The purpose of this study is to evaluate the safety and effectiveness of topiramate compared to placebo in reducing the number of binge days in patients with moderate to severe binge-eating disorder associated with obesity.

Binge-Eating Disorder (BED) is characterized by recurrent binge eating without extreme behaviors to lose weight (e.g., self-induced vomiting, misuse of laxatives) resulting in marked distress, feelings of loss of control, and association with overweight or obesity. Treatment goals for binge-eating therapies include reducing the urge to binge, weight loss, and management of co-existing medical and psychological conditions. Currently, there are no approved medication treatments available for BED, however, studies have shown that treatment for BED (psychotherapy or the use of medications) may be effective at reducing the number of binges, while effects on weight have been variable. Topiramate has been approved for epilepsy in adults and children aged 2 years and above, and for the prevention of migraine in adults. This is a randomized, double-blind, flexible dose, parallel group study to determine if topiramate, a prescription medication approved by the Food & Drug Administration for the treatment of epilepsy and the prevention of migraine, administered at a dose of 400 mg per day or the subject's maximum tolerated dose, is safe and effective compared with placebo in patients with moderate to severe binge-eating disorder associated with obesity. Subjects will have an equal chance of receiving topiramate or placebo. The study hypothesis is that topiramate will be more effective than placebo in reducing the number of binge days per week in patients with moderate to severe binge-eating disorder associated with obesity and is generally well tolerated. Patients completing the 16-week double-blind phase of the trial are eligible to participate in the 12-week open-label phase of the study.

Topiramate tablets (25 and/or 100 mg) or placebo in increasing doses starting at 25 mg/day up to 400 mg/ day (or MTD) during first 8 wks, achieved dose maintained for additional 8 wks. If entering OL reduce DB medication while increasing dose of active topiramate to 400mg/day or MTD for addn 12 wks.

Inclusion Criteria:

• Diagnosis of binge-eating disorder
• 3 or more binge days per week in the 2 weeks prior to baseline
• Obese (body mass index >=30 and <=50 kilograms per square meter)
• Uncomplicated/controlled Type II diabetes or hypertension are acceptable
• In generally good health
• If female capable of having children, using acceptable method of birth control

Exclusion Criteria:

• No current or past history of schizophrenia, other psychotic disorder, or bipolar disorder
• Significant depression that requires treatment with medication or therapy
• At risk to self or others
• No current or recent (within 3 months) diagnosis of abusing drugs or alcohol
• Initiation of formal psychiatric therapy in past 6 months for binge-eating disorder or any other psychiatric disorder
• Pregnant or breast-feeding
• No clinically significant medical condition