Disney star Demi Lovato is about to fulfill one of her "biggest dreams" -- guest-starring on "Grey's Anatomy."
Demi wrote on her Twitter today: "I'm so thrilled to announce that this week I'm shooting Grey's Anatomy!!!!!!!!" Adding, "By the way... Mr. Patrick Dempsey himself wants me to give a shoutout to you guys! hahahaha so awesome."
According to People, Demi will play a patient being treated for possible schizophrenia.