I had CBT in addition to medication.
Was it helpful? In a way, yes, in that I realised why my mind was acting, or thinking in a particular way. What it didn't do was stop my mind thinking that way.
I guess the working out why is half the battle, but I had a great deal of difficulty with how that was supposed to make me feel better.
So for example, if I broke my leg...It gets stuck in a cast and the 2 bits of bone knit together again, or if I have a headache, take asprin, and it goes away, but with CBT I couldn't fathom how it was meant to make the problem any better.
That said, I've known other people who it worked really well for, so maybe I just tried to think it through too much!