What is a "normal state of mind"? One might feel OK, but that doesn't mean that one can't feel even better through improving one's own metabolism. I have a friend who used to be constantly worried, before he tried 5-HTP, a natural serotonine precursor. Shortly after discovering it, he was all like "Gosh, I used to have generalized anxiety disorder!" (which is not entirely accurate due to the diagnostic criteria - but where does disease begin and where does health stop?)