First, it is important to appreciate the history of autism and how autism has been diagnosed suggest authors Morton Ann Gernsbacher, Michelle Dawson, and H. Hill Goldsmith. The diagnosis was first coined in the 1940s, but it was not added to the Diagnostic and Statistical Manual of Mental Disorders (DSM) until 1980, and the DSM diagnostic criteria have changed over the years. For example, the 1980 criteria required that an individual have "a pervasive lack of responsiveness to other people;" in contrast, the current 1994 criteria require that an individual demonstrate only "a lack of spontaneous seeking to share achievements with other people" and peer relationships less sophisticated than would be predicted by the individual's developmental level. As another example, the 1980 criterion of "gross deficits in language development" was replaced by the 1994 criterion of difficulty "sustain[ing] a conversation." One purpose of the report is to make the public aware of these less restrictive diagnostic criteria.
Second, although a California study claimed to show that these diagnostic expansions didn't contribute to the increased number of diagnosed California cases from the 1980s to the 1990s, the authors of the Current Directions in Psychological Science article identified a serious flaw in the unpublished California study's reasoning.
Finally, according to the authors, a third reason not to believe in an autism epidemic involves the U.S., Department of Education's annual "child count" data, which are used as supportive evidence of an autism epidemic. What some people fail to realize is that the Department of Education didn't even have a reporting category for autism until the 1991-1992 school year. Therefore, dramatic increases in the number of children served in the public schools under this reporting category would have been expected throughout the 1990s. The authors propose that the "child count" numbers will most likely continue because they still don't match the numbers reported in recent surveys that use more rigorous epidemiological methods.
The report does not dispute the likelihood that more individuals fit current day diagnostic criteria than fit previous diagnostic criteria, or that more individuals are receiving autism diagnoses than before. But given that the diagnostic criteria have been purposely broadened, there is greater public awareness, and epidemiological studies use updated and more consistent definitions and go to greater lengths to identify cases, the authors caution against calling these logical increases an "epidemic."
The report appears in the latest issue of Current Directions in Psychological Science, a journal of the American Psychological Society. Media wishing to receive a PDF of this article please contact firstname.lastname@example.org
Current Directions in Psychological Science publishes concise reviews on the latest advances in theory and research spanning all of scientific psychology and its applications. The American Psychological Society represents psychologists advocating science-based research in the public's interest.
Morton Ann Gernsbacher is a Vilas Research Professor and the Sir Frederic Bartlett Professor at the University of Wisconsin-Madison. She is President-Elect of the American Psychological Society. Michelle Dawson is a Research Associate at the Pervasive Developmental Disorders Specialized Clinic at the University of Montréal. H. Hill Goldsmith is a UW Foundation Fluno Bascom Professor and Leona Tyler Professor at the University of Wisconsin-Madison. Drs. Gernsbacher and Goldsmith are parents of an autistic child, and Ms. Dawson is autistic.
Dr. Gernsbacher is available for questions and interviews.
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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