New research suggests that a brain malfunction that leads to deficits in endocannabinoids may contribute to anorexia nervosa and bulimia.
Endocannabinoids are substances made by the brain that affect brain function and chemistry in ways that resemble the effects of cannabis derivatives, including marijuana and hashish.
These drugs are often used recreationally and are well known to influence appetite, i.e. causing hunger or the “munchies.”
Accordingly, deficits in this brain system would logically be associated with reduced appetite.
In the study reported in Biological Psychiatry, researchers measured the status of the endocannabinoid system indirectly by determining whether there was an increase or decrease in the density of endocannabinoid receptors, called the CB1 receptor.
They used positron emission tomography, or PET, imaging to study several brain regions. Then, they compared these densities in women with anorexia or bulimia with those of healthy women.
Upon analysis, researchers found evidence of deficits in endocannabinoid levels or reduced CB1 receptor function in the brains of women with anorexia nervosa. CB1R availability was also increased in the brain region called the insula in both anorexia and bulimia patients.
The insula “is a region that integrates body perception, gustatory information, reward and emotion, functions known to be disturbed in these patients,” explained Dr. Koen Van Laere, the study’s lead author.
“The role of endocannabinoids in appetite control is clearly important. These new data point to important connections between this system and eating disorders,” added Dr. John Krystal, Editor of Biological Psychiatry.
Additional research is now needed to establish whether the observed changes are caused by the disease or whether these are neurochemical alterations that serve as risk factors for developing an eating disorder.
Researchers hope the findings may lead to a potential new target for developing drugs to treat eating disorders – a practice that is currently being investigated in animal models.