Cognitive Behavioral Therapy is a relatively short-term, goal-oriented form of psych- therapy. Depending on the problem and the intensity of symptoms, (e.g. depression, anxiety, panic attacks), you can expect improvement after 16 weekly sessions, or less, of CBT. Of course, this depends on other variables.
How long have you suffered from the problem and how severe are your symptoms? Are there environmental factors contributing to your problem, such as job stress or marital conflict? How motivated are you to practice new skills between therapy sessions? Most likely you didn’t acquire this problem overnight, and getting relief may take a while.
If your symptoms are severe, I recommend coming to therapy on a weekly basis for a couple of months. Once you have learned some methods to manage your symptoms, we can decrease the frequency of sessions to every other week as you continue to make progress toward your goals