Ah yes... A familiar topic. I was on Lexapro (Celexa), Lamictal, Lorezepam for about a year after I was diagnosed BP. While on Lexapro I gained near 30 lbs. (I began the med at 205lbs) I would crave carbohydrates & sweets so I would always be stuffing my face.
In October, I read someplace - I can't remember where though, that a side effect of Lexapro was weight gain and the craving of carbohydrates. So at my next PsyDoc appt, I asked to be switched off of it to another anti-D and was prescribed Wellbutrin.
After a harsh withdrawal from Lexapro (I was taken off of it too fast and had the mother of all manic episodes, delusions and all) and when the Wellbutrin kicked fully in and my cravings went away. In fact, I am rarely hungry and now only eat 3 meals a day, and I cut out the sweets. I don't even crave them anymore either - and I had a really big sweet tooth before starting Lexapro!
I have since been taken off of the Lorazepam and now on Buspar (for about a month now) and I'm happy to say that the craves are still gone and I'm continuing to lose weight. Buspar is really helping better than the Lorazepam for me... I haven't read anywhere about Buspar and weight gain. In fact, it really doesn't have many adverse side effects. (I do get blurred vision from it though...