A major study, coordinated by neuroscientists at the University of Bath (UK) with international partners, has revealed key differences in brain structure between people with and without anorexia nervosa.
Anorexia, which is a serious eating disorder and mental illness, affects more than a quarter of a million people aged 16 and over in the UK. Symptoms are characterized by people trying to keep their weight as low as possible by not eating enough.
Understanding why some people develop anorexia while others is not yet largely unknown, although the biological factors are widely recognized. These new findings, which are based on extensive analysis of brain scans performed on patients around the world and are published in the journal Biological Psychiatry, answer the question.
They reveal that people with anorexia show “significant reductions” in three critical measures of the brain: cortical thickness, subcortical volumes, and cortical surface area. Reductions in brain size are significant because they are thought to involve the loss of brain cells or the connections between them.
The results are some of the clearest so far to show links between structural changes in the brain and eating disorders. The team says the size of the effect of their study for anorexia is, in fact, the largest of any psychiatric disorder investigated to date.
This means that people with anorexia showed reductions in brain size and shape between two and four times greater than people with conditions such as depression, ADHD or OCD. The observed changes in brain size for anorexia can be attributed to reductions in people’s body mass index (BMI).
Based on the results, the team stresses the importance of early treatment to help people with anorexia avoid long-term brain structural changes. Existing treatment usually includes forms of cognitive-behavioral therapy and, most importantly, weight gain. Many people with anorexia are treated successfully and these results show the positive impact that this treatment has on the structure of the brain.
His study included nearly 2,000 pre-existing brain scans for people with anorexia, including people in recovery and “healthy controls” (people who don’t have anorexia or recovery). For people recovering from anorexia, the study found that reductions in brain structure were less severe, implying that with proper early treatment and support, the brain might be able to repair -se.
For this study, we have worked intensively for several years with research teams from around the world. Being able to combine thousands of brain scans of people with anorexia allowed us to study in much more detail the brain changes that could characterize this disorder.
We found that large reductions in brain structure, which we observed in patients, were less noticeable in patients who were already on their way to recovery. This is a good sign, because it indicates that these changes may not be permanent. With the right treatment, the brain could recover. “
Dr. Esther Walton, Principal Investigator, Department of Psychology, University of Bath
The research team also involved academics working at the Technical University of Dresden, Germany; Mount Sinai Icahn School of Medicine, New York; and King’s College London.
The team worked together as part of the ENIGMA Eating Disorders working group, managed at the University of Southern California. The ENIGMA Consortium is an international effort to bring together researchers in imaging genomics, neurology and psychiatry, to understand the link between brain structure, function and mental health.
“The international scale of this work is extraordinary,” said Paul Thompson, Professor of Neurology and Senior Scientist at the ENIGMA Consortium. “Scientists from 22 centers around the world pooled their brain scans to create the most detailed picture to date of how anorexia affects the brain. Brain changes in anorexia were more severe than in any other condition. “The effects of treatments and interventions can now be assessed using these new brain maps as a reference.”
He added: “This study is new in terms of the thousands of brain scans analyzed, which reveal that anorexia affects the brain more deeply than any other psychiatric illness. This is really a wake-up call, which shows the need for ‘Early Interventions for People with Eating Disorders.’
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Magazine reference:
Walton, E., et al. (2022) Brain structure in individuals with anorexia nervosa with acute weight and partially restored weight: coordinated analysis of the ENIGMA Eating Disorders working group. Biological Psychiatry. doi.org/10.1016/j.biopsych.2022.04.022.