I got a warning in the mail today about seroquel. It states that seroquel can cause diabetes or make existing diabetes worse. AstroZeneca knew about this and did not inform either patients or doctors (except in Japan, where they are stricter), and now there is a class-action lawsuit going on. I have been taking seroquel for a couple of years now, and I have diabetes. I need to check with my doctors to determine if the seroquel has made my diabetes worse. This is something you should check with your doctor about if you take this drug.