Validity and utility of the DSM-5 severity specifier for binge-eating disorder

Objective: To test both the concurrent and predictive significance of the new DSM-5 severity specifier for binge-eating disorder (BED) in adult outpatients. Method: Existing data from 195 adults with DSM-5 BED who received evidence-based treatment (manual-based cognitive-behavioral therapy) in an outpatient setting were re-analysed to examine whether these patients sub-grouped according to the DSM-5 severity levels, defined by the frequency of binge-eating (BE) episodes, would show meaningful differences in a range of variables of clinical interest assessed at pre-treatment and end-of treatment abstinence from BE. Results: Participants categorized with mild (33.3% of the sample), moderate (35.4%), severe (15.9%), and extreme (15.4%) severity of BED, based on their pre-treatment clinician-rated frequency of BE episodes, differed significantly from each other in physical characteristics (body mass index) and another sixteen variables of clinical interest assessed at pre-treatment regarding eating disorder psychopathology and putative maintenance factors, lifetime and current psychiatric disorder comorbidity, general psychiatric distress, and psychosocial impairment. The four DSM-5 severity groups were statistically indistinguishable in demographics or age-of-BED onset. However, significant between-group differences were observed in the treatment outcome, i.e., abstinence from BE, achieved by 98.5%, 66.7%, 38.7% and 6.7% of participants categorized with mild, moderate, severe, and extreme severity respectively. The outcome analyses repeated in the completer sample (n = 187) yielded the same pattern of the aforementioned intent-to-treat (N = 195) results. Discussion: The findings provide support for the severity specifier for BED introduced in the DSM-5 as a means of addressing within-group variability in severity.