title: Stability and Change in the Cognitive and Adaptive Behaviour Scores of Preschoolers with Autism Spectrum Disorder.
abstract: We examined the stability of cognitive and adaptive behaviour standard scores in children with autism spectrum disorder (ASD) between diagnosis and school entry approximately age 6. IQ increased 18 points in 2-year-olds, 12 points in 3-year-olds, and 9 points in 4-year-olds (N = 281). Adaptive behaviour scores increased 4 points across age groups (N = 289). At school entry, 24 % of children met criteria for intellectual disability (cognitive and adaptive behaviour scores <70). No children with both scores ≥70 at diagnosis later met criteria for intellectual disability. Outcomes were more variable for children with initial delays in both areas (in 57 %, both scores remained <70). Findings are relevant to clinical decision-making, including specification of intellectual disability in young children with ASD.
authors.affiliation: IWK Health Centre, 5980 University Avenue, Halifax, NS, B3K 6R8, Canada, helen.flanagan@iwk.nshealth.ca.
authors.forename: Helen E
authors.initials: HE
authors.lastname: Flanagan
authors.forename: Isabel M
authors.initials: IM
authors.lastname: Smith
authors.forename: Tracy
authors.initials: T
authors.lastname: Vaillancourt
authors.forename: Eric
authors.initials: E
authors.lastname: Duku
authors.forename: Peter
authors.initials: P
authors.lastname: Szatmari
authors.forename: Susan
authors.initials: S
authors.lastname: Bryson
authors.forename: Eric
authors.initials: E
authors.lastname: Fombonne
authors.forename: Pat
authors.initials: P
authors.lastname: Mirenda
authors.forename: Wendy
authors.initials: W
authors.lastname: Roberts
authors.forename: Joanne
authors.initials: J
authors.lastname: Volden
authors.forename: Charlotte
authors.initials: C
authors.lastname: Waddell
authors.forename: Lonnie
authors.initials: L
authors.lastname: Zwaigenbaum
authors.forename: Teresa
authors.initials: T
authors.lastname: Bennett
authors.forename: Mayada
authors.initials: M
authors.lastname: Elsabbagh
authors.forename: Stelios
authors.initials: S
authors.lastname: Georgiades
mesh_terms: D000223:Adaptation, Psychological; D000067877:Autism Spectrum Disorder / Q000523:psychology*; D002648:Child; D002675:Child, Preschool; D003071:Cognition; D005260:Female; D006801:Humans; D008297:Male
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