Skip to main content

Evaluating Changes in the Prevalence of the Autism Spectrum Disorders (ASDs)


Autism spectrum disorders (ASDs) are estimated to occur among about one percent of children in the United States. This estimate is in line with estimates from other industrialized countries. However, the identified prevalence of ASDs has increased significantly in a short time period based on data from multiple studies including the U.S. Centers for Disease Control and Prevention’s (CDC) Autism and Developmental Disabilities Monitoring (ADDM) Network. Whether increases in ASD prevalence are partly attributable to a true increase in the risk of developing ASD or solely to changes in community awareness and identification patterns is not known. It is clear that more children are identified with an ASD now than in the past and the impact on individuals, families, and communities is significant. However, disentangling the many potential reasons for ASD prevalence increases has been challenging. Understanding the relative contribution of multiple factors such as variation in study methods, changes in diagnostic and community identification, and potential changes in risk factors is an important priority for the ADDM Network and for CDC. This article summarizes the discussion from a workshop that was co-sponsored by CDC and Autism Speaks as a forum for sharing knowledge and opinions of a diverse range of stakeholders about changes in ASD prevalence. Panelists discussed recommendations for building on existing infrastructure and developing new initiatives to better understand ASD trends. The information, research, and opinions shared during this workshop add to the knowledge base about ASD prevalence in an effort to stimulate further work to understand the multiple reasons behind increasing ASD prevalence.


  1. 1.

    American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, 4th Edition, Text Revision (DSM-IVTR). Washington, DC: American Psychiatric Publishing; 2000.

    Book  Google Scholar 

  2. 2.

    Volkmar FR, Paul R, Klin A, Cohen D (editors). Handbook of Autism and Pervasive Developmental Disorders, Vol. 1: Diagnosis, Development, Neurobiology, and Behavior (3rd ed.). Hoboken NJ: John Wiley & Sons Inc; 2005.

    Google Scholar 

  3. 3.

    Levy S, Giarelli E, Lee L, Schieve L, Kirby R, et al. Autism spectrum disorders and co-occurring developmental, psychiatric, and medical conditions among children in multiple populations of the United States. J Dev Behav Pediatr.2010;31:267–75.

    Article  PubMed  Google Scholar 

  4. 4.

    Centers for Disease Control and Prevention. Prevalence of autism spectrum disorders - autism and developmental disabilities monitoring network, 14 sites, United States, 2008. MMWR Surveill Summ. 2012;61:1–19.

    Google Scholar 

  5. 5.

    Abrahams B, Geschwind D. Advances in autism genetics: on the threshold of a new neurobiology. Nat Rev Genet. 2008;9:341–55.

    CAS  Article  PubMed  PubMed Central  Google Scholar 

  6. 6.

    Lichtenstein P, Carlström E, Råstam M, Gillberg C, Anckarsäter H. The genetics of autism spectrum disorders and related neuropsychiatric disorders in childhood. Am J Psychiatry. 2010;167:1357–63.

    Article  PubMed  Google Scholar 

  7. 7.

    Daniels JL. Autism and the environment. Environ Health Perspect. 2006;114:A396.

    Article  PubMed  PubMed Central  Google Scholar 

  8. 8.

    Workshop on US data to evaluate changes in the prevalence of autism spectrum disorders. February 1, 2011, Atlanta, Georgia, U.S. Available from URL: (Accessed 12 July 2012).

  9. 9.

    Newschaffer C, Croen L, Daniels J, Giarelli E, Grether J, et. al. The epidemiology of the autism spectrum disorders. Annu Rev Public Health. 2007; 28:235–58.

    Article  PubMed  Google Scholar 

  10. 10.

    Rice C. Time trends in diagnosis. In: Volkmar F (Editor). Encyclopedia of Autism Spectrum Disorders. Springer; In press.

  11. 11.

    Fombonne E. Epidemiology of pervasive developmental disorders. Pediatr Res. 2009;65:591–8.

    Article  PubMed  Google Scholar 

  12. 12.

    Cavagnaro, A. Autistic spectrum disorders changes in the California caseload an update: June 1987-June 2007. California Department of Developmental Services. 2009;19:536–51.

    Google Scholar 

  13. 13.

    Newschaffer C, Falb M, Gurney J. National autism prevalence trends from United States special education data. Pediatrics. 2005; 115: 277–82.

