title: Typical Versus Atypical Anorexia Nervosa Among Adolescents: Clinical Characteristics and Implications for ICD-11.
abstract: There is scant research on the clinical utility of differentiating International Classification of Diseases (ICD) 10 diagnoses F50.0 anorexia nervosa (typical AN) and F50.1 atypical anorexia. We reviewed systematically records of 47 adolescents who fulfilled criteria for ICD-10 F50.0 (n = 34) or F50.1 (n = 13), assessing the impact of diagnostic subtype, comorbidity, background factors and treatment choices on recovery. Atypical AN patients were significantly older (p = 0.03), heavier (minimum body mass index 16.7 vs 15.1 kg/m(2) , p = 0.003) and less prone to comorbidities (38% vs 71%, p = 0.04) and had shorter, less intensive and less costly treatments than typical AN patients. The diagnosis of typical versus atypical AN was the sole significant predictor of treatment success: recovery from atypical AN was 4.3 times (95% confidence interval [1.1, 17.5]) as likely as recovery from typical AN. Overall, our findings indicate that a broader definition of AN may dilute the prognostic value of the diagnosis, and therefore, ICD-11 should retain its distinction between typical and atypical AN.
authors.affiliation: Department of Public Health, University of Helsinki, Finland.|Department of Adolescent Psychiatry, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Yasmina
authors.initials: Y
authors.lastname: Silén
authors.affiliation: Department of Public Health, University of Helsinki, Finland.|Department of Adolescent Psychiatry, Helsinki University Central Hospital, Helsinki, Finland.|Institute of Clinical Medicine, Child Psychiatry, University of Turku, Finland.|Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Anu
authors.initials: A
authors.lastname: Raevuori
authors.affiliation: Department of Adolescent Psychiatry, The Hospital District of Helsinki and Uusimaa, Hyvinkää, Finland.|Finnish Student Health Service, Helsinki, Finland.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Jüriloo
authors.affiliation: Department of Adolescent Psychiatry, Helsinki University Central Hospital, Helsinki, Finland.
authors.forename: Veli-Matti
authors.initials: VM
authors.lastname: Tainio
authors.affiliation: Department of Adolescent Psychiatry, Helsinki University Central Hospital, Helsinki, Finland.|Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland.
authors.forename: Mauri
authors.initials: M
authors.lastname: Marttunen
authors.affiliation: Department of Public Health, University of Helsinki, Finland.
authors.forename: Anna
authors.initials: A
authors.lastname: Keski-Rahkonen
mesh_terms: D000293:Adolescent; D000553:Ambulatory Care; D000856:Anorexia Nervosa / Q000145:classification* / Q000175:diagnosis / Q000628:therapy*; D015992:Body Mass Index; D003362:Cost-Benefit Analysis; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D001523:Mental Disorders / Q000453:epidemiology; D015999:Multivariate Analysis; D011379:Prognosis; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: adolescent; anorexia nervosa; diagnosis; diagnostic classification; outcome; recovery