 Jennifer Kuiper, CBS News, Chicago. New Harvard study finds some antidepressant drugs make you gain more weight than others. Study of more than 183,000 patients found that at six months, Lexapro, Paxil, and Cymbalta users were 10 to 15 percent more likely to pack it on, at least 5 percent of their starting weight, than people on Zoloft, the most popular antidepressant in the U.S. Deborah Rodriguez, CBS News.