I have been given strange things by drug and party people, surreptitiously, as I came across as being too serious, but the more-stimulating sativa strains (as opposed to drowsier indicas) have helped me to focus, mentally, and feel stronger when I was nauseous. Inflammation and negative emotions are physically-damaging and, within reason, this is therapeutic.
I particularly believe that there is a correlation between Crohn's/Celiac and ASD, see mj as restoring a healthy appetite.
I can see why a heroic, paranoia-inducing dose of sativa would tend to trigger a schizoid person, or far too much indica might trigger a depressive or bipolar person.
Take away all the awe and politicking, and it is knowable, in objective, morally-neutral terms.