplessness about cognition, where since it never works it’s not even worth trying. The onslaught of random evidence slowly twists the highest-level beliefs into whatever form best explains random evidence (usually: that there’s a conspiracy to do random things), and twists the fundamental parameters into a form where they expect evidence to be mostly random and aren’t going to really care about it one way or the other.
Antipsychotics treat the positive symptoms of schizophrenia – the hallucinations and delusions – pretty well. But they don’t treat the negative symptoms much at all (except, of course, clozapine). Plausibly, their antidopaminergic effect prevents the spikes of aberrant prediction error, so that the onslaught of weird coincidences stops and things only seem about as relevant as they really are.
But if your brain has already spent years twisting itself into a shape determined by random coincidences, antipsychotics aren’t going to do anything for that. It’s not even obvious that a few years of evidence working normally will twist it back; if your brain has adopted the hyperprior of “evidence never works, stop trying to respond to it”, it’s hard to see how evidence could convince it otherwise.
— Slate Star Codex, “Treating The Prodrome“