I read some where once where you could divide schizophrenics up into 3 groups. 1st group might only have one psychotic break and then not suffer any other and be OK with out meds. 2nd group will find the right meds and function fairly normally by continuing to take the meds. 3rd group may still have a difficult time even with the meds.
As far as John Nash goes, I heard him say once that he thought that he might have slowly gotten better because his hormone levels started to lessen as he grew older.
Most people first start to notice psychotic episodes when their reproductive hormone levels are fairly high. I see a definite connection there.