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The Changing Prevalence of Autism in California

Abstract

We conducted a population-based study of eight successive California births cohorts to examine the degree to which improvements in detection and changes in diagnosis contribute to the observed increase in autism prevalence. Children born in 1987-1994 who had autism were identified from the statewide agency responsible for coordinating services for individuals with developmental disabilities. To evaluate the role of diagnostic substitution, trends in prevalence of mental retardation without autism were also investigated. A total of 5038 children with full syndrome autism were identified from 4,590,333 California births, a prevalence of 11.0 per 10,000. During the study period, prevalence increased from 5.8 to 14.9 per 10,000, for an absolute change of 9.1 per 10,000. The pattern of increase was not influenced by maternal age, race/ethnicity, education, child gender, or plurality. During the same period, the prevalence of mental retardation without autism decreased from 28.8 to 19.5 per 10,000, for an absolute change of 9.3 per 10,000. These data suggest that improvements in detection and changes in diagnosis account for the observed increase in autism; whether there has also been a true increase in incidence is not known.

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REFERENCES

  1. American Psychiatric Association (1980). Diagnostic and statisticalmanual of mental disorders III. Washington, D.C.: American Psychiatric Association.

    Google Scholar 

  2. American Psychiatric Association (1987). Diagnostic and statistical manual of mental disorders III-R. Washington, D.C.: American Psychiatric Association.

    Google Scholar 

  3. American Psychiatric Association (1994). Diagnostic and statistical manual of mental disorders IV. Washington, D.C.: American Psychiatric Association.

    Google Scholar 

  4. Arvidsson, T., Danielsson, B., Forsberg, P., Gillberg, C., Johansson, M., & Kallgren, G. (1997). Autism in 3 to 6-year-old children in a suburb of Goteburg, Sweden. Autism, 1, 163–173.

    Google Scholar 

  5. Baron-Cohen, S., Allen, J., & Gillberg, C. (1992). Can autism be detected at 18 months? The needle, the haystack, and the CHAT. British Journal of Psychiatry, 161, 839–843.

    Google Scholar 

  6. Baron-Cohen, S., Cox, A., Baird, G., Swettenham, J., Nightingale, N., Morgan, K. et al. (1996). Psychological markers in the detection of autism in infancy in a large population. British Journal of Psychology, 168, 158–163.

    Google Scholar 

  7. Bax, M. (1994). Editorial: Autism. Developmental Medicine and Child Neurology 36, 659–660.

    Google Scholar 

  8. Bohman, M., Bohman, I. L., Björck, P. O., & Sjöholm, E. (1983). Childhood psychosis in a Northern Swedish county: some preliminary findings from an epidemiological survey. In M. H. Schmidt and H. Remschmidt, Epidemiological approaches in child psychiatry II (pp. 163–173). New York: Thieme-Stratton.

    Google Scholar 

  9. Brask, B. H. (1972). A prevalence investigation of childhood psychosis (pp. 145–153). Oslo: Barnespsykiatrisk.

    Google Scholar 

  10. Bryson, S. E., Clark, B. S., & Smith, I. M. (1988). First report of a Canadian epidemiological study of autistic syndromes. Journal of Child Psychology and Psychiatry, 29, 433–445.

    Google Scholar 

  11. Burd, L., Fisher, W., and Kerbeshian, J. (1987). A prevalence study of pervasive developmental disorders in North Dakota. American Academy of Child and Adolescent Psychiatry, 26, 704–710.

    Google Scholar 

  12. Cialdella, P., & Mamelle, N. (1989). An epidemiological study of infantile autism in a French department (Rhone): A research note. Journal of Child Psychology and Psychiatry, 30, 165¶175.

  13. Centers for Disease Control and Prevention. (2000). Prevalence of autism in Brick Township, New Jersey, 1998: Community report. Atlanta: CDC.

    Google Scholar 

  14. Cochran, W. G. (1954). Some methods of strengthening the common chi-square test. Biometrics 10, 417–451.

    Google Scholar 

  15. Cook, E. H. Jr. (1998). Genetics of autism. Mental Retardation & Developmental Disabilities Research Reviews 4, 113–120.

    Google Scholar 

  16. Deb, S., & Prasad, K. B. (1994). The prevalence of autistic disorder among children with learning disabilities. British Journal of Psychiatry, 165, 395–399.

    Google Scholar 

  17. Department of Developmental Services. (1999). Changes in the population of persons with autism and pervasive developmental disorders in California's developmental services system: 1987¶1998. A report to the legislature. Sacramento, CA: Author.

    Google Scholar 

  18. Filipek, P. A., Accardo, P., Baranek, G. T., Cook, E. H. Jr., Dawson, G., Gordon, B., et al. (1999). The screening and diagnosis of autistic spectrum disorders. Journal of Autism and Developmental Disorders, 29, 437–482.

    Google Scholar 

  19. Fombonne, E. (1999). The epidemiology of autism: A review. Psychological Medicine 29, 769–786.

    Google Scholar 

  20. Fombonne, E., & Du Mazaubrun, C. (1992). Prevalence of infantile autism in four French regions. Social Psychiatry and Psychiatric Epidemiology, 27, 203–210.

    Google Scholar 

  21. Fombonne, E., Du Mazaubrun, C., Cans, C., & Grandjean, H. (1997). Autism and associated medical disorders in a french epidemiological survey. Journal of American Academy of Child and Adolescent Psychiatry, 36, 1561–1569.

    Google Scholar 

  22. Gillberg, C. (1984). Infantile autism and other childhood psychoses in a Swedish urban region: Epidemiological aspects. Journal of Child Psychology and Psychiatry, 25, 35–43.

    Google Scholar 

  23. Gillberg, C., Steffenburg, S., & Schaumann, H. (1991). Is autism more common now than ten years ago? British Journal of Psychiatry, 158, 403–409.

