International Meeting for Autism Research (London, May 15-17, 2008): Language and Intellectual Ability Differentially Moderate Outcome in High Functioning Autism and Asperger Syndrome

Saturday, May 17, 2008

Champagne Terrace/Bordeaux (Novotel London West)

9:30 AM

D. O. Black , Pediatrics and Developmental Neuropsychiatry, National Institute of Mental Health, National Institutes of Health, Bethesda, MD

G. L. Wallace , Laboratory of Brain and Cognition, NIMH, Bethesda, MD

L. K. Case , Laboratory of Brain and Cognition, NIMH, Bethesda, MD

J. L. Sokoloff , Center for Autism Spectrum Disorders, Children's National Medical Center, George Washington University, Rockville, MD

J. Strang , Center for Autism Spectrum Disorders, Children's National Medical Center, George Washington University, Rockville, MD

J. A. Silvers , Laboratory of Brain and Cognition, NIMH, Bethesda, MD

L. Kenworthy , Center for Autism Spectrum Disorders, Children's National Medical Center, George Washington University, Rockville, MD

Background:

Intellectual ability and language level have been identified as important factors in autism spectrum disorders (ASD). It remains unclear which of these abilities are most important in moderating symptom severity and outcome in ASD and whether the effects of these variables differ in children with high functioning autism (HFA) versus Asperger syndrome. Further refining how these variables impact symptom presentation and functioning may have implications for treatment priorities

Objectives:

Examine: 1) the influence of verbal knowledge (Vocabulary), nonverbal ability (Block Design), and language impairment (sentence memory) on the presentation of autism symptoms and adaptive functioning in ASD and 2) the effect of these variables by diagnostic group (HFA, Asperger, PDD-NOS).

Methods:

Subjects were a clinically referred sample of 86 school age children (mean age: 9.6±2.8 years; 82% male; verbal or nonverbal IQ ≥75) diagnosed with an ASD based on the Autism Diagnostic Interview, Autism Diagnostic Observation Schedule, and clinical impression. Parents of subjects were interviewed using the Vineland Adaptive Behavior Scale (VABS). Data were analyzed using partial correlations, controlling for age.

Results:

For the whole sample, Vocabulary was related to autism communication symptoms (pr=-.26), VABS Communication (pr=.65) and VABS Daily Living Skills (pr=.29). Sentence memory was related to VABS Communication (pr=.54) and VABS Daily Living Skills (pr=.28). Block Design was only related to VABS Communication (pr=.34). No language or nonverbal ability measure was significantly related to autism social symptoms, autism restricted/repetitive behaviors, or VABS Socialization. This pattern of results held for the HFA and PDD-NOS groups, but none of the cognitive or language variables were related to autism symptoms or adaptive functioning within the Asperger syndrome group.

Conclusions:

We find that better cognitive and language abilities support adaptive functioning and reduce the severity of autism communication symptoms among individuals with HFA and PDD-NOS but not those with Asperger syndrome.

See more of: Clinical Phenotype Posters 2
See more of: Poster Presentations