Early developmental exposure to two different antidepressants, Prozac and Lexapro, has been studied by researchers in a mouse model that mimics human third trimester medication exposure. They found that, although these serotonin-selective reuptake inhibiting antidepressants were thought to work the same way, they did not produce the same long-term changes in anxiety behavior in the adult mice. About 15 percent of women in the United States suffer from anxiety disorders and depression during their pregnancies, and many are prescribed antidepressants.