http://www.tvline.com/2012/01/matts-inside-line-scoop-criminal-minds-fringe-bones-castle-revenge/
"Criminal Minds | At long last, I may have an answer to one of this CBS dramas most puzzling mysteries: What happened with Reids conspicuous Season 6 headaches? The answer: Blame Sue Sylvester! The hope, series boss Erica Messer tells me, was that we were going to be able to explore those headaches a bit last year with Jane Lynch (as Reids mother), and get her take on it. But because of Janes schedule, we just were never able to. While Messer cops to setting up a story that hasnt (yet) paid off, she notes, Its still a part of the character, and that its a sort of psychosomatic issue he has speaks volumes. Turning to what is ahead for Reid, Messer cites this seasons 11th episode, [TONIGHT!] where Matthew Gray Gublers alter ego reflects on whether hes fulfilling his potential. [Being so smart] at 14 youre really, really special, because not everybody could do what you do. But at 30, it doesnt feel like youre as special as you once were.