Comparing operational definitions of DSM-5 anorexia nervosa for research contexts

OBJECTIVE

DSM-5 anorexia nervosa (AN) criteria include several changes that increase reliance on clinical judgment. However, research contexts require operational definitions that can be applied reliably and that demonstrate validity. The present study evaluated different operational definitions for DSM-5 AN.

METHOD

DSM-5 AN criteria were applied to diagnostic interview data from 364 women varying two features: threshold for determining low weight for Criterion A (body mass index [BMI] <17.0 kg/m(2) vs. <18.5 kg/m(2)) and explicit endorsement of weight phobia (Criterion B explicit vs. inferred). Resulting groups of individuals with DSM-5 AN were compared on estimated frequency. In addition, AN groups were compared to non-eating disorder controls and individuals with an other specified feeding or eating disorder (OSFED) on external validators.

RESULTS

All operational DSM-5 definitions produced higher lifetime frequency estimates than reported for DSM-IV AN, with a particularly large increase associated with the broadest definition. All definitions produced significant differences in comparison to controls on external validators that were associated with medium to large effect sizes. Only definitions that required a lower weight threshold or explicit endorsement of weight phobia demonstrated significant differences compared to OSFED on external validators, and these were of small effect size. The specific combination of BMI <18.5 kg/m(2) with inferred weight phobia exhibited few meaningful distinctions from the OSFED group.

DISCUSSION

To balance inclusivity, syndromal reliability, and validity, an operational definition for DSM-5 AN in research contexts should define low weight as BMI <18.5 kg/m(2) and require measurable rather than inferred weight phobia.

From DSM-IV to DSM-5: changes to eating disorder diagnoses

PURPOSE OF REVIEW

This article reviews the modifications to eating disorders that appear in the 'Feeding and Eating Disorders' chapter of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). These modifications include the addition of three disorders (avoidant/restrictive food intake disorder, rumination disorder, and pica) previously described in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR) section 'Feeding and Eating Disorders of Infancy or Early Childhood'; clarifications and modifications to anorexia nervosa and bulimia nervosa; and the inclusion of binge eating disorder as a formal diagnosis.

RECENT FINDINGS

Research suggests that the majority of individuals seeking treatment for an eating disorder are classified as eating disorder not otherwise specified based on DSM-IV criteria. Using DSM-5 criteria, many of these individuals will be reassigned to a diagnosis with greater clinical utility. A large body of research also supports the inclusion of binge eating disorder as a formal diagnosis.

SUMMARY

The changes to eating disorders, recommended by the Eating Disorders Work Group, aim to clarify existing criteria and to decrease the frequency with which individuals are assigned to the heterogeneous residual category, eating disorder not otherwise specified, which provides little clinical utility.