Atypical anorexia nervosa can be just as bad

The case report and literature review by Rastogi and Rome in this issue reminds us that eating disorders can occur in patients with a wide variety of weights and that those who were previously overweight present differently from those with classic anorexia nervosa. The case presented meets the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria for atypical anorexia nervosa, which describes patients who have lost a significant amount of weight but whose weight remains in the normal or above-normal range.

Before the DSM-5 was published, most children, adolescents, and young adults seeking treatment at specialized eating disorder programs who did not meet the criteria for either anorexia nervosa or bulimia nervosa were assigned the diagnosis of “eating disorder not otherwise specified” (EDNOS). Revisions have since been made to the diagnostic criteria in DSM-5 to improve the clinical utility of the diagnostic categories. The EDNOS diagnosis has been eliminated and new diagnostic categories have been introduced, including atypical anorexia nervosa.

The proportion of patients with atypical anorexia nervosa in specialized eating disorder programs has increased dramatically, often accounting for 25% to 40% of patients admitted to inpatient units. The number of these patients presenting to one tertiary care inpatient service increased 5-fold over a period of 5 years.