title: An epidemiological and diagnostic study of Asperger syndrome according to four sets of diagnostic criteria.
abstract: OBJECTIVE
  This study evaluated the diagnostic process and prevalence rates of Asperger syndrome (AS) according to the DSM-IV, ICD-10, and criteria developed by Gillberg and Gillberg and by Szatmari and colleagues and clarified confusion about AS.
  
  
  METHODS
  An epidemiological study of 5,484 eight-year-old children in Finland, 4,422 (80.6%) of whom rated on the high-functioning Autism Spectrum Screening Questionnaire by parents and/or teacher, 125 of them screened and 110 examined by using structured interview, semistructured observation, IQ measurement, school day observation, and patient records. Diagnoses were performed by following the DSM-IV, ICD-10, and criteria developed by Gillberg and Gillberg and by Szatmari and colleagues in detail.
  
  
  RESULTS
  The prevalence rates per 1,000 were 2.5 according to the DSM-IV, 2.9 to ICD-10, 2.7 to Gillberg and Gillberg's criteria, and 1.6 to the criteria of Szatmari et al.
  
  
  CONCLUSIONS
  The results emphasize the need to reconsider the diagnostic criteria of AS. The importance of multi-informant sources came up, and the need of several informants was highlighted, especially when diagnosing the broader pervasive developmental disorders.
authors: All of the authors are with the Clinic of Child Psychiatry, University and University Hospital of Oulu, Finland, with the exception of Mr. Bloigu, who is with the Medical Faculty, University of Oulu, Finland. Electronic address: marja-leena.mattila@fimnet.fi.
authors: Marja-Leena
authors: ML
authors: Mattila
authors: All of the authors are with the Clinic of Child Psychiatry, University and University Hospital of Oulu, Finland, with the exception of Mr. Bloigu, who is with the Medical Faculty, University of Oulu, Finland.
authors: Marko
authors: M
authors: Kielinen
authors: All of the authors are with the Clinic of Child Psychiatry, University and University Hospital of Oulu, Finland, with the exception of Mr. Bloigu, who is with the Medical Faculty, University of Oulu, Finland.
authors: Katja
authors: K
authors: Jussila
authors: All of the authors are with the Clinic of Child Psychiatry, University and University Hospital of Oulu, Finland, with the exception of Mr. Bloigu, who is with the Medical Faculty, University of Oulu, Finland.
authors: Sirkka-Liisa
authors: SL
authors: Linna
authors: All of the authors are with the Clinic of Child Psychiatry, University and University Hospital of Oulu, Finland, with the exception of Mr. Bloigu, who is with the Medical Faculty, University of Oulu, Finland.
authors: Risto
authors: R
authors: Bloigu
authors: All of the authors are with the Clinic of Child Psychiatry, University and University Hospital of Oulu, Finland, with the exception of Mr. Bloigu, who is with the Medical Faculty, University of Oulu, Finland.
authors: Hanna
authors: H
authors: Ebeling
authors: All of the authors are with the Clinic of Child Psychiatry, University and University Hospital of Oulu, Finland, with the exception of Mr. Bloigu, who is with the Medical Faculty, University of Oulu, Finland.
authors: Irma
authors: I
authors: Moilanen
mesh_terms: D000293:Adolescent; D020817:Asperger Syndrome / Q000175:diagnosis* / Q000453:epidemiology*; D002648:Child; D003937:Diagnosis, Differential; D039721:Diagnostic and Statistical Manual of Mental Disorders; D005260:Female; D006801:Humans; D038801:International Classification of Diseases; D008297:Male; D015995:Prevalence; D011795:Surveys and Questionnaires