This is entirely dependent on your individual reaction. For me, neither was much of a factor with any of these things, and most ssris other than possibly Prozac tend to be sedating when they work well, but still, some will get these problems and some won't. These two meds are very similar. Celexa came first, and when the patent ran out, they played with the structure, took some things out, and made Lexapro. Reportedly it has fewer side effects, but who knows if that's really true?