Background: DSM-IV eating disorder (ED) diagnoses have been criticized for lack of clinical utility, diagnostic instability, and over-inclusiveness of the residual category "ED not otherwise specified" (EDNOS). Revisions made in DSM-5 attempt to generate a more scientifically valid and clinically relevant system of ED classification. The aim with the present study was to examine clinical characteristics and distinctiveness of the new DSM-5 ED diagnoses, especially concerning purging disorder (PD).
Methods: Using a large naturalistic Swedish ED database, 2233 adult women were diagnosed using DSM-5. Initial and 1-year follow-up psychopathology data were analyzed. Measures included the Eating Disorder Examination Questionnaire, Structural Eating Disorder Interview, Clinical Impairment Assessment, Structural Analysis of Social Behavior, Comprehensive Psychiatric Rating Scale, and Structured Clinical Interview for DSM-IV Axis I Disorders.
Results: Few meaningful differences emerged between anorexia nervosa binge/purge subtype (ANB/P), PD, and bulimia nervosa (BN). Unspecified Feeding and Eating Disorders (UFED) showed significantly less severity compared to other groups.
Conclusions: PD does not appear to constitute a distinct diagnosis, the distinction between atypical AN and PD requires clarification, and minimum inclusion criteria for UFED are needed. Further sub-classification is unlikely to improve clinical utility. Instead, better delineation of commonalities is important.
Keywords: Clinical distinctiveness; DSM-5; Eating disorders; Purging disorder.