Schizophrenia is directly linked to dopamine. So is ADHD, but in the opposite way (not enough dopamine). Both were demonstrated on fMRI.
Psychosis is a physical issue in the brain (too much dopamine making the brain fire when it shouldn't) that's solved by administering dopamine antagonists (= antipsychotics).
It's like trying to diagnose and treat a political crisis by observing telephone connections. We see stark changes in telephone use in a crisis. If we meddle with the telephone exchanges we might improve or harm various types of event. It's not really about the telephone calls though, we are just hacking at the messaging of an external event we are ignorant of.
A conspiracy theory induced panic might be superficially "solved" but cutting all the the phone lines. We have not identified or solved the cause though and people don't find life without telephones (dopamine) worth living so they plug them back in (quit their anti-psychotics).
https://news.ycombinator.com/newsguidelines.html