That's an interesting question. prozac stopped the voices in my head, but that was like ten years ago (i am still on it), but I gotta say, I haven't complained about having a song stuck in my head for a long long time, but I sure used to. and especially when i'm doing something rhythmic like walking, I will start singing something stupid like 'by the sea, by the sea'. I would vote for it being OCD, as prozac is used against OCD.