If I am not mistaking Lexapro is an offshoot of Celexa right?
anti-depressants today are more abundant in regard to variety and how they work. It sometimes takes trying them, working with your pdoc and evaluating what one(s) are best for you.
You do need to give most of them 2-4 weeks before noticing any changes either beneficial or not, then things can be adjusted or changed.
Hang in there, it will happen, it just takes patience.
I wish you lots of luck with this, I've been through this and more, so I can relate quite well

Take care,
"darkeyes"

In giving advice seek to help, not please your friend
SOLON