title: Bulimia nervosa-nonpurging subtype: closer to the bulimia nervosa-purging subtype or to binge eating disorder?
abstract: OBJECTIVE
  DSM-5 has dropped subtyping of bulimia nervosa (BN), opting to continue inclusion of the somewhat contentious diagnosis of BN-nonpurging subtype (BN-NP) within a broad BN category. Some contend however that BN-NP is more like binge eating disorder (BED) than BN-P. This study examines clinical characteristics, eating disorder symptomatology, and Axis I comorbidity in BN-NP, BN-P, and BED groups to establish whether BN-NP more closely resembles BN-P or BED.
  
  
  METHODS
  Women with BN-P (n = 29), BN-NP (n = 29), and BED (n = 54) were assessed at baseline in an outpatient psychotherapy trial for those with binge eating. Measures included the Structured Clinical Interviews for DSM-IV, Eating Disorder Examination, and Eating Disorder Inventory-2.
  
  
  RESULTS
  The BN-NP subtype had BMIs between those with BN-P and BED. Both BN subtypes had higher Restraint and Drive for Thinness scores than BED. Body Dissatisfaction was highest in BN-NP and predicted BN-NP compared to BN-P. Higher Restraint and lower BMI predicted BN-NP relative to BED. BN-NP resembled BED with higher lifetime BMIs; and weight-loss clinic than eating disorder clinic attendances relative to the BN-P subtype. Psychiatric comorbidity was comparable except for higher lifetime cannabis use disorder in the BN-NP than BN-P subtype
  
  
  CONCLUSIONS
  These results suggest that BN-NP sits between BN-P and BED however the high distress driving inappropriate compensatory behaviors in BN-P requires specialist eating disorder treatment. These results support retaining the BN-NP group within the BN category. Further research is needed to determine whether there are meaningful differences in outcome over follow-up.
authors.affiliation: Department of Psychological Medicine, University of Otago, Christchurch, New Zealand; Canterbury District Health Board, Christchurch, New Zealand.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Jordan
authors.forename: Virginia V W
authors.initials: VV
authors.lastname: McIntosh
authors.forename: Janet D
authors.initials: JD
authors.lastname: Carter
authors.forename: Sarah
authors.initials: S
authors.lastname: Rowe
authors.forename: Kathryn
authors.initials: K
authors.lastname: Taylor
authors.forename: Christopher M A
authors.initials: CM
authors.lastname: Frampton
authors.forename: Janice M
authors.initials: JM
authors.lastname: McKenzie
authors.forename: Janet
authors.initials: J
authors.lastname: Latner
authors.forename: Peter R
authors.initials: PR
authors.lastname: Joyce
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D056912:Binge-Eating Disorder / Q000145:classification* / Q000175:diagnosis / Q000523:psychology; D001828:Body Image / Q000523:psychology; D015992:Body Mass Index; D002032:Bulimia / Q000145:classification* / Q000175:diagnosis / Q000523:psychology; D052018:Bulimia Nervosa / Q000145:classification* / Q000175:diagnosis / Q000523:psychology; D015928:Cognitive Behavioral Therapy; D015897:Comorbidity; D003627:Data Interpretation, Statistical; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D007407:Interviews as Topic; D009520:New Zealand; D011569:Psychiatric Status Rating Scales; D011594:Psychometrics; D012959:Socioeconomic Factors; D013851:Thinness / Q000145:classification; D055815:Young Adult
keywords: DSM-5; binge eating disorder; bulimia nervosa; bulimia nervosa nonpurging; classification; subtype