Finding a Better Definition for EDNOS

A call for changing the current definition.

In the DSM-IV, the diagnosis of EDNOS groups what some clinicians view as “a hodgepodge” of  eating disorders patients, and the EDNOS label may give the false impression that these patients actually have a single eating disorder. Dr. Pamela K. Keel of Florida State University, Tallahassee, and colleagues at the University of Denver and the Neuropsychiatric Research Institute, Fargo, ND, believe it’s time to change the current definition of EDNOS.

The authors point out that the symptoms of purging disorder (PD) and binge eating disorder (BED) are distinct enough to support dividing EDNOS into at least two types on the DSM-V. The authors designed a study to demonstrate this point (Int J Eat Disord 2011; 44:311).

In the study, 41 women with DSM-IV diagnoses of BED, 33 women with PD, and 35 control women with no history of eating disorders were recruited through community-based advertisements. Noting that BED is often associated with obesity, and PD has been identified in normal-weight individuals, the authors specifically recruited women with BED who fell into one of two body mass index (BMI) ranges: those with BMIs of 18.5 to 26.5 kg/m² (BED normal weight group) and those with BMIs greater than 30 kg/m² (BED obese group).The BMI range for the normal-weight group was selected to match that used for recruitment of women in the PD and control groups.

The women all completed structured clinical interviews and self-report questionnaires during a single in-person assessment session. During this session, height and weight were measured using a digital scale and stadiometer. All participants also completed the Structured Clinical interview of Axis I Disorders (SCID-1), the Beck Depression Inventory, the Body Shape Questionnaire, and the Three Factor Eating Questionnaire.

Three distinct disorders

The results supported the clinical significance of three distinct types of eating disorders, based on the presence of higher levels of depression and greater levels of Axis I disorders among women with BED, compared with controls. Several distinctions were noted between PD and BED: specifically, women with PD reported higher body image disturbances compared with normal-weight BED women. Compared with both the obese and normal-weight BED groups, those with PD reported significantly greater dietary restraint and body dissatisfaction. Compared with the obese BED group, women with PD had a lower prevalence of impulse control disorders.

According to the authors, these findings support differentiating among EDNOS patients based on behavioral presentation, in both research and future nosological schemes, such as those that will be included in the DSM-V.