FDA Approved Medication to Reduce Binge Eating and/or Purging

Bulimia nervosa (BN) and binge eating disorder (BED) are serious mental disorders associated with adverse psychological and physical consequences. Treatment options to date offer limited success, leaving at least 50-70% of patients still symptomatic after treatment. The purpose of the study is to evaluate whether phentermine-topiramate (Qsymia), a medication currently FDA approved for the treatment of obesity, will demonstrate efficacy-compared to placebo- when re-purposed for patients with bulimia and binge eating. Participants will be randomized into one of two conditions: qsymia or Placebo. One condition will receive 3 months of phentermine-topiramate, a 2 week washout, then 3 months of placebo. The other condition will receive 3 months of Placebo, a 2 week washout, then 3 months of phentermine-topiramate. Participants will receive a total of 6 months of treatment and then have a 2 month follow-up off of medications.