Just let her know you are feeling "blue" and that you would like to go on something. My experience from working in a Doc's office is that at least every 3rd person that comes in is on something. Let her know you are worried about weight gain. If you don't have anxiety issues to begin with I do know the wellbutrin is pretty good, for most. Again, like so many have stated one pill isn't going to be the same for everyone. Heck , my coworker is 120 lbs and takes prozac 80 mgs a day and never gained. I took 20 and put on 40 lbs. So you just never know.
I'm currently taking the wellbutrin. It's trial and error the first mo. I do know i'm not reaching for food all of the time. I rarely get hungry. But I have anxiety and I have to talk to my Doc about that because wellbutrin can make it worse.
Good luck. Remember....not all meds work the same on everyone.
Hugs
Kelly