    Article  Google Scholar 

  14. 14.

    Bertrand J, Mars A, Boyle C, Bove F, Yeargin-Allsopp M, Decoufle P. Prevalence of autism in a United States population: the Brick Township, New Jersey, investigation. Pediatrics. 2001;108:1155–61.

    CAS  Article  PubMed  Google Scholar 

  15. 15.

    Yeargin-Allsopp M, Rice C, Karapurkar T, Doernberg N, Boyle C, Murphy C. Prevalence of autism in a US metropolitan area. JAMA 2003;289:49–55.

    Article  PubMed  Google Scholar 

  16. 16.

    Centers for Disease Control and Prevention. Prevalence of autism spectrum disorders - autism and developmental disabilities monitoring network, united states, 2006. MMWR Surveill Summ. 2009;58:1–20.

    Google Scholar 

  17. 17.

    Hertz-Picciotto I, Delwiche L. The rise in autism and the role of age at diagnosis. Epidemiology. 2009;20:84–90.

    Article  PubMed  PubMed Central  Google Scholar 

  18. 18.

    King M, Bearman P. Diagnostic change and the increased prevalence of autism. Int J Epidemiol. 2009;38:1224–34. (Commentaries by Charman, Formbonne, Hertz-Picciotto, Rutter, and response).

    Article  PubMed  PubMed Central  Google Scholar 

  19. 19.

    Baird G, Simonoff E, Pickles A, Chandler S, Loucas T, et al. Prevalence of disorders of the autism spectrum in a population cohort of children in South Thames: the special needs and autism project (SNAP). Lancet. 2006;368:210–5.

    Article  PubMed  Google Scholar 

  20. 20.

    Baron-Cohen S, Scott F, Allison C, Williams J, Bolton P, et al. Prevalence of autism spectrum conditions: UK school-based population study. Br J Psychiatry. 2009;194:500–9.

    Google Scholar 

  21. 21.

    Brugha TS, McManus S, Bankart J, Scott F, Purdon S, et al. Epidemiology of autism spectrum disorders in adults in the community in England. Arch Gen Psychiatry. 2011;68:459–65.

    Article  PubMed  Google Scholar 

  22. 22.

    Honda H, Shimizu Y, Rutter M. No effect of MMR withdrawal on the incidence of autism: a total population study. J Child Psychol Psychiatry. 2005; 46:572–9.

    Article  PubMed  Google Scholar 

  23. 23.

    Kadesjö B, Gillberg C, Hagberg B. Brief report: autism and asperger syndrome in seven-year-old children: a total population study. J Autism Dev Disord. 1999;29:327–31.

    Article  PubMed  Google Scholar 

  24. 24.

    Kogan M, Blumberg S, Schieve L, Boyle C, Perrin J, et al. Prevalence of parent-reported diagnosis of autism spectrum disorder among children in the U.S., 2007. Pediatrics. 2009;124:1395–403.

    Article  PubMed  Google Scholar 

  25. 25.

    Society for Research in Child Development (SRCD). Social policy report on the autism spectrum disorders. SRCD Social Policy Report. 2010:24(2).

  26. 26.

    Rutter M. Incidence of autism spectrum disorders: changes over time and their meaning. Acta Paediatr. 2005;94:2–15.

    CAS  Article  PubMed  Google Scholar 

  27. 27.

    Individuals with Disabilities Education Act (IDEA) Data. Washington, DC: U.S. Department of Education, Office of Special Education Programs; 2009. Number of children served under IDEA by disability and age group through 2007. Available from URL: (Accessed 26 February 2013).

    Google Scholar 

  28. 28.

    Shelton J, Tancredi D, Hertz-Picciotto I. Independent and dependent contributions of advanced maternal and paternal ages to autism risk. Autism Res. 2010;3:30–9.

    Article  PubMed  PubMed Central  Google Scholar 

  29. 29.

    Van Meter K, Christiansen L, Delwiche L, Azari R, Carpenter T, Hertz-Picciotto I Geographic distribution of autism in California: a retrospective birth cohort analysis. Autism Res. 2010;3:19–29.

    PubMed  PubMed Central  Google Scholar 

  30. 30.

    Liu K, King M, Bearman P. Social influence and the autism epidemic. AJS. 2010;115:1387–434.

    PubMed  PubMed Central  Google Scholar 

  31. 31.

