This depends upon the individual.  If you are serious in your desire to work on an issue, and to improve certain aspects of your life, then hypnotherapy can work extremely well. If secondary gain undermines your desire to give up undesirable habits or to otherwise change; and if you are not being entirely honest with yourself, hypnotherapy may not be as effective for you.  You will most likely end up sabotaging yourself and remain unchanged.  Hypnotherapy cannot make you do anything and everything.  You need to bring to the process desire and a willingness to change.