I gained 40 pounds when I started mine, but I don't know if it was the antidepressant. I was on Effexor and then Paxil and then Lexapro and now Wellbutrin XL, but at the time that I started on the antidepressants I also started on medicine for my thyroid and birth control pills. I didn't change my eating habits/or excercising though so I don't know. I am actually MORE active now than when I was thin, go figure.