    Cheslack-Postava K, Liu K, Bearman PS. Closely spaced pregnancies are associated with increased odds of autism in California sibling births. Pediatrics. 2011;127:246–53.

    Article  PubMed  PubMed Central  Google Scholar 

  32. 32.

    Fountain C, King MD, Bearman PS. Age of diagnosis for autism: individual and community factors across 10 birth cohorts. J Epidemiol Community Health. 2011;65:503–10.

    Article  PubMed  Google Scholar 

  33. 33.

    Keyes KM, Susser E, Cheslack-Postava K, Fountain C, Liu K, Bearman PS. Cohort effects explain the increase in autism diagnosis among children born from 1992 to 2003 in California. Int J Epidemiol. 2012;41:495–503.

    Article  PubMed  Google Scholar 

  34. 34.

    Kim YS, Leventhal B., Koh Y., Fombonne E, Laska E, et al. Prevalence of autism spectrum disorders in a total population sample. Am J Psychiatry. 2011;168:904–12.

    Article  PubMed  Google Scholar 

  35. 35.

    Roelfsema MT, Hoekstra RA, Allison C, Wheelwright S, Brayne C, et al. Are autism spectrum conditions more prevalent in an information-technology region? A school-based study of three regions in the Netherlands. J Autism Dev Disord. 2012;42:734–9.

    Article  PubMed  Google Scholar 

  36. 36.

    Rice C, Nicholas J, Baio J, Pettygrove S, Lee L, et. al. Changes in autism spectrum disorder prevalence in 4 areas of the United States. Disabil Health J. 2010;3:186–201.

    Article  PubMed  Google Scholar 

  37. 37.

    Durkin M, Maenner M, Newschaffer C, Lee L, Cunniff C, et al. Advanced parental age and the risk of autism spectrum disorder. Am J Epidemiol. 2008;168:1268–76.

    Article  PubMed  PubMed Central  Google Scholar 

  38. 38.

    Van Naarden Braun K, Schieve L, Daniels J, Durkin M, Giarelli E, et al. Relationships between multiple births and autism spectrum disorders, cerebral palsy, and intellectual disabilities: autism and developmental disabilities monitoring (ADDM) network-2002 surveillance year. Autism Res. 2008;1:265–316.

    Article  Google Scholar 

  39. 39.

    Durkin M, Maenner M, Meaney F, Levy S, Diguiseppi C, et. al. Socioeconomic inequality in the prevalence of autism spectrum disorder: evidence from a U.S. cross-sectional study. PLoS One. 2010;5:e11551.

    Article  PubMed  PubMed Central  Google Scholar 

  40. 40.

    Kalkbrenner A, Daniels J, Chen J, Poole C, Emch M, Morrissey J. Perinatal exposure to hazardous air pollutants and autism spectrum disorders at age 8. Epidemiology. 2010;21:631–41.

    Article  PubMed  PubMed Central  Google Scholar 

  41. 41.

    Shattuck PT, Durkin M, Maenner M, Newschaffer C, Mandell DS, et al. Timing of identification among children with an autism spectrum disorder: findings from a population-based surveillance study. J Am Acad Child Adolesc Psychiatry. 2009;48:474–83.

    Article  PubMed  PubMed Central  Google Scholar 

  42. 42.

    Kolevzon A, Gross R, Reichenberg A. Prenatal and perinatal risk factors for autism: a review and integration of findings. Arch Pediatr Adolesc Med. 2007;161:326–33.

    Article  PubMed  Google Scholar 

  43. 43.

    Ward EM, Thun MJ, Hannan LM, Jemal A. Interpreting cancer trends. Ann N Y Acad Sci. 2006;1076:29–53.

    Article  PubMed  Google Scholar 

  44. 44.

    Wingo PA, Jamison PM, Hiatt RA, Weir HK, Gargiullo PM, et al. Building the infrastructure for nationwide cancer surveillance and control—a comparison between the National Program of Cancer Registries (NPCR) and the Surveillance, Epidemiology, and End Results (SEER) Program (United States). Cancer Causes Control. 2003;14:175–93.

    Article  PubMed  Google Scholar 

  45. 45.

    Jemal A, Center MM, DeSantis C, Ward EM. Global patterns of cancer incidence and mortality rates and trends. Cancer Epidemiol Biomarkers Prev. 2010;19:1893–907.

    Article  PubMed  Google Scholar 

  46. 46.

