EBD Blog

To be sure, the number of children identified as having Autism in US schools has risen dramatically and estimates of prevalence have been revised upwards, but there are good reasons to doubt the oft-repeated assertion that the number of cases of Autism is increasing. Writing in Time magazine for 12 January 2007, Claudia Wallis reported that changes in diagnostic criteria, school policies, public perceptions, and other factors Autism are probably the source of the misperception that Autism is increasing at epidemic proportions.

Ms. Wallis depends heavily on a new book by Roy Richard Grinker, Unstrange Minds: Remapping the World of Autism. Professor Grinker, who is an anthropologist teaching at George Washington University (DC, US) as well as the parent of a child with Autism, argued that socio-political factors account for the growth in prevalence.

BROADER DEFINITIONS Each successive edition of the Diagnostic and Statistical Manual of Mental Disorders–the bible of mental health–has revised the criteria for identifying autism in ways that tend to include more people. Two conditions on the milder end of the autistic spectrum–Asperger’s syndrome and the awkwardly named PDD-NOS (pervasive developmental disorder, not otherwise specified)–were added to the DSM in 1994 and 1987, respectively. Grinker and others say 50% to 75% of the increase in diagnoses is coming in these milder categories.

SCHOOL POLICY U.S. schools are required to report data on kids who receive special-education services, but autism wasn’t added as a category until the 1991-92 school year. No wonder the numbers exploded–from 22,445 receiving services for autism in 1995 to 140,254 in 2004. Grinker points out that “traumatic brain injury” also became one of the 13 reportable categories in 1992, and it had a similar spike.

MORE HELP, LESS STIGMA As services have become more available for kids with autism, more parents are seeking a diagnosis they would have shunned 30 years ago, when psychiatrists still blamed autism on chilly “refrigerator” mothers. Doctors are also more willing to apply the diagnosis to help a patient. “I’ll call a kid a zebra if it will get him the educational services I think he needs,” National Institute of Mental Health psychiatrist Judith Rapoport told Grinker.

FINANCIAL INCENTIVES In some states, parents of children with autism can apply for Medicaid even if they are not near the poverty line. A diagnosis of mental retardation doesn’t always offer this advantage.

RELABELING For all the reasons above, many kids previously given other diagnoses are now called autistic. University of Wisconsin researcher Paul Shattuck has found that the number of kids getting special-ed services for retardation and learning disabilities declined in 47 states between 1994 and 2003, just as those getting help for autism was rising. In 44 states, the drop exceeded the rise in autism.

I am glad to learn of Professor Grinker’s book. I hope I can read it. And I was glad to see that Tiime, after its unwarrented publication of misinformation about Autism, published Ms. Wallis’ piece.

Link to the Time story by Ms. Wallis. Links to earlier EBD Blog entries on this topic:

• Gillian Baird and colleagues’ report of changes in prevalence in the UK;
• In that same post is moreon Craig Newschaffer and colleagues’ report of higher prevalence of Autism on the younger end of US birth cohort curves.
• Paul Shattuck’s examination of diagnostic substitution in Autism.