What to do about atypical anorexia nervosa? Commentary on Walsh et al. (2023)

Changes made to the DSM Eating Disorders over the years have aimed to reduce the prevalence of the residual DSM Eating Disorder categories (e.g., Other Specified Eating Disorder). Atypical Anorexia Nervosa (AN), included since DSM-IV as an example of a presentation not meeting criteria for a specific eating disorder, appears to be more prevalent than AN. It is defined as meeting all of the criteria for AN except that, after significant weight loss, weight is at or above normal. As suggested by the Walsh et al. review, lack of definitional precision will likely complicate efforts to determine whether atypical AN is best considered a variant of AN or a distinct category. Problems with the current definition of atypical AN include (1) a lack of precision regarding what constitutes "significant" weight loss; (2) whether the weight loss can occur at any point in the individual's lifetime; and (3) whether there an upper limit to weight being above normal. It is suggested that researchers develop consensus diagnostic criteria and assessment tools to facilitate the collection of empirical data about atypical AN in order to lay the groundwork for future decisions about its nosological status.