Binge-eating is one of the most common eating disorders. According to a Harvard study, 4% of women and 2% of men have this condition – more than double the number who have anorexia nervosa. Despite its prevalence, it’s often a closet condition where the binge-eater is reluctant to seek help for their problem. Episodes of bingeing are often accompanied by other unhealthy behaviors such as laxatives or purging. What causes this common form of eating disorder? Some researchers have focused in on binge-eating serotonin abnormalities.
Binge-Eating Serotonin Abnormalities: Is There an Association?
Various studies have found abnormalities not only in serotonin but other brain neurotransmitters such as norephinephrine and dopamine. These brain chemicals play an important role in regulating mood and behavior. Alterations in serotonin levels are associated with mood disturbances and depression, but serotonin also affects appetite and impulse control, both of which are altered in binge-eating disorder. It’s not surprising that so much focus has centered on serotonin since people with binge-eating disorder frequently experience depression and anxiety. Depression has been linked to an imbalance in neurotransmitter levels, especially serotonin.
There is some research evidence of a binge-eating serotonin connection. In a study published in Psychopharmacology, investigators used a special technique called single photon emission tomography to look at serotonin transport in the brain in obese women diagnosed with binge-eating disorder. They specifically looked at the activity of serotonin transporter protein. Serotonin transporter protein ferries serotonin into nerve cells in the brain. Altered serotonin transporter activity has been described in disorders such as depression, obsessive-compulsive disorder, and alcoholism.
What did they find? Binge-eating women in this study had decreased serotonin transporter binding to nerve cells in the brain. This is significant since some studies show that increasing serotonin transporter binding reduces binge-eating behavior in people with binge-eating disorder.
Medications That Alter Serotonin Levels Help Some with Binge-Eating Disorder
Another indicator of a binge-eating serotonin connection is the fact that people with binge-eating disorder often improve on anti-depressant medications. As might be expected, anti-depressant medications alter levels of serotonin in the brain.
According to a study published on WebMd, 41% of binge-eaters who took anti-depressants for two months experienced a reduction in binge-eating behavior compared to only 22% taking a placebo pill. Most of the medications they used in this study were serotonin-reuptake inhibitors, also known as SSRIs, which raise serotonin levels in the brain.
Binge-Eating Serotonin Connection: The Bottom Line
There is evidence that serotonin levels are altered in people with binge-eating disorder and that anti-depressants that modify serotonin in the brain improve binge-eating behavior. Still, more research is needed to delve deeper into the complexities of this mysterious disorder.
Biol. Psychiatry. 2007. Feb 1; 61(3): 348-58.
Psychopharmacology. Volume 155, Number 3, 310-314.
Psychopharmacology (Berl). 2003 Oct;170(1):89-93. Epub 2003 May 27.
WebMd. “Antidepressants May Help Control Binge Eating”