I note with some amusement that the Wikipedia article solemnly refers to both "Reports of symptoms and health conditions in the media" and "Self-reported cases on the Internet" as major sources of the controversy.

Having said that, the stuff is definitely addictive and definitely messes with MY head (don't know about anybody else's). There's really no conceivable benefit to my consuming it, unless it's attached to the only available caffeine source. (-: