So Prozac got approval for depression, but was always used for anxiety as well.
Zoloft came next,
and got approval for depression as well, but was also always used for anxiety. Paxil came next, and got approved for both depression and panic disorder, but has always been used for all types of anxiety. Then Luvox, which chose OCD as its "special" benefit. And so on. So while Celexa wasn't approved specifically for anxiety conditions, Lexapro, the newest model of Celexa, was.