Elsevier

Research in Autism Spectrum Disorders

Volume 2, Issue 3, July–September 2008, Pages 546-556
Research in Autism Spectrum Disorders

Parental reports on the prevalence of co-occurring intellectual disability among children with autism spectrum disorders

https://doi.org/10.1016/j.rasd.2007.11.002Get rights and content

Abstract

Limited evidence suggests that the prevalence of mental retardation (MR) – now called “intellectual disability” (ID) – in ASD ranges between 25.8% and 58.5%, with co-occurrence in 66–70% of children who meet strict criteria for autism. However, parents and professionals differ significantly in their understanding of or opinions about intellectual functioning among children with ASD. The current study analyzed archival data to calculate the prevalence of parent-reported MR among children with ASD (N = 498). Collectively, 9.2% of families affirmed MR; when analyzed by type of ASD, the rates for those with autism and PDD-NOS were 12.6% and 7.3%, respectively. A variety of explanations for these low rates are posited alongside implications for clinical practice and families’ receipt of services.

Section snippets

Participants

Participants were 498 parents and other caregivers of children with ASD.1 Most of them were mothers of focal children (88.8%); the rest were fathers (7.2%), stepmothers (1.0%),

Results

Among the entire sample, 46 families (9.2%) indicated that their children had MR. The prevalence was highest among those with an autism diagnosis (12.6%), followed by PDD-NOS (7.3%), then Asperger's disorder (1.7%). These numbers were significantly different among ASD diagnoses, as can be seen in Table 2. Frequencies of additional diagnoses within each ASD-diagnostic category are also provided. With the exception of MR, ADD/ADHD was the only other diagnosis that was reported at significantly

Discussion

The purpose of the current study was to determine how many parents of children with ASD would espouse MR – now referred to as ID – as an additional diagnosis for their children. Parents in the current sample reported an extremely low frequency of ID: 9.2% compared with recent clinical estimates ranging from 33.1% to 58.5% (ADDM, 2007). When children were grouped by type of ASD diagnosis, the prevalence of ID was greatest among those with autism—12.6%; however, this figure is still remarkably

References (36)

  • D.J. Cottrell et al.

    Communicating an evolutionary diagnosis of disability to parents

    Child: Care, Health, and Development

    (1990)
  • M.G. Edelson

    Are the majority of children with autism mentally retarded? A systematic evaluation of the data

    Focus on Autism and Other Developmental Disabilities

    (2006)
  • W.M.L. Finley et al.

    Rejecting the label: a social constructionist analysis

    Mental Retardation

    (2005)
  • R.C. Fraley

    How to conduct behavioral research over the internet: A beginner's guide to HTML and CGI/Perl

    (2004)
  • D.M. Geiger et al.

    Parent and professional agreement on cognitive level of children with autism

    Journal of Autism and Developmental Disorders

    (2002)
  • R.P. Goin-Kochel et al.

    Congenital vs. regressive onset of autism spectrum disorders: Parents’ beliefs about causes

    Focus on Autism and Other Developmental Disabilities

    (2005)
  • S.D. Gosling et al.

    Should we trust web-based studies?: A comparative analysis of six preconceptions about internet questionnaires

    American Psychologist

    (2004)
  • D.H. Granello et al.

    Online data collection: Strategies for research

    Journal of Counseling and Development

    (2004)
  • Cited by (0)

    This paper was based on data collected as part of the first author's doctoral dissertation.

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