I'm currently 2/3 of the way through a 16 week treatment, and am finding it somewhat helpful but difficult at times. Like blackrose said, it works on finding out 'traps' and behaviours that you get caught in, where they came from and eventually how to deal with the problems. At the start your therapist will ask a lot of questions about your past and make a 'map' of your thought patterns and 'traps' that you get caught in etc. Sorry that this makes very little sense, I would advise you to give it a try though I think that it can be very beneficial. Here is a
link to the main CAT webpage.
please take care, and give it a try feel free to PM me with any specific questions, good luck xx