Gained 50 pounds on Paxil, but it worked sorta. Didn't gain on Lexapro until they recently increased it to 30mg because it isn't working. My theory is, the better a drug works, the worse the side effects -- it means you're metabolizing it well. But everyone is different, some people complain about weight loss on these drugs. They're weird.
People taking SSRIs like Lexapro can complain about weight gain; and there are many that complain about weight loss. Remember, that anxiety can often lead to depression which in itself can cause weight gain for a viarity of reasons. I actually lost weight while taking an SSRI, but I think it had to do a lot more with a normal exercise routine and watching what I ate.
I am taking it 2 months now and haven't gained 1 pound... have you?