    Cancer Intervention and Surveillance Modeling Network (CISNET). National Cancer Institute, U.S. National Institutes of Health. Bethesda, MD. Available from URL: (Accessed 26 February 2013).

    Google Scholar 

  47. 47.

    Twelves D, Perkins KS, Counsell C. Systematic review of incidence studies of Parkinson’s disease. Mov Disord. 2003;18:19–31.

    Article  PubMed  Google Scholar 

  48. 48.

    Van Den Eeden S, Tanner C, Bernstein A, Fross R, Leimpeter A, et. al. Incidence of Parkinson’s disease: variation by age, gender, and race/ethnicity. Am J Epidemiol. 2003;157:1015–22.

    Article  Google Scholar 

  49. 49.

    California Parkinson’s Disease Registry (CPDR). Available from URL: (Accessed 26 February 2013).

  50. 50.

    Atladóttir H, Parner E, Schendel D, Dalsgaard S, Thomsen P, Thorsen P. Time trends in reported diagnoses of childhood neuropsychiatric disorders: a Danish cohort study. Arch Pediatr Adolesc Med. 2007;161:193–8.

    Article  PubMed  Google Scholar 

  51. 51.

    Boyle CA, Boulet S, Schieve LA, Cohen RA, Blumberg SJ, et al. Trends in the prevalence of developmental disabilities in US children, 1997–2008. Pediatrics. 2011;127:1034–42.

    Article  PubMed  Google Scholar 

  52. 52.

    Demir A, Celikel S, Karakaya G, Kalyonco A. Asthma and allergic diseases in school children from 1992 to 2007 with incidence data. J Asthma. 2010;47:1128–35.

    Article  PubMed  Google Scholar 

  53. 53.

    World Health Organization. Schizophrenia and public health. Division of Mental Health and Prevention of Substance Abuse, WHO: Geneva, Switzerland; 1998. Available from (Accessed 26 February 2013).

    Google Scholar 

  54. 54.

    McGrath JJ, Susser ES. New directions in the epidemiology of schizophrenia. Med J Aust. 2009;190:S7–9.

    PubMed  Google Scholar 

  55. 55.

    Myers NL. Update: schizophrenia across cultures. Curr Psychiatry Rep. 2011;13:305–11.

    Article  PubMed  Google Scholar 

  56. 56.

    Galea S, Hall C, Kaplan G. Social epidemiology and complex system dynamic modeling as applied to health behaviour and drug use research. Int J Drug Policy. 2009;20:209–16.

    Article  PubMed  Google Scholar 

  57. 57.

    Galea S, Riddle M, Kaplan G. Casual thinking and complex system approaches in epidemiology. Int J Epidemiol. 2010;39:97–106.

    Article  PubMed  Google Scholar 

  58. 58.

    Schieve LA, Rice C, Devine O, Maenner MJ, Lee LC, et al. Have secular changes in perinatal risk factors contributed to the recent autism prevalence increase? Development and application of a mathematical assessment model. Ann Epidemiol. 2011;21:930–45.

    Article  PubMed  PubMed Central  Google Scholar 

  59. 59.

    Weintraub K. The prevalence puzzle: autism counts. Nature. 2011;479:22–4.

    CAS  Article  PubMed  Google Scholar 

  60. 60.

    Schwartz S, Susser E. Commentary: what can epidemiology accomplish? Int J Epidemiol. 2006;35:587–90; Discussion 593–6.

    Article  PubMed  Google Scholar 

  61. 61.

    Institute of Medicine of the National Academies. Autism and the Environment: Challenges and Opportunities for Research. Workshop Proceedings. Washington, DC: The National Academies Press; 2007. Available from URL:

    Google Scholar 

  62. 62.

    Rutter ML Progress in understanding autism: 2007–2010. J Autism Dev Disord. 2011;41:395–404.

    Article  PubMed  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Catherine E. Rice PhD.

Rights and permissions

Open Access  This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made.

The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder.

To view a copy of this licence, visit

The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and Permissions

About this article

Cite this article

Rice, C.E., Rosanoff, M., Dawson, G. et al. Evaluating Changes in the Prevalence of the Autism Spectrum Disorders (ASDs). Public Health Rev 34, 17 (2012).

Download citation

Key Words

  • Autism
  • autism spectrum disorders
  • ASD
  • prevalence
  • occurrence