DSM-IV threshold versus subthreshold bulimia nervosa

Objective: The purpose of the present work is to determine whether bulimia nervosa (BN) and eating disorder not otherwise specified, BN type (EDNOS-BN) were qualitatively distinct in terms of eating and general psychopathology. Method: This study presents a comparison of 138 women with BN and 57 with EDNOS-BN from a multisite study on eating-related and general psychopathology measures. Results: Although women with BN reported higher lifetime history rates of anorexia nervosa, greater binge eating and vomiting frequency, and more eating concerns, no significant differences were observed between groups on measures of perfectionism, impulsivity, obsessive-compulsiveness, anxiety, depressive symptomatology, or alcohol/substance problems. Based on the partial η² values, the distinction between BN and EDNOS-BN accounted for < 5% of the criterion variance in general psychopathology measures. Post hoc analyses comparing EDNOS-BN with objective bulimic episodes (OBEs; n = 34) versus no OBEs (n = 23) found greater EDEQ-4 Restraint subscale scores for EDNOS-BN without OBEs. However, there was no significant difference on the EDEQ-4 Eating Concern subscale between the two EDNOS-BN subgroups. Conclusion: The findings highlight the clinical significance of BN partial syndrome and prompt reevaluation of existing BN diagnostic boundaries. Post hoc analyses also underscore the need for greater differentiation within EDNOS.