It generally takes 4-6 weeks for a med to work or not. As to dosage, don't know about that, but higher dosages can bring greater side effects, so that's something to consider. Don't know the ordinary dosage of Celexa, but it sounds like your psychiatrist is dosing it as if it's Lexapro, which is it's newer cousin but uses a lower dose. And don't expect any med to make you anxiety free entirely -- one might, one might not.