Improving Identification and Treatment of Eating Disorders

The ICD-11 represents a significant advance in classification of Feeding and Eating Disorders. One of the most important improvements will be the reduction of the percentage of disorders that fall into an unspecified category. With the ICD-10, the majority of diagnoses for Feeding and Eating Disorders were classified as Unspecified Eating Disorder. This is unsatisfactory as, besides the fact that this category may not always be accepted for insurance reimbursement purposes, it does not provide information about the clinical picture of the patient, prognosis or expected outcomes, or which treatments may be most effective.  

Two major changes in the guidelines for Feeding and Eating Disorders will help to reduce the usage of the unspecified category. First, the Working Group on the Classification of Feeding and Eating Disorders recommended broadening some of the existing categories to include atypical cases that don’t exhibit the classic symptom profile for a particular disorder. Such cases can have health impacts that are just as serious as in more "typical" cases, and therefore deserve treatment. The proposed diagnostic guidelines better address many of these cases. For example, a patient who does not present with amenorrhea would not be diagnosed with Anorexia Nervosa in ICD-10, but in ICD-11 she would be, which means that she would have access to treatment and would therefore have a better prognosis. Similarly for Bulimia Nervosa, patients with a low frequency of binge eating and purging or who experience loss of control when eating an amount of food that is not objectively very large (subjective binge-eating) would not have been diagnosed under ICD-10, but will be under the proposed ICD-11 guidelines. 

Two new disorders that are recommended for inclusion in the ICD-11 will also reduce the proportion of  unspecified diagnoses:

Binge Eating Disorder has been under investigation for more than 25 years, so there is a great deal of evidence to support its validity and clinical utility. This diagnosis is similar to Bulimia Nervosa in that it involves frequent, recurrent binge eating behaviour. However, the individual does not engage in compensatory behaviours to avoid weight gain such as vomiting or abusive use of laxatives or diuretics (purging behaviours) as people with bulimia do. As a consequence, Binge Eating Disorder is often associated with obesity. People with Binge Eating Disorder can suffer from metabolic syndromes and other medical complications associated with overweight, as well as impairments in functioning.

The other new disorder is Avoidant-Restrictive Food Intake Disorder (ARFID), which was poorly described in the ICD-10 in the category Feeding and Eating Disorders in Childhood and Infancy. In the ICD-11, we have developed better clinical guidelines for this disorder, which involves eating an insufficient quantity or variety of foods to meet nutritional requirements. Individuals with ARFID can be severely underweight and may even require inpatient treatment and supplemental nutrition.  

The inclusion of these 2 new disorders will allow clinicians to recognize and treat these serious conditions earlier in order to avoid negative impacts on physical and mental health throughout the lifespan. 

The proposed ICD-11 diagnostic guidelines for Feeding and Eating Disorders performed very well in the WHO case-controlled study. Diagnostic accuracy and agreement improved for all disorders, and clinicians rated the new guidelines as significantly more clinically useful. The addition of the 2 new disorders and the broadening the essential features of existing disorders clarified the diagnostic landscape, providing an improved basis for diagnostic decision-making. Improvements have been made in the guidelines on the basis of the study results. Our next step will be to test these guidelines in clinical settings around the world.