I do this too, my pdoc seems to think its a trait of OCD because I do it every day for several hours at the same time though I do have other symptoms as well such as obsessions and intrusive thoughts. I'm not sure if its a separate issue or not, but I started taking Paxil for it. The first few days were great and I didn't pace at all, now it seems like it wears off everyday around 3pm (I take it at 8 pm) and I get really agitated and restless. Good luck, I hope you find something to help you