Lexapro is not something you can just take as needed. It takes a few weeks before you feel some results from that. To my knowledge it's not addictive. Klonopin on the other hand can be, and benzodiazepines like that and xanax can be difficult to come off of should you take them regularly for an extended period. I have taken xanax for years as needed, which isn't that often, but has helped me very much in short term situations.