The crucial role of the brain in eating disorders and the recovery process

Presented by Jeffrey DeSarbo, Medical Director at ED-180 Eating Disorder Treatment Programs

Eating disorders are complex, multifaceted conditions influenced by various biological, psychological, and sociological risk factors. Even defining an eating disorder can be as complicated as the recovery process; however, we know that the brain plays a crucial role in both the development and progression of eating disorders and the recovery process.

What is an eating disorder?

There are many approaches to defining and understanding eating disorders, including:1

  • Behavioral condition: Those with eating disorders tend to struggle with eating and control.
  • Cognitive condition: Those with eating disorders often experience distorted self-image and experience profound self-judgment.
  • Emotional condition: There is a lot of emotional fallout for people with an eating disorder, and they often have significant distress.
  • Psychiatric condition: It’s in the Diagnosis and Statistical Manual for Mental Disorders, Fifth Edition (DSM-5), and is a mental disorder that causes disturbances in mood, behavior, and thinking.
  • Medical condition: Psychiatry is a sub-specialty of medicine

The medical-psychiatric component makes it different than other psychiatric issues, such as depression or anxiety.

What is eating disorder recovery?

It’s been hard for professionals to reach a consensus on what defines eating disorder recovery. Many people are proponents of the idea that people always have their eating disorders, much like someone who has stopped drinking will always be an alcoholic. On the other hand, some eating disorder professionals believe that individuals in recovery don’t have an eating disorder anymore. 

The DSM-5 definition of recovery only tells part of the story. It focuses on:1

  • Physical parameters, such as weight stabilization, normal medical labs, and normal EKG
  • Behavioral parameters, like eating three meals a day and stopping disordered eating symptoms
  • Cognitive parameters, like fear of food and weight gain, are no longer present. 

However, this definition ignores the neurobiological restoration component—many neuroscientists believe that only when the brain restores itself to baseline can a person actually experience a subjective experience of feeling recovered from their condition. 

Recovery in scientific terms

Restoration to the baseline of neurobiological processes results in stabilized body and brain function as well as mental function processing. This can be achieved through a combination of treatment modalities, such as:

  • Psychotherapy
  • Nutritional rehabilitation
  • Medical stabilization

Every member of the treatment team works together to provide integrated and comprehensive care to bring about long-term change. But ultimately, what’s happening with all of these methods is that the treatment team is working on restoring the brain and central nervous system to baseline.

Key question for monitoring recovery

When determining whether patients are in recovery or not, neurobiological professionals may ask, what percentage of your thoughts do you spend thinking about worrying about food, weight, body image, caloric intake, exercise, body-checking, purging, restricting, and self-worth?

Many patients say about 90-100% of their free thoughts are about these things, which is the true distress behind an eating disorder. They may even exhibit zero behaviors, but that percentage of time is spent worrying. That’s the nature of an eating disorder, making it challenging to live life.

Neurobiology in eating disorders

Eating disorders cause physical and functional changes in the brain. Various brain scans, such as CAT scans, PET scans, and fMRI scans, have found:2

  • Loss of brain mass
  • Loss of brain anatomy
  • Changes in brain chemistry
  • Changes in brain blood flow
  • Changes in neuro-hormones

Changes in brain functioning typically result in changes in thought and cognitive processing.

Eating disorders and the brain-body axis

When the brain structure and function change, these changes can affect all other systems, such as:

  • Central nervous system (CNS)
  • Gastrointestinal system
  • Cardiovascular
  • Pulmonary
  • Renal
  • Endocrine
  • Reproductive
  • Immune
  • Musculoskeletal

The brain, of course, is tied in with all other systems. Consequently, patients with eating disorders tend to experience many medical complications. And when someone experiences a medical condition associated with an eating disorder, signals are sent back to the brain from that particular system that regulates how the brain functions. Because the brain affects the body systems and the body systems affect the brain, someone with an eating disorder often experiences a feedback loop or cycle that perpetuates the disorder.

