Celexa didn't cause me to gain weight, but some of the others have, have you tried it? Lexapro is a similar compound of Celexa, kind of like a "cousin" to it.
Just my 2 cents.
I wish you luck, it really sucks when a person either is trying to quit smoking or overcome depression and stuff and then our body rewards us with damn weight gain

Don't give up though, see if your pdoc will try something different or a combo.
I am wishing you hope and luck with this
DE
In giving advice seek to help, not please your friend
SOLON