title: Prevalence of autism and attention-deficit-hyperactivity disorder in Down syndrome: a population-based study.
abstract: To investigate the prevalence of autism spectrum disorder (ASD) and attention-deficit-hyperactivity disorder (ADHD) in a population-based group of children and adolescents with Down syndrome, and to relate the findings to level of intellectual disability and to medical conditions.
  
  
  
  From a population-based cohort of 60 children and adolescents with Down syndrome, 41 individuals (29 males, 12 females; mean age 11y, age range 5-17y) for whom parents gave consent for participation were clinically assessed with regard to ASD and ADHD. The main instruments used were the Autism Diagnostic Interview-Revised, Autism Diagnostic Observation Schedule, Swanson, Nolan, and Pelham-IV Rating Scale, and the Adaptive Behavior Assessment System-II.
  
  
  
  High rates of ASD and ADHD were found: 17 (42%) and 14 (34%) of the 41 children met DSM criteria for ASD and ADHD respectively.
  
  
  
  Children with Down syndrome and coexisting neurodevelopmental/neuropsychiatric disorders in addition to intellectual disability and medical disorders constitute a severely disabled group. Based on the results, we suggest that screening is implemented for both ASD and ADHD, at the age of 3 to 5 years and early school years respectively, to make adequate interventions possible.
authors: Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
authors: Ulrika Wester
authors: UW
authors: Oxelgren
authors: Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
authors: Åsa
authors: Å
authors: Myrelid
authors: Department of Immunology, Genetics, and Pathology, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
authors: Göran
authors: G
authors: Annerén
authors: Department of Health and Rehabilitation, Kungsgärdet Center, Uppsala, Sweden.
authors: Bodil
authors: B
authors: Ekstam
authors: Department of Health and Rehabilitation, Kungsgärdet Center, Uppsala, Sweden.
authors: Cathrine
authors: C
authors: Göransson
authors: Department of Health and Rehabilitation, Kungsgärdet Center, Uppsala, Sweden.
authors: Agneta
authors: A
authors: Holmbom
authors: Department of Health and Rehabilitation, Kungsgärdet Center, Uppsala, Sweden.
authors: Anne
authors: A
authors: Isaksson
authors: Department of Health and Rehabilitation, Kungsgärdet Center, Uppsala, Sweden.
authors: Marie
authors: M
authors: Åberg
authors: Department of Women's and Children's Health, Uppsala University, Uppsala, Sweden.
authors: Jan
authors: J
authors: Gustafsson
authors: Gillberg Neuropsychiatry Centre, Department of Neuroscience and Physiology, Gothenburg University, Gothenburg, Sweden.
authors: Elisabeth
authors: E
authors: Fernell
mesh_terms: D000293:Adolescent; D001289:Attention Deficit Disorder with Hyperactivity / Q000453:epidemiology* / Q000209:etiology*; D001321:Autistic Disorder / Q000453:epidemiology* / Q000209:etiology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D018672:Community Health Planning; D004314:Down Syndrome / Q000150:complications* / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D009460:Neurologic Examination; D015995:Prevalence; D011569:Psychiatric Status Rating Scales