Empirically Defining "Recurrent" Inappropriate Compensatory Behaviors: Differentiating Binge Eating Disorder From Bulimia Nervosa-Spectrum Disorders.

OBJECTIVE: For multiple disorders, DSM-5-TR criteria include "recurrent" engagement in behaviors-for example, in the criteria for binge-eating disorder (BED), "binge eating is not associated with the recurrent use of inappropriate compensatory behavior."-without operationalizing how frequently a behavior needs to occur to be considered "recurrent." This lack of specificity may be particularly problematic in diagnosing BED; BED shares features with bulimia nervosa (BN) but is differentiated based on lack of "recurrent" ICB engagement. Some treatments (e.g., behavioral weight loss) may be recommended for BED but are contraindicated for BN, making accurate diagnosis critical. We sought to determine what frequency of past-month inappropriate compensatory behaviors (ICBs) best distinguishes BED from BN. METHOD: 850 treatment-seeking adolescents and adults (76% female, Mage = 29) completed eating disorder and comorbid symptom questionnaires at program admission from 2020 to 2024. Structural Equation Modeling (SEM) Trees derived which ICB frequencies best distinguished diagnoses. RESULTS: SEM Tree analyses yielded four subgroups: past-month ICB frequency 0 (ICB0; n = 349); frequency 1-25 (ICB1; n = 307); frequency 26-55 (ICB2; n = 143); and frequency > 56 (ICB3; n = 51). ICB0 differed from higher frequency groups on 11/12 clinical characteristics, ICB1 differed from higher frequency groups on 11/12 characteristics, and ICB2 differed from ICB3 on 1/12 characteristics. DISCUSSION: Findings suggest one past-month ICB may appropriately distinguish between BED and BN, though it remains unclear how fasting may impact this categorization. While more research is needed, DSM's diagnostic criteria may require revision to specify that the presence of any past-month vomiting, laxative use, or maladaptive exercise should preclude a BED diagnosis.