Adipose tissue as the forgotten endocrine organ

When we think about the endocrine system, many people don’t think about adipose tissue or body fat. However, adipose tissue is an organ required for life and healthy functioning. It plays a vital role in endocrine function. It produces and manufactures all these biological peptides that regulate the body’s hormone systems.4

When someone struggles with severe anorexia and their body’s fat content is minimal, they’re likely to experience severe endocrine problems, such as osteoporosis and menstrual disturbances.4

Genetic influence on eating disorders

Like many medical and psychiatric conditions, there is a strong genetic component to eating disorders. Researchers estimate the following heritability for each eating disorder:5

People can be predisposed to an eating disorder, and something in the environment can trigger the onset of it—this is known as epigenetics. Things that can trigger the onset of an eating disorder include:

  • Trauma
  • Stressors
  • Personality traits
  • Medical states and diseases
  • Social and interpersonal interactions
  • Child-rearing 
  • Exposure to dieting and exercise
  • Illicit drugs
  • Socioeconomic status
  • Cultural expectations
  • Sexual identity
  • The need to be perfect

Changes in brain structure and function caused by EDs

Eating disorders can cause profound changes in the brain. From a neurobiological perspective, full recovery can’t happen until these brain deficiencies and losses have been rectified, and functioning and structure has been restored. This is based on the idea that if someone has an extreme drive to lose weight, even if they gain weight, they need to change that drive, which has changed the brain.

Here are some ways that eating disorders can damage the brain:6,7

  • Loss of grey matter (anywhere from 3.7% to 7.6%)
  • Loss of white matter (up to 3.8%)
  • Lower amygdala volume
  • Loss of cortical thickness

Different people experience damage in different areas. But no matter what, an eating disorder causes the brain to function poorly. In the case of bulimia and binge eating disorder, researchers have seen an increase in gray matter in the areas responsible for addictive patterns and reward.3 This shows how eating disorders are not just psychological but also an anatomical issue.

The goal of eating disorder treatment

Treatment and recovery can be complicated, and everyone’s journey is different. But no matter who you are, effective eating disorder treatment can help improve neurotransmission and functioning neural network. Important changes made in recovery begin on a molecular and cellular level. When people in recovery report feeling happier and experiencing better control, that is due to vital changes on the molecular level in the central nervous system.

These improvements can be achieved through:

  • Psychotherapy
  • Nutritional rehabilitation
  • Medical interventions for stabilizations
  • Psychiatric medications

There is a wealth of evidence that psychotherapy causes major changes in the brain in addition to medication. Psychotherapy tends to have a “top-down” approach, working on the outside cortical layer and then going deeper into the limbic system. In contrast, medications have a “bottom-up” approach, working deeper on neurotransmitters in the limbic system first and then flowing to the outer cortex, where we process thoughts and decision-making.

Working together, psychotherapy and medication can restore your brain to optimal functioning, helping you to improve your symptoms, mood, and behaviors.

Resources

  1. American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.).
  2. Esther Walton, Fabio Bernardoni, Victoria-Luise Batury, Klaas Bahnsen, Sara Larivière, Giovanni Abbate-Daga, et al. (2022). Brain Structure in Acutely Underweight and Partially Weight-Restored Individuals with Anorexia Nervosa - A Coordinated Analysis by the ENIGMA Eating Disorders Working Group. Biological Psychiatry, 92(9), 730-738.
  3. Frank, G. K. W., Shott, M. E., Stoddard, J., Swindle, S., & Pryor, T. (2021). Reward processing across the eating disorders spectrum implicates body mass index and ventral striatal-hypothalamic circuitry. JAMA Psychiatry, 78(10), 1123-1133.
  4. Smitka, K., & Marešová, D. (2015). Adipose Tissue as an Endocrine Organ: An Update on Pro-inflammatory and Anti-inflammatory Microenvironment. Prague medical report, 116(2), 87–111.
  5. Berrettini W. (2004). The genetics of eating disorders. Psychiatry, 1(3), 18–25.
  6. Nickel, K., Joos, A., Tebartz van Elst, L., Matthis, J., Holovics, L., Endres, D., Zeeck, A., Hartmann, A., Tüscher, O., & Maier, S. (2018). Recovery of cortical volume and thickness after remission from acute anorexia nervosa. The International Journal of Eating Disorders, 51(9), 1056–1069.
  7. Seitz, J., Konrad, K., & Herpertz-Dahlmann, B. (2018). Extend, Pathomechanism and Clinical Consequences of Brain Volume Changes in Anorexia Nervosa. Current Neuropharmacology, 16(8), 1164–1173.