Thanks for posting your query.
Its great to find such patients who are so inquisitive and want to be aware of everything. There are various studies weighing the pros and cons of both, both nothing has been conclusive. All i can say is that Celexa is more preferred drug now. Celexa is used for major depressive disorders, with improvements expected in even anxiety disorders. It has also been used in some cases to delay ejaculation.
When it comes only to anxiety, Lexapro is the main drug used for Generalized Anxiety Disorder.
Both of them have similar side effects profile. Lexapro can lead to suicidal thinking in the future, which has been reported in a few cases. However commonly, the side effects are the same.
Hope that answers your query.