title: Co-occurring conditions and change in diagnosis in autism spectrum disorders.
abstract: OBJECTIVE
  This study aimed to investigate descriptive characteristics and co-occurring neurodevelopmental and psychiatric conditions in young children, children, and adolescents with a current and consistent or past but not current (PBNC) diagnosis of autism spectrum disorder (ASD) and how such characteristics and conditions may engender a change in diagnosis of an ASD.
  
  
  METHODS
  Cross-sectional data of 1366 children with a parent-reported current or PBNC ASD diagnosis were obtained from the National Survey of Children's Health 2007 data set across 3 developmental stages: young children (aged 3-5 years), children (aged 6-11 years), and adolescents (aged 12-17 years). Multinomial logistic regression was used to examine demographic characteristics and co-occurring conditions that differentiate the groups with a current ASD from groups with a PBNC ASD.
  
  
  RESULTS
  Results indicated the co-occurring conditions that distinguish groups currently diagnosed with an ASD from groups with a PBNC ASD diagnosis. In young children, current moderate/severe learning disability, and current moderate/severe developmental delay; in children, past speech problem, current moderate/severe anxiety, and past hearing problem; and in adolescents, current moderate/severe speech problem, current mild seizure/epilepsy, and past hearing problem.
  
  
  CONCLUSIONS
  These findings suggest that the presence of co-occurring psychiatric and neurodevelopmental conditions are associated with a change in ASD diagnosis. Questions remain as to whether changes in diagnosis of an ASD are due to true etiologic differences or shifts in diagnostic determination.
authors.affiliation: Center for Autism and Developmental Disabilities Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. hclose@jhsph.edu
authors.forename: Heather A
authors.initials: HA
authors.lastname: Close
authors.forename: Li-Ching
authors.initials: LC
authors.lastname: Lee
authors.forename: Christopher N
authors.initials: CN
authors.lastname: Kaufmann
authors.forename: Andrew W
authors.initials: AW
authors.lastname: Zimmerman
mesh_terms: D000293:Adolescent; D002648:Child; D002653:Child Behavior Disorders / Q000175:diagnosis / Q000453:epidemiology; D002659:Child Development Disorders, Pervasive / Q000175:diagnosis* / Q000453:epidemiology*; D002675:Child, Preschool; D015331:Cohort Studies; D015897:Comorbidity; D003430:Cross-Sectional Studies; D002658:Developmental Disabilities / Q000175:diagnosis / Q000453:epidemiology; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D001523:Mental Disorders / Q000139:chemically induced / Q000453:epidemiology