Ok, this maybe a dumb question, but here it goes. Does anyone know how often Harrisons Principles of Internal Medicine is updated? I have heard every 20 months to 3 years. I'm trying to decide whether to buy one now b/c it could be handy with the case studies we have to do with systems or just wait till right before I go on rotaions. I thought I heard the new edition was coming out next year. I don't want to make the investment now if that is true, especially since I can get it online at school. Anyone know?