Lexapro is marketed to be one of the better SSRI's because it (supposedly) has fewer side effects...I know many people who have taken it and do quite well on it....

It is related to Celexa - chemically, it has the same components but it's structure is the mirror image.

As far as I know it takes four to six weeks to work...It is primarily used for anxiety and depression but as someone else said, OCD is an anxiety disorder...