To the Editor: The novel anticonvulsant topiramate is under investigation regarding its mood-stabilizing properties. Topiramate promotes weight loss and effects satiety. It reportedly assists in treating eating disorders, especially binge eating disorder (1, 2). We are aware of only two cases relating topiramate to bulimia nervosa. The first involves the abuse of topiramate for its weight-loss effect (3)—a valid consideration when using this drug with any population. The second case describes topiramate as useful in treating bulimic symptoms in a patient with epilepsy (4). In this case topiramate did not induce significant weight loss but produced cognitive changes in the patient, leading to the cessation of her bulimia.
Ms. A, a 27-year-old professional with a body mass index of 26, was treated with topiramate for bipolar II disorder. After 3 months of taking 75 mg/day, her mood stabilized, and she noticed life-changing differences in her eating disorder. In her teens, Ms. A had struggled with body-image concerns and began purging to lose weight at 18 years of age. She binged and purged from three to 10 times per week, occasionally refraining from this behavior for 3–4 weeks. She tried group therapy and treatment with a selective serotonin reuptake inhibitor with little improvement. When depressed, she binged for comfort and distraction from her negative self-image. When hypomanic, she binged for the "rush" of purging, making her feel powerful. When euthymic, she binged and purged out of boredom.
Ms. A began topiramate therapy when she was bingeing and purging three to four times a week but soon found her eating behavior had returned to normal. Although she lost minimal weight while taking topiramate (2–4 lb), she gained a sense of satiety. She noticed reduced anxiety, minimizing her need to binge for comfort. The most interesting change was in her self-image. She still felt overweight, but it no longer bothered her. She felt better about herself and kept her weight in perspective. Ms. A has been taking topiramate for 7 months and has not binged or purged and reports no desire to do so.
Of the patients described in previous case reports, only the patient with epilepsy and bulimia reported cognitive changes similar to those in our patient, saying she was "less concerned" about her weight (4). Changes in cognition are important in recovery from bulimia nervosa, as evidenced by the success of cognitive behavior therapy. It is unclear why these cognitive changes might occur with topiramate treatment. However, they have been noted in more than one patient and have had dramatic effects on the individuals’ behavior. Therefore, the effect of topiramate on cognition in patients with eating disorders warrants further investigation.