Brain Imaging Studies Reveal Neurobiology of Eating Disorders

Current treatments for anorexia and bulimia nervosa, which afflict an estimated 10 to 24 million Americans, are often limited and ineffective. Patients relapse. They become chronically ill. They face a higher risk of dying.

“A major reason contributing to the difficulty in developing new treatments for these disorders is our limited understanding of how brain function may contribute to eating disorder symptoms,” said Walter H. Kaye, MD, professor of psychiatry and director of the Eating Disorder Treatment and Research Program at the University of California, San Diego School of Medicine.

In recent, published papers, Kaye and colleagues report the situation is changing. Advanced brain imaging technologies, supported by grants from the National Institute of Mental Health, are beginning to be used to study and improve eating disorder treatments. Indeed, with funding from the Global Foundation for Eating Disorders (GFED), a New York City-based group that promotes eating disorder (ED) research and improved treatments, the UC San Diego Eating Disorders Center for Treatment and Research has launched a new initiative to create more effective ED therapies based upon brain imaging studies.

“Brain imaging research has allowed for a shift from simply describing a symptom to understanding the cause of a symptom,” said Kaye. “In the case of anorexia nervosa, imaging studies have helped us understand why people avoid eating and food and develop treatments that address the cause of the problem rather than secondary behaviors or symptoms.

“This is an important shift in the world of psychiatry similar to what revolutionized medical care decades ago. Today, if you show up at the doctor’s office with a bad cough, he or she might run diagnostics to determine whether the cough was bacterial or viral in order to administer the appropriate treatment. Similarly, the more we understand the specific causes of eating disorders, the more effective and targeted our treatments can become.”

The UC San Diego program, under the directorship of Kaye, Kerri Boutelle, PhD, associate professor of pediatrics and psychiatry, Leslie Karwoski Anderson, PhD, clinical assistant professor of psychiatry and GFED scholars Stephanie Knatz and June Liang, is developing an imaging-based treatment package specifically to address the neurobiology of anorexia nervosa, in which patients obsess about being or becoming overweight. To prevent weight gain or lose weight, people with anorexia nervosa typical may starve themselves or exercise excessively.

Living With Food: The Science Supporting Eating Disorder Treatment

One of the questions that frequently arises in eating disorder treatment is why a disconnect often exists between knowledge that eating disorder behaviors are dangerous for one’s health and the ability to stop these behaviors. An individual with an eating disorder will probably know that people around them are worried about what they weigh, that purging is dangerous, that exercising compulsively is not a good idea, and that eating disorders result in serious and potentially lethal medical complications, but for so many people knowing these things does not result in behavioral change. In some ways this is what makes eating disorders so difficult to treat and to recover from. We are used to the idea that if we are aware of something and accept it as being true that we will change our behaviors, or attempt to change our behaviors, so that we can be healthier and have a higher quality of life. With eating disorders this is often not the case.

Although our understanding of biology is still at the early stage, the essential characteristics of eating disorders appears to be that the awareness that occurs is not of the true impact of the eating disorder on one’s body or life. By this we mean that awareness happens on some sort of cognitive or surface level but does not happen in a way that connects the various parts of the brain necessary to translate the surface awareness into behavioral change. As a result, just knowing you have an eating disorder doesn’t actually give a person information about how to get better. This part of the brain has not been fully formed or is not working adequately. This is why it is so ineffective to tell someone with an eating disorder “just eat”.


By, Dr. Mark Warren

Kaye said one neurobiological target of anorexia and other eating disorders is anxiety. Most people get irritable when they do not eat and experience eating as both a reward and pleasant experience. Conversely, anorexic individuals frequently feel extreme anxiety when eating food – or even just anticipating eating – which results in severely reducing their food intake as a means of reducing their feelings of anxiety.

“Recent imaging research has uncovered specific alterations in the brain associated with this link between food and anxiety in anorexic individuals,” said Kaye. “This finding is important because it helps explain the of cause food restriction, the most critical and dangerous behavior in anorexia.”

Cognitions and Emotions in Eating Disorders
The cognitive model of eating disorders (EDs) states that the processing of external and internal stimuli might be biased in mental disorders. These biases, or cognitive errors, systematically distort the individual’s experiences and, in that way, maintains the eating disorder. This chapter presents an updated literature review of experimental studies investigating these cognitive biases. Results indicate that ED patients show biases in attention, interpretation, and memory when it comes to the processing of food-, weight-, and body shape-related cues. Some recent studies show that they also demonstrate errors in general cognitive abilities such as set shifting, central coherence, and decision making. A future challenge is whether cognitive biases and processes can be manipulated. Few preliminary studies suggest that an attention retraining and training in the cognitive modulation of food reward processing might be effective strategies to change body satisfaction, food cravings, and eating behavior.

Cognitive-Behavioral Flexibility in Anorexia Nervosa
Anorexia Nervosa (AN) patients are characterized by perfectionism and obsessional personality traits. This anorectic personality type is associated with an exaggerated cognitive control and impaired cognitive-behavioral flexibility. Neuropsychological studies addressing flexibility have supported an impaired cognitive set-shifting (i.e., concrete and rigid behaviors to changing rules) as well as an impaired behavioral response shifting (i.e., stereotyped or perseverative behaviors) in AN patients independent of nutritional status and body weight. Furthermore, impaired set-shifting was found in healthy sisters of AN patients suggesting that cognitive inflexibility is a trait marker in AN patients. Brain imaging studies have provided new insights in striatocortical circuit dysfunctions that may underlie both the clinical symptoms of obsessive-compulsive personality traits and the neuropsychological observations of impaired cognitive-behavioral flexibility. The conceptualization of AN as a neurodevelopmental striatocortical disorder may help to develop new promising treatment approaches for this severe disorder.


Hans-Christoph Friederich,
Wolfgang Herzog

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