My point is that there does not seem to be any evolutionary advantage to psychosis, at least not presently in Western culture. Although, as I mentioned, there may be a fight/flight component (e.g. a psychotic break may very well stem from an individuals mental/emotional/physical imbalance, and in a way help to reorient them and their support system so that they can regain health). In other cultures, psychotic individuals are sometimes revered and held in very high esteem... those cultures don't view the psychotic individual as "mentally ill" or defective, nor do they try to "fix" them with heavy duty medication regimens and psych hospitals (both of which likely exacerbate or prolong psychotic symptomatology).
I didn't claim that trauma automatically leads to psychosis or that psychosis stems solely from trauma, just that there is a close association between the two according to our knowledge at this time. I believe the literature shows a closer association between psychosis and trauma than any of the other factors you mentioned (outside of clearly biologically based factors- e.g. tumors, drugs, sleep, etc).
Of note, your article mentions what may very well have been a traumatic situation, namely being a friggin child genius in an environment not supportive of the same. Basically, his mental needs were neglected... and in the case where you have a next level genius we should not discount the potential impact.
"His only mild complaint was that his childhood home in the Appalachians was not a very intellectual place, and he had to become an avid reader to learn what could not be taught in his own community. This hardly seems like the type of childhood trauma that some researchers associate with later schizophrenic episodes."
Now I'm not making any hard claims that he was traumatized (that is a very individual thing and different for virtually everybody) and I agree that trauma is not necessary for a person to experience psychosis... Here I'm mainly playing devils advocate, and if there is one thing I've learned it's that people can be traumatized by all sorts of things.
Here is an excerpt from an article supporting a trauma/psychosis association:
"They have examined hundreds of published academic papers using meta-analysis—a statistical technique for aggregating the results over many studies—and what they have concluded is that ‘social inequality and racial
discrimination drives people crazy'... Other early traumas in life, such as
child sexual abuse, physical abuse and
bullying, increase the risk of psychosis, Professor Bentall explained. Their results show that, those who are traumatized in early life are three times at greater risk of becoming
psychotic in adult life... And in another study it was found that those who had experienced
childhood sexual abuse were ten times at greater risk of having
hallucinations... This new work builds on research over the past decade by Professor Bentall and others such as Professors John Read and Mark Shevlin which has also begun to illuminate the links between early abuse, trauma and psychosis... Professor Bentall cautioned that while early trauma increased the risk of psychosis, not everyone who has had early trauma will develop psychosis, and importantly, not everyone who has psychotic experiences has experienced childhood abuse."
https://www.psychologytoday.com/us/blog/what-doesnt-kill-us/201111/trauma-and-psychosis
I pretty much agree with everything you wrote here, although I'd caution against the science supporting supposed psychiatric drug efficacy... As you mentioned, we can generally sedate the psychosis away, however, the use of these medications too often comes at a very hefty price.
Interestingly enough, there are other countries who do very well treating psychosis without medications, and these folks argue largely against any use of psychotropic medications as they believe it interferes with the natural processes necessary for symptom resolution (which goes back to a possible evolutionary benefit as noted above).