Wellbutrin can cause anxiety for people who didn't even have that problem before. When I first went up to 300mg I had terrible irritability. I dropped back down to 150mg and this time when I went back up to 300mg I had no problems at all. It's the only drug that really works for my depression. As far as weight gain--no. Some people lose weight on it because it decreases your appetite. I don't know why your doctor is being so stubborn about not even letting you try it.