Earlier today, California Watch, a project of the Center for Investigative Reporting, posted a short piece on rising rates of autism and declining rates of students with “learning disabilities”:
More than 680,000 students – 11 percent of all California public school students – are enrolled in special education. The number of students diagnosed with autism climbed from 17,508 in 2002 to 59,690 in 2010, the Lucile Packard Foundation for Children’s Health found.
Students with autism represented 8.8 percent of all special education enrollment last year, up from 2.6 percent in 2002. Other health impairments – defined by the state as “limited strength, vitality or alertness, due to chronic or acute health problems,” such as a heart condition, asthma, epilepsy or leukemia – are also on the rise, comprising 7.9 percent of disabilities among special education students.
At the same time, the number of special education students with a learning disability – the most common diagnosis – is falling. In 2002, 52.4 percent of students had a learning disability, compared to 42.3 percent in 2010. Speech or language impairment affects about one-quarter of special education students.
At first blush, this data would seem to lend credence the idea that the well-documented (and much discussed) rise in autism diagnoses does not actually correlate to an actual increase in autism in the population.* Except…well, except for the fact that correlation does not equal causation. Maybe budget cuts in special ed programs are squeezing out students with other diagnoses — while autism, which has received an enormous amount of attention in the media over the past decade, has received a larger share of educators’ attention. Maybe more students who are diagnosed with other learning disabilities are going to private schools. Maybe this is attributable to something no one has even thought of yet.
The point is, we just don’t know. As the California Watch piece itself notes, “The data do not explain these shifts in disability diagnoses.”
* Roy Richard Grinker, the author of Unstrange Minds, has written about the effects of changing diagnostic criteria on autism rates extensively; he documents the way the DSM has evolved in this regard here.