Reading through some of those studies (from growing's link) shows that good nutrition obviously has an effect on mood and mood disorders, but it doesn't show (and doesn't claim) that these vitamins are an alternative to prescription drugs. In one of the studies, the participants were taking an average of 2.7 different drugs, and after taking the supplement, their need for drugs decreased by 50%. There is obviously no grounds for claiming that any of the patients were cured!
I guess I am pretty wary of anything that hasn't gone through the FCC. Yes, good nutrition can help stabilize your moods. However, a supplement is probably not the best way to go about getting good nutrition. It is pretty easy (though certainly not as easy as fast food) to eat healthily! I know it helped ME after my psychiatrist suggested that I eat more balanced meals!
“there may be times when we are powerless to prevent injustice,
but there should never be a time when we fail to protest.”
-- Elie Weisel