Women who have had a certain type of anorexia nervosa show an alteration of the activity of a chemical in their brain that is widely associated with anxiety and other affective disorders more than one year after recovery, according to a study in the September issue of Archives of General Psychiatry.
Anorexia nervosa, a disorder characterized by the relentless pursuit of thinness and obsessive fear of being fat, has two subtypes, a group that restricts their eating (restricting-type AN) and a group that alternates restrictive eating with bulimic symptoms such as episodes of purging and/or binge eating (bulimia-type AN), according to background information in the article. Previous evidence has suggested that alterations in the activity of serotonin (a brain chemical involved in communication between nerve cells) may contribute to the appetite alteration in anorexia nervosa as well as playing a role in anxious, obsessional behaviors and extremes of impulse control.
Ursula F. Bailer, M.D., of the University of Pittsburgh School of Medicine, Pittsburgh, and colleagues compared the activity of serotonin in women who had recovered from each of the two types of anorexia nervosa and a control group of healthy women using positron emission tomography (PET). The researchers injected a molecule that can bind to a serotonin receptor in much the same way that serotonin does into specific areas of the women's brains and used PET scans to measure the extent of the molecule-receptor binding. This molecule-receptor binding served as a marker for alterations of serotonin neuronal activity. Thirteen women recovered from restricting-type AN, 12 women with bulimia-type AN and 18 healthy control women were included in the study.