Journal of Autism and Developmental Disorders

, Volume 47, Issue 9, pp 2733–2742 | Cite as

Diagnostic Substitution for Intellectual Disability: A Flawed Explanation for the Rise in Autism

  • Cynthia D. NevisonEmail author
  • Mark Blaxill
Original Paper


Time trends in autism spectrum disorder (ASD) and intellectual disability (ID) prevalence from the United States Individuals with Disabilities Education Act data were computed from 2000 to 2011 for each state and each age from 6 to 17. These trends did not support the hypothesis that diagnostic substitution for ID can explain the ASD rise over recent decades, although the hypothesis appeared more plausible when the data were aggregated across all states and ages. Nationwide ID prevalence declined steeply over the last two decades, but the decline was driven mainly by ~15 states accounting for only one-fourth of the U.S. school population. More commonly, including in the most populous states, ID prevalence stayed relatively constant while ASD prevalence rose sharply.


Autism spectrum disorder (ASD) Mental retardation Intellectual disability Diagnostic substitution Time trends Individuals with Disabilities Education Act (IDEA) 



We thank the Individuals with Disabilities Education Act for providing the data used in this study.


CN and MB did not have specific funding for this work.

Author’s Contributions

CN compiled the IDEA data, performed all calculations and wrote the Methods and Results. MB conceived of the study and wrote the Introduction and Discussion.

Compliance with Ethical Standards

Conflict of interest

CN and MB declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Ethical Approval

The ASD and MR counts used in this study involved datasets in which all relevant personal information had been de-identified prior to our activities and in which the data were aggregated by age at the state level. This project therefore did not require institutional review and approval.

Supplementary material

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Supplementary material 1 Figure S1 (DOCX 594 KB)
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Supplementary material 2 Figure S2 (DOCX 467 KB)
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Supplementary material 3 Figure S3 (DOCX 232 KB)
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Supplementary material 4 Figure S4 (DOCX 248 KB)
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Supplementary material 5 Figure S5 (DOCX 574 KB)
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Supplementary material 6 ASD counts (XLSX 147 KB)
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Supplementary material 7 ID counts (XLSX 113 KB)
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Supplementary material 8 SLD counts (XLSX 141 KB)
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Supplementary material 9 DD counts (XLSX 143 KB)
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Supplementary material 10 OHI counts (XLSX 148 KB)
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Supplementary material 11 NCES school populations (XLSX 160 KB)


