AIM: To investigate cognitive development in preschool-age children diagnosed with Autistic Spectrum Disorder (ASD; N = 39) compared with that of children diagnosed with mental retardation (MR; N = 14) and normally developing children (NC; N = 36). METHOD: In a prospective longitudinal study, cognitive development was tested at age 24 months (T1; SD = 6 months) and 43 months (T2; SD = 5). RESULTS: Group IQ scores were stable between T1 and T2 as evidenced by high correlations (r = .81, P < .01) and consistency of average group scores. At the same time however, about a third of children with ASD showed an increase of cognitive scores of 15 points or more. This increase of IQ was correlated with lower scores at the early screening of autistic traits (ESAT) at T1, higher IQ level at T2 and higher expressive language skills at T2. Intensity of treatment was not related to IQ increase. CONCLUSIONS: High correlations between cognitive scores in preschool children with ASD suggest that measurements of cognitive function are valid at this age. We found indications of both stability and change of IQ scores. Findings suggest that some children with ASD show catch-up intellectual development. To the best of our knowledge, this increase in IQ scores cannot be attributed to treatment effects.
AIM: To investigate cognitive development in preschool-age children diagnosed with Autistic Spectrum Disorder (ASD; N = 39) compared with that of children diagnosed with mental retardation (MR; N = 14) and normally developing children (NC; N = 36). METHOD: In a prospective longitudinal study, cognitive development was tested at age 24 months (T1; SD = 6 months) and 43 months (T2; SD = 5). RESULTS: Group IQ scores were stable between T1 and T2 as evidenced by high correlations (r = .81, P < .01) and consistency of average group scores. At the same time however, about a third of children with ASD showed an increase of cognitive scores of 15 points or more. This increase of IQ was correlated with lower scores at the early screening of autistic traits (ESAT) at T1, higher IQ level at T2 and higher expressive language skills at T2. Intensity of treatment was not related to IQ increase. CONCLUSIONS: High correlations between cognitive scores in preschool children with ASD suggest that measurements of cognitive function are valid at this age. We found indications of both stability and change of IQ scores. Findings suggest that some children with ASD show catch-up intellectual development. To the best of our knowledge, this increase in IQ scores cannot be attributed to treatment effects.
Authors: P A Filipek; P J Accardo; G T Baranek; E H Cook; G Dawson; B Gordon; J S Gravel; C P Johnson; R J Kallen; S E Levy; N J Minshew; S Ozonoff; B M Prizant; I Rapin; S J Rogers; W L Stone; S Teplin; R F Tuchman; F R Volkmar Journal: J Autism Dev Disord Date: 1999-12
Authors: Helen E Flanagan; Isabel M Smith; Tracy Vaillancourt; Eric Duku; Peter Szatmari; Susan Bryson; Eric Fombonne; Pat Mirenda; Wendy Roberts; Joanne Volden; Charlotte Waddell; Lonnie Zwaigenbaum; Teresa Bennett; Mayada Elsabbagh; Stelios Georgiades Journal: J Autism Dev Disord Date: 2015-09
Authors: Emma van Daalen; Chantal Kemner; Claudine Dietz; Sophie H N Swinkels; Jan K Buitelaar; Herman van Engeland Journal: Eur Child Adolesc Psychiatry Date: 2009-05-07 Impact factor: 4.785
Authors: Jonathan O'Muircheartaigh; Douglas C Dean; Holly Dirks; Nicole Waskiewicz; Katie Lehman; Beth A Jerskey; Sean C L Deoni Journal: J Neurosci Date: 2013-10-09 Impact factor: 6.167
Authors: Clare Harrop; Erin Libsack; Raphael Bernier; Mirella Dapretto; Allison Jack; James C McPartland; John D Van Horn; Sara J Webb; Kevin Pelphrey Journal: Autism Res Date: 2020-12-04 Impact factor: 5.216