ORPD
stands for Obsessive Robert Pattinson Disorder. A very serious medical condition; symptoms include: extreme sexual arousal upon seeing images of RPattz, constantly checking fansites for information, and having a huge file on your computer dedicated to pictures of RPattz.
ORPD has no cure. The only way to alleviate the symptoms is to express your feelings about RPattz with other ORPD sufferers.