  1. American Psychiatric Association. (1994). Diagnostic and statistical manual of mental disorders (DSM-4). Washington, D.C.: American Psychiatric Association.Google Scholar
  2. American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (DSM-5). Washington, D.C.: American Psychiatric Association.CrossRefGoogle Scholar
  3. Bertrand, J., Mars, A., Boyle, C., Bove, F., Yeargin-Allsopp, M., & Decoufle, P. (2001). Prevalence of autism in a United States population: The Brick Township, New Jersey, investigation. Pediatrics, 108(5), 1155–1161. doi: 10.1542/peds.108.5.1155.CrossRefPubMedGoogle Scholar
  4. Blaxill, M. F. (2004). What’s going on? The question of time trends in autism. Public Health Reports, 119(6), 536–551. doi: 10.1016/j.phr.2004.09.003.CrossRefPubMedPubMedCentralGoogle Scholar
  5. Blaxill, M. F., Baskin, D. S., & Spitzer, W. O. (2003). Commentary: Blaxill, Baskin, and Spitzer on Croen et al. (2002), the changing prevalence of autism in California. Journal of autism and developmental disorders, 33,(2), 223–226.
  6. Burd, L., Fisher, W., & Kerbeshian, J. (1987). A prevalence study of pervasive developmental disorders in North Dakota. Journal of the American Academy of Child and Adolescent Psychiatry, 26, 700–703.CrossRefPubMedGoogle Scholar
  7. California Department of Developmental Services. (1999). Changes in the population of persons with autism and pervasive developmental disorders in California’s developmental services system: 1987 through 1998: A report to the Legislature. Sacramento, CA.Google Scholar
  8. Centers for Disease Control and Prevention. (2007). Prevalence of autism spectrum disorders: Autism and developmental disabilities monitoring network, six sites, United States, 2000. Morbidity and Mortality Weekly Report, 56(SS01), 1–11.
  9. Centers for Disease Control and Prevention. (2014). Prevalence of autism spectrum disorder among children aged 8 years: Autism and developmental disabilities monitoring network, 11 sites, United States, 2010. Morbidity and mortality weekly report, 63(Suppl 2), 1–21.
  10. Centers for Disease Control and Prevention. (2016). Prevalence and characteristics of autism spectrum disorder among children aged 8 years—Autism and developmental disabilities monitoring network, 11 sites, United States, 2012. MMWR Surveillance Summaries, 65(3), 1–23.CrossRefGoogle Scholar
  11. Cortiella, C., & Horowitz, S. H. (2014). The State of Learning Disabilities: Facts, trends and emerging issues. New York: National Center for Learning Disabilities.Google Scholar
  12. Croen, L., & Grether, J. K. (2003). Response: A response to Blaxill, Baskin, and Spitzer on Croen et al. (2002), ‘The changing prevalence of autism in California. Journal of autism and developmental disorders, 33(2), 227–229.
  13. Croen, L., Grether, J. K., Hoogstrate, J., & Selvin, S. (2002). The changing prevalence of autism in California. Journal of Autism & Developmental Disorders, 32(3), 207–215.CrossRefGoogle Scholar
  14. Fombonne, E. (1998). Epidemiological surveys of autism. In F. R. Volkmar (Ed.), Autism and pervasive developmental disorders 32–63. Cambridge: Cambridge University Press.Google Scholar
  15. Gurney, J. G., Fritz, M. S., Ness, K. K., Sievers, P., Newschaffer, C. J., Shapiro, E.G (2003). Analysis of prevalence trends of autism spectrum disorder in Minnesota. Archives of Pediatrics & Adolescent Medicine, 157, 622–627. doi: 10.1001/archpedi.157.7.622.CrossRefGoogle Scholar
  16. Individuals with Disabilities Education Act (IDEA). (2004). Accessed March 17, 2017.
  17. Jick, H., & Kaye, J. A. (2003). Epidemiology and Possible causes of autism. Pharmacotherapy, 23(12), 1524–1530.CrossRefPubMedGoogle Scholar
  18. Kanner, L. (1943). Autistic disturbances of affective contact. Nervous Child, 2, 217–250Google Scholar
  19. MacFarlane, J. R., & Kanaya, T. (2009). What does it mean to be autistic? Inter-state variation in special education criteria for autism services. Journal of Child and Family Studies. doi: 10.1007/s10826-009-9268-8.Google Scholar
  20. McDonald, M. E., & Paul, J. F. (2010). Timing of increased autistic disorder cumulative incidence. Environmental Science and Technology, 44(6), 2112–2118. doi: 10.1021/es902057k.CrossRefPubMedGoogle Scholar
  21. Nevin, R. (2009). Trends in preschool lead exposure, mental retardation, and scholastic achievement: Association or causation? Environmental Research, 109, 301–310. doi: 10.1016/j.envres.2008.12.003.CrossRefPubMedGoogle Scholar
  22. Nevison, C. D. (2014). A comparison of temporal trends in United States autism prevalence to trends in suspected environmental factors. Environmental Health, 13(1), 73. doi: 10.1186/1476-069X-13-73.CrossRefPubMedPubMedCentralGoogle Scholar
  23. Newschaffer, C. J., Falb, M. D., & Gurney, J. G. (2007). National autism prevalence trends from United States special education data. Pediatrics, 115(3), e277–e282. doi: 10.1542/peds.2004-1958.CrossRefGoogle Scholar
  24. Polyak, A., Kubina, R. M., & Girirajan, S. (2015). Comorbidity of intellectual disability confounds ascertainment of autism: implications for genetic diagnosis. American Journal of Medical Genetics Part B, 168(7), 600–608. doi: 10.1002/ajmg.b.32338.CrossRefGoogle Scholar
  25. Ritvo, E. R., Freeman, B. J., Pingree, C., Mason-Brothers, A., Jorde, L., & Jenson, W. R. (1989). The UCLA-University of Utah epidemiologic survey of autism: prevalence. American Journal of Psychiatry, 146, 194–199.CrossRefPubMedGoogle Scholar
  26. Shattuck, P. T. (2006). The contribution of diagnostic substitution to the growing administrative prevalence of autism in US special education. Pediatrics, 117(4), 1028–1037. doi: 10.1542/peds.2005-1516.CrossRefPubMedGoogle Scholar
  27. Treffert, D. A. (1970). Epidemiology of infantile autism. Archives of General Psychiatry, 22, 431–438.CrossRefPubMedGoogle Scholar
  28. Van Naarden Braun, K., Christensen, D., Doernberg, N., Schieve, L., Rice, C., Wiggins, L., Schendel, D., & Yeargin-Allsopp, M. (2015). Trends in the prevalence of autism spectrum disorder, cerebral palsy, hearing loss, intellectual disability, and vision impairment, metropolitan Atlanta, 1991–2010. PLoS ONE, 10(4), 1–21. doi: 10.1371/journal.pone.0124120.Google Scholar
  29. Walpole, R. E., & Myers, R. H. (1985). Probability and statistics for Engineers and Scientists. New York: Macmillan.Google Scholar
  30. Wing, L. (1993). The definition and prevalence of autism: a review. European Child and Adolescent Psychiatry, 2, 61–74.
  31. Yeargin-Allsopp, M., Rice, C., Karapurkar, T., Doernbert, N., Boyle, C., & Murphy, C. (2003). Prevalence of autism in a U.S. metropolitan area. JAMA, 289, 49–55.CrossRefPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2017

Authors and Affiliations

  1. 1.Institute for Arctic and Alpine ResearchUniversity of ColoradoBoulderUSA
  2. 2.Health ChoiceCambridgeUSA

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