title: Cognitive behaviour therapy response and dropout rate across purging and nonpurging bulimia nervosa and binge eating disorder: DSM-5 implications.
abstract: BACKGROUND
  With the imminent publication of the new edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), there has been a growing interest in the study of the boundaries across the three bulimic spectrum syndromes [bulimia nervosa-purging type (BN-P), bulimia nervosa-non purging type (BN-NP) and binge eating disorder (BED)]. Therefore, the aims of this study were to determine differences in treatment response and dropout rates following Cognitive Behavioural Therapy (CBT) across the three bulimic-spectrum syndromes.
  
  
  METHODS
  The sample comprised of 454 females (87 BED, 327 BN-P and 40 BN-NP) diagnosed according to DSM-IV-TR criteria who were treated with 22 weekly outpatient sessions of group CBT therapy. Patients were assessed before and after treatment using a food and binging/purging diary and some clinical questionnaires in the field of ED. "Full remission" was defined as total absence of binging and purging (laxatives and/or vomiting) behaviors and psychological improvement for at least 4 (consecutive).
  
  
  RESULTS
  Full remission rate was found to be significantly higher in BED (69.5%) than in both BN-P (p < 0.005) and BN-NP (p < 0.001), which presented no significant differences between them (30.9% and 35.5%). The rate of dropout from group CBT was also higher in BED (33.7%) than in BN-P (p < 0.001) and BN-NP (p < 0.05), which were similar (15.4% and 12.8%, respectively).
  
  
  CONCLUSIONS
  Results suggest that purging and non-purging BN have similar treatment response and dropping out rates, whereas BED appears as a separate diagnosis with better outcome for those who complete treatment. The results support the proposed new DSM-5 classification.
authors.forename: Zaida
authors.initials: Z
authors.lastname: Agüera
authors.forename: Nadine
authors.initials: N
authors.lastname: Riesco
authors.forename: Susana
authors.initials: S
authors.lastname: Jiménez-Murcia
authors.forename: Mohammed Anisul
authors.initials: MA
authors.lastname: Islam
authors.forename: Roser
authors.initials: R
authors.lastname: Granero
authors.forename: Enrique
authors.initials: E
authors.lastname: Vicente
authors.forename: Eva
authors.initials: E
authors.lastname: Peñas-Lledó
authors.forename: Jon
authors.initials: J
authors.lastname: Arcelus
authors.forename: Isabel
authors.initials: I
authors.lastname: Sánchez
authors.forename: Jose Manuel
authors.initials: JM
authors.lastname: Menchon
authors.affiliation: CIBER Fisiopatología de la Obesidad y Nutrición (CIBERobn), Instituto Salud Carlos III, Madrid, Spain. ffernandez@bellvitgehospital.cat.
authors.forename: Fernando
authors.initials: F
authors.lastname: Fernández-Aranda
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D056912:Binge-Eating Disorder / Q000145:classification / Q000523:psychology / Q000628:therapy*; D052018:Bulimia Nervosa / Q000145:classification / Q000523:psychology / Q000628:therapy*; D015928:Cognitive Behavioral Therapy; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D008875:Middle Aged; D010352:Patient Dropouts / Q000523:psychology*; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D055815:Young Adult