Anorexia and Body Dysmorphia Produce Similar Brain Activity Abnormalities
Eating disorders such as anorexia nervosa have been closely linked to body dysmorphic disorder (BDD), a psychiatric condition which causes an obsessive preoccupation with perceived flaws in personal physical appearance. Now, new research published in the journal Psychological Medicine has found these two conditions share biological similarities which may help us understand both conditions.
Researchers at the University of California, Los Angeles (UCLA) found that individuals with anorexia or BDD had abnormal activity within the visual cortex of the brain during the very first moments when the brain processes “global” information.
Global information is broad information or a perception of a whole, as opposed to the details and minutiae.
The findings lead the researchers to believe perceptual retraining could potentially be an effective therapy for treating both disorders. Perceptual retraining uses behavioral exercises focused on adjusting or correcting participant’s balance between global and detailed processing.
Individuals with both disorders are already instructed to try not to focus on details and process objects more globally, but these findings suggest more focused therapy may be more effective.
While previous research on body dysmorphic disorder has identified this type of abnormal activity in the visual cortex, this study is the first to directly link the locations of the abnormal activity with time periods immediately following the viewing of an image.
For the study, the researchers used functional magnetic resonance imaging, or fMRI, to identify regional abnormalities in visual processing and electroencephalography, or EEG, to evaluate the timeline for the brain’s processing of the signals. The team then compared the results of 15 people with BDD with 15 individuals diagnosed with anorexia nervosa and 15 healthy control participants.
“We now know that these abnormalities may be happening at the very early stages when the brain begins processing visual input, and that the similar distortions in perception shared by anorexia nervosa and body dysmorphic disorder may have similar neurobiological origins,” said Wei Li, a student in the UCLA Interdepartmental Ph.D. Program for Neuroscience and the study’s first author.
“This understanding has the potential to lead to new strategies that can improve the way we treat these disorders.”
The two conditions share many symptoms and strongly impact how individuals view their bodies. They are also frequently diagnosed together.
Anorexia nervosa produces a distorted perception of body weight and shape, which feeds the desire for unhealthy weight control measures such as abstaining from food. Similarly, body dysmorphic disorder causes people to view themselves as disfigured or ugly, despite the individual looking completely normal to others. Those experiencing the condition tend to fixate on the tiny details of their faces or bodies, which can lead to depression, anxiety, shame, and social functional impairment.
“Previously, we knew where these visual processing abnormalities existed in the brain in body dysmorphic disorder, but did not know when they were taking place,” said Dr. Jamie Feusner, the paper’s senior author, a UCLA associate professor of psychiatry.
“Now, knowing the timing, it is clearer that their perceptual distortions are more likely to be rooted early in their visual systems.
“Also, the fact that the results were recorded while people were viewing other people’s faces and images of houses suggests that this may be a more general abnormality in visual processing,” Feusner said.