The science has yet to catch up about the mechanisms behind, but there are some truly amazing findings from the last years. It's maybe much more about an immune response because of over excitation of the neurons, excessive oxidative stress etc. than a purely mental thing as many thought and think ...
Look at scholar.google.com or PubMed for things like psychosis immune response, schizophrenia & interleukin-6, NADPH oxidase, glutamate etc... I hope we'll have much better treatments available in some years..
Until then, well.. it's disputed but I'm really against neuroleptics (dopamine antagonists), in my eyes this was the wrong way to go at least for a good part of the people.. they are just causing serious and possibly semi-permanent adverse effects from time to time.. it's not the dopamine that is causing the psychosis.
What helps is more about the general sedation, anti-histaminergic, anti-adrenergic, maybe GABAergic and very probably 5-HT2A antagonistic/inverse agonistic effects (mirtazapine, trazodone are readily available for example). Even some anticonvulsants like pregabalin or gabapentin might be better choices for drug induced psychosis than those nasty toxic neuroleptics!
Blocking dopamine will possibly contribute to these negative symptoms like paranoia, anxiety, feeling detached etc. and certainly hinder the recovery in my eyes.
(Edit: As a side note, ever noticed how many people in psychiatry are chain smoking? That's -part of- because they try to alleviate the dopamine blocking shit.)