Memantine (Namenda) is approved to treat Alzheimer’s disease, but may also be effective in treating binge eating disorder. A new study published in the International Journal of Eating Disorders demonstrates memantine’s effectiveness in a small group of patients with binge eating disorder.

Binge eating is a relatively newly recognized psychiatric disorder that involves recurrent episodes of binge eating without extreme behaviors to lose weight. Binge eating is the most common eating disorder, affecting up to 3% of American adults. It is most often seen in people aged 46 to 55 years. Binge eating is typically characterized by eating unusually large amounts of food, and most people with this disorder feel their eating is out of control. They may also eat more quickly than normal during binge episodes, eat until they are uncomfortably full, eat large amounts of food when they not hungry, eat alone to avoid embarrassment, and feel guilty, disgusted, or depressed after eating.

The current study involved 16 participants with binge eating disorder, 15 of whom completed at least one follow-up session, and 9 of whom completed the entire study. This was an open-label, 12-week trial to assess the efficacy of memantine in binge eating disorder. The individuals received a flexible dose of memantine, ranging from 5 to 20 mg daily. (The normal daily dose of memantine in the treatment of Alzheimer’s disease is 20 mg daily.) The primary outcome was frequency of binge eating days. Secondarily, the researchers evaluated the frequency of binge episodes, body mass index (BMI), weight, Clinical Global Impressions Severity (CGI-S), Three Factor Eating Questionnaire (TFEQ), Montgomery-Asberg Depression Rating Scale (MADRS), Hamilton Anxiety Rating Scale (HAM-A), and Sheehan Disability Scale (SDS).

Memantine significantly reduced the frequency of binge days and binge episodes, as well as severity of illness, disinhibition as measured by the TEFQ, and disability measured on the SDS. The number of binge days per week decreased from 4.4 to 1.1, and the number of binge episodes per week decreased from 5.5 to 1.2. There was no significant change in BMI, body weight, depression, or anxiety. Memantine was well tolerated by the participants.

The small patient population, short study duration, and lack of a placebo-controlled group limit the application of the results. Still, the results are the latest in a series of similar promising results in both animal and human models.

Recent data has pointed to a dysfunction in the activity of the neurotransmitter glutamate in mood disorders, anxiety disorders, obsessive-compulsive disorders, and schizophrenia. Memantine acts as an antagonist at the N-methyl-d-aspartate glutamate receptor, and has been used off-label for various psychiatric disorders, with encouraging results. However, without large, controlled, clinical trials, the routine use of memantine for such disorders is not recommended. The researchers that conducted the current study are planning large, placebo-controlled studies to assess the effectiveness of memantine in eating disorders.

References

A BISAGA, W DANYSZ, R FOLTIN (2008). Antagonism of glutamatergic NMDA and mGluR5 receptors decreases consumption of food in baboon model of binge-eating disorder European Neuropsychopharmacology, 18 (11), 794-802 DOI: 10.1016/j.euroneuro.2008.05.004

Brian P. Brennan, Jacqueline L. Roberts, Kate V. Fogarty, Karina A. Reynolds, Jeffrey M. Jonas, James I. Hudson (2008). Memantine in the treatment of binge eating disorder: An open-label, prospective trial International Journal of Eating Disorders, 41 (6), 520-526 DOI: 10.1002/eat.20541

Zdanys K, Tampi RR (2008). A systematic review of off-label uses of memantine for psychiatric disorders. Prog Neuropsychopharmacol Biol Psychiatry, 32 (6), 1362-1374 PMID: 18262702