    Google Scholar 

  24. Gillberg, C., & Wing, L. (1999). Autism: Not an extremely rare disorder. Acta Psychiatrica Scandinavia, 99, 399–406.

    Google Scholar 

  25. Honda, H., Shimizu, Y., Misumi, K., Niimi, M., & Ohashi, Y. (1996). Cumulative incidence and prevalence of childhood autism in children in Japan. British Journal of Psychology, 169, 228–225.

    Google Scholar 

  26. Hoshino, Y., Kumashiro, H., Yashima, Y., Tachibana, R., & Watanabe, M. (1982). The epidemiological study of autism in Fukushima-ken. Folia Psychiatrica et Neurologica Japonica, 36, 115–124.

    Google Scholar 

  27. Ishii, T., & Takahashi, O. (1982). Epidemiology of autistic children in Toyota City, Japan. Prevalence. Dublin: World Child Psychiatry Conference.

    Google Scholar 

  28. Kadesjo, B., Gillberg, C., & Hagberg, B. (1999). Brief Report: Autism and Asperger syndrome in seven-year-old children: A total population study. Journal of Autism and Developmental Disorders, 29, 327–331.

    Google Scholar 

  29. Kanner, L. (1943). Autistic disturbances of affective contact. Nervous Child, 2, 217–250.

    Google Scholar 

  30. Krug, D. A., Arick, J., & Almond, P. (1980). Behavior checklist for identifying severely handicapped individuals with high levels of autistic behavior. Journal of Child Psychology and Psychiatry, 21, 221–229.

    Google Scholar 

  31. Lotter, V. (1996). Epidemiology of autistic conditions in young children. I. Prevalence. Social Psychiatry 1, 124–137.

    Google Scholar 

  32. Lovaas, O. I. (1987). Behavioral treatment and normal educational and intellectual functioning in young autistic children. Journal of Consulting Clinical Psychology, 55, 3–9.

    Google Scholar 

  33. Magnusson, P., & Saemundsen, E. (2001). Prevalence of autism in Iceland. Journal of Autism and Developmental Disorders, 31, 153–163.

    Google Scholar 

  34. Matsuishi, T., Shiotsuki, M., Yoshimura, K., Shoji, H., Imuta, F., & Yamashita, F. (1987). High prevalence of infantile autism in Kurume City, Japan. Journal of Child Neurology, 2, 268–271.

    Google Scholar 

  35. McCarthy, P., Fitzgerald, M., & Smith, M. A. (1984). Prevalence of childhood autism in Ireland. Irish Medical Journal 77, 129–130.

    Google Scholar 

  36. Nordin, V., & Gillberg, C. (1996). Autism spectrum disorders in children with physical or mental disability or both. 1: Clinical and epidemiological aspects. Developmental Medicine and Child Neurology 38, 297–313.

    Google Scholar 

  37. Ritvo, E. R., Freeman, B. J., Pingree, C., Mason-Brothers, A., Jorde, L. B., Jenson, W. R., et al. (1989). The UCLA-University of Utah epidemiologic survey of autism: Prevalence. American Journal of Psychiatry, 146, 194–199.

    Google Scholar 

  38. Schopler, E., Reichler, R. J., DeVellis R. F., & Daly, K. (1980). Toward objective classification of childhood autism: Childhood Autism Rating Scale (CARS). Journal of Autism and Developmental Disorders, 10, 91–103.

    Google Scholar 

  39. Selvin, S. (1995). Practice biostatistical methods. Belmont, CA: Duxbury Press.

    Google Scholar 

  40. Sponheim, E., & Skjeldal, O. (1998). Autism and related disorders: Epidemiological findings in a Norwegian study using ICD-10 diagnostic criteria. Journal of Autism and Developmental Disorders, 28, 217–227.

    Google Scholar 

  41. Sugiyama, T., & Abe, T. (1989). The prevalence of autism in Nagoya, Japan: A total population study. Journal of Autism and Developmental Disorders 19, 87–96.

    Google Scholar 

  42. Tanoue, Y., Oda, S., Asano, F., & Kawashima, K. (1988). Epidemiology of infantile autism in Southern Ibaraki, Japan: Differences in prevalence in birth cohorts. Journal of Autism and Developmental Disorders 18, 155–166.

    Google Scholar 

  43. Webb, E. V. J., Lobo, S., Hervas, A., Scourfield, J., & Fraser, W. I. (1997). The changing prevalence of autistic disorder in a Welsh health district. Developmental Medicine and Child Neurology, 39, 150–152.

    Google Scholar 

  44. Wignyosumarto, S., Mukhlas, M., & Shirataki, S. (1992). Epidemiological and clinical study of autistic children in Yogyakarta, Indonesia. The Kobe Journal of Medical Sciences, 38, 1–9.

    Google Scholar 

  45. Wing, L. (1997). The autistic spectrum. Lancet, 350, 1761–1766.

    Google Scholar 

  46. Wing, L., & Gould, J. (1979). Severe impairments of social interaction and associated abnormalities in children: Epidemiology and classification. Journal of Autism and Developmental Disorders, 9, 11–29.

    Google Scholar 

  47. Wing, L., Yeates, S., Brierly, L. M., & Gould, J. (1976). The prevalence of early childhood autism: Comparison of administrative and epidemiological studies. Psychological Medicine, 6, 89–100.

    Google Scholar 

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Correspondence to Lisa A. Croen.

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Croen, L.A., Grether, J.K., Hoogstrate, J. et al. The Changing Prevalence of Autism in California. J Autism Dev Disord 32, 207–215 (2002). https://doi.org/10.1023/A:1015453830880

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  • Autistic spectrum disorders
  • epidemiology
  • prevalence
  • mental retardation