Pauline - Many of the medications used to treat bipolar disorder unfortunately cause weight gain. As you are aware this becomes an issue that affects compliance with the medication regimen even if it helps with the mood disorder. Topamax has been tauted for its lack of this side effect and it is used as a mood stabilizer. The problem is that it alone may not be able to control your daughter's mood instability and even if it were substituted for the Lamictal, it may not offset the weight gain side effects of Abilify.   As always, good dietary and exercise habits should be encouraged.   Be a strong advocate for your daughter with her psychiatrist so that he/she understands just how troublesome and unacceptable the weight gain is. Urge the doctor to try other combinations of medications that have not been tried to combat this. If you do not get the cooperation that you are looking for consider seeking a consultation from someone who specializes in treatment of mood disorders.   Rick Wirtz   Rick Wirtz is a Psychologist, not a Psychiatrist. Although the majority of Psychologists are not authorized to prescribe medications or give you specific advice about them, they typically have experience working with patients who take a variety of medications. The response above is not intended to diagnose or treat any medical or mental disorder. Any information given in a post about medication is for educational purposes only and primarily to aid you in having an informed discussion with your own physician