This inquiry about Dopamine prompted me to do a bit of searching on a few psychology sites. It seems Dopamine's role in the reward-seeking machinery of our brain is pretty much established, and how suffering a deficiency of it could lead to depression & substance abuse --something odd to contemplate a day after we learned of the tragic passing of Philip Seymour Hoffman-- but how Dopamine relates to 'psychosis' & 'schizophrenia' is still a matter of debate. Some people suggest an hyperactivity in certain brain receptors could trigger psychotic episodes, and that's why anti-psychotic medication have "dopamine receptors antagonistic effects."
But the problem here is that these type of 'aberrant' behavior is still being contemplated from a purely chemical --i.e. Materialistic-- perspective. You're hearing voices in your head = there's something wrong with your brain!
I personally don't agree with our society's current take with what we call schizophrenia, because it's a direct result of our collective aversion to what other 'more primitive' cultures would call 'the spiritual realm.' If you live in an Amazonian tribe of hunter-gatherers and you start hearing voices in your head, you're conduced to the tribe elders where you'll be interrogated, they may give you some psychoactive plnts & conduct a ritual ceremony destined to determine what this 'message from the other side' means & how it could affect the life of the tribe. You'd be seen as a valuable member of the group & be respected for being 'chosen by the gods'
If such an episode happens when you're living in the Western world, you're conduced to a psychiatrist who'll start making you all sorts of questions, you'll be pumped with pills & even with electro-shock therapy in more severe cases. You'd be seen as a dysfunctional member of society & be cast aside.
Perhaps is this continual repression of this larger aspect of the human experience, and the fact there aren't adequate outlets to let them be expressed --other than art-- why inevitably the pressure keeps building up, until eventually there's an uncontrollable explosion and this 'other side' manifests abruptly into our everyday life.
Perhaps that's what happens with what we ignorantly call 'the paranormal.'