Working to Better Define Eating Disorders in Youth

Results of an 8-year study to improve diagnosis in young patients by targeting symptoms.

Much remains to be defined in eating disorders among children and adolescents. As the Workgroup for Classification of Eating Disorders in Children and Adolescents recently reported, applying current diagnostic criteria to children and adolescents can be problematic (Eur Eat Disord Rev 2010; 18:79). For example, growth and weight gain are expected in children and adolescents, which is a challenge when using strict weight criteria for a diagnosis of anorexia nervosa (AN). Similarly, children and teens may be premenarcheal, making the amenorrhea criterion irrelevant. And, the cognitive eating disorder criteria, including extreme fear of weight gain, body image disturbances, and overvaluation of weight and shape, are difficult to assess and to apply to young patients, who may not have developed insight into motives for eating behavior. Current thresholds for AN and bulimia nervosa (BN) may be overly narrow, and relaxing the criteria would allow a subset of youth with eating disorders not otherwise specified (EDNOS) to be reclassified within broadened forms of AN or BN.

Study targets eating disorder symptoms

Because the current system may not be adequate for categorizing eating pathology in youth, the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-V) should consider recognizing children and teens with minimal cognitive eating disorder symptoms, according to Kamryn T. Eddy, PhD and colleagues. The authors recently reported the results of their 8-year study of young patients at the University of Chicago Medical Center (J Am Acad Child & Adoles Psychiatry 2010; 49:277).

Dr. Eddy and colleagues noted that the DSM-IV-TR does not make specific provisions for diagnosing eating disorders in children and adolescents and that to inform the new edition of the DSM-V, research is needed to determine whether the same groups of symptoms and presenting diagnoses seen in adults can be applied to youth. The authors designed a study of 401 youths aged 7 through 19 years who sought treatment for eating disorders at the University of Chicago Medical Center between October 2001 and April 2009. A total of 363 girls (90.5%) and 38 boys (9.5%) participated. Most were Caucasian (73.9%); 12.4% were Hispanic; 8.9% were African American; 2.0% were Asian; and 2.8% were identified as “another race/ethnicity.”

Before treatment, all patients were assessed with the Eating Disorder Examination (EDE), version 12.0D/C.2, the version adapted for children. DSM-IV-TR diagnoses of AN and BN were assigned, based on EDE-generated behavioral and cognitive symptoms. Eating disorders presentations that did not meet these criteria were categorized as EDNOS. The Beck Depression Inventory and Rosenberg Self-Esteem Scale were also administered before treatment. Then, latent profile analysis (LPA) was applied. LPA proposes that a heterogeneous group can be broken down to a finite number of homogeneous subgroups by minimizing associations among response across multiple indicators. In this way, LPA identifies the number and composition of unobserved latent groups, which themselves are mutually exclusive.

Three groups were identified

Three latent profile, or LP, groups were identified: LP1, including 144 patients with binge eating and purging (binge/purge); LP2, including 126 patients who were characterized by excessive exercise and extreme eating disorder cognitions (exercise-extreme cognitions); and LP3, 131 patients characterized by LPs that imperfectly resembled DSM-IV-TR eating disorders. Those in the LP1 group had characteristics resembling BN, while those in the LP2 and LP3 groups had characteristics that resembled AN with a relaxed weight criterion.

Dr. Eddy and her co-authors said that the identified LP groups were somewhat similar to those described in adult cases. However, rather than identifying several different bulimic spectrum latent groups, they found that youth with a predominance of these symptoms (such as binge eating and/or purging), clustered in a single latent group. The LP groups were more differentiated than the DSM-IV-TR categories across pretreatment eating disorder and general psychopathology indexes, as well as by weight change at follow-up. However, neither LP nor DSM-IV-TR categories predicted changes in binge/purge behaviors.

One interesting finding was that although there were few boys in this sample of patients, they were relatively more common in the group with the fewest typical eating disorder symptoms. According to the authors, this raises the possibility that boys with eating disorders may be more likely to show atypical symptoms than are girls.

The study results also suggest that latent profile analysis can be used to identify meaningful eating disorder phenotypes in a clinical sample of children and adolescents. Youths who regularly engage in binge eating and/or purging can be differentiated from those who do not. Youth who do not engage in these behaviors are more likely to be of lower weight and are organized into two groups distinguished by the presence of typical eating disorder cognitions and excessive exercise.

The authors suggest that many more ongoing studies, using developmentally sensitive assessment tools and a broad range of clinical indicators, are needed to prepare for the next version of the DSM.