First off, let me try to explain the difference between celexa (citalopram), and lexapro (escitalopram), since they are very similar.
Note: celexa is on the left, and lexapro is on the right.
Celexa is the older drug that has lost its patent in the last few years. Lexapro, is the 'new and improved' version of celexa, which consists of only the S (left) isomer escitalopram, whereas celexa is a 'dirtier' drug, consisting of both the S (left) and R (right) isomers. Celexa eventually gets converted into lexapro in the body.
Or, if you prefer, wikipedia's technical explanation: "Citalopram is sold as a racemic mixture, consisting of 50% R-(−)-citalopram and 50% S-(+)-citalopram. Only the S-(+) enantiomer has the desired antidepressant effect. Lundbeck now markets the S-(+) enantiomer, the generic name of which is escitalopram. Whereas citalopram is supplied as the hydrobromide, escitalopram is sold as the oxalate salt. The salt form makes these otherwise lipophilic compounds watersoluble."
What's puzzling to the researchers about this study is that while celexa was shown to be helpful in treating compulsive shopping, lexapro was not.
I'd like to leave it at that, and say that celexa and lexapro really are different, as many of us have observed in patients who have been on both. People often do like one better than the other (totally depends on the individual).
Thankfully, the article below does actually analzye both studies, and it appears that both studies have design flaws, most glaringly of which is their small sample sizes (24 pts in the celexa study in 2003, 17 lexapro and 9 controls in the newer study).