The number of children in the United States with autism spectrum disorder is higher than previously thought, according to new data released Thursday by the Centers for Disease Control and Prevention (CDC).
The CDC estimates that 1 in 68 children aged 8 years old had autism in 2010. That’s about 30 percent higher than the previous estimate of 1 in 88 children, which was based on 2008 data and reported in 2012.
It’s less, though, than the 1 in 48 children aged 7 to 9 who were identified in Minneapolis as having autism in a report released last fall by researchers at the University of Minnesota. That figure was also based on 2010 data.
CDC officials caution against interpreting the jump in the prevalence figure as meaning that children are more likely to develop autism today than they were, say, a decade ago. A more probable explanation for the increase, they say, is that pediatricians and others are doing a better job at identifying and diagnosing children with this form of developmental disability.
Wide variations
The data for the CDC numbers comes from 11 different communities across the country, none of which was in Minnesota. All 11 sites participate in the Autism and Developmental Disabilities Monitoring Network, which has been providing estimates of the prevalence of autism among 8-year-old children since 2000.
Health officials collect data on 8-year-olds because most children are diagnosed with autism by that age.
Although the overall prevalence in the latest report was 1 in 68, the estimates varied widely among the 11 sites, from 1 in 45 in New Jersey to 1 in 175 in Alabama.
As in earlier CDC reports, autism was about five times more common among boys (1 in 42) than among girls (1 in 189). The disorder was also diagnosed much more frequently among white than among black or Hispanic children.
The racial and ethnic differences are probably related “to how children are identified and diagnosed and served within their communities,” said Coleen Boyle, director of CDC’s National Center on Birth Defects and Development Disabilities, during a telebriefing session with reporters on Thursday.
The CDC study also found that almost half of children identified with autism in 2010 had average or above-average intellectual ability (an IQ about 85). That compared to a third of children diagnosed with the disorder a decade ago.
“It could be that doctors are getting better at identifying these children, there could be a growing number of children with autism and higher intellectual ability, or it may be a combination of better recognition and increased prevalence,” said Boyle.
New tools for parents
According to the CDC, most children with autism are diagnosed after age 4, even though the disorder can be identified as early as age 2.
Last fall’s University of Minnesota report found that the average age of diagnosis for Minneapolis’ children was 5.
“Research tells us that the earlier a child with autism is identified and connected with services, the better,” said Boyle. “Our message to parents is, if you have a concern about how your child plays, learns, speaks, acts, or moves, take action, don’t wait.”
The CDC offers free online checklists and other materials that parents can use to track their child’s developmental milestones. Government health officials also announced a new initiative on Thursday to encourage universal developmental and behavioral screening for children. Called “Birth to 5: Watch Me Thrive!, the program includes a downloadable “screening passport” that parents can use to track their child’s screening history and results.
The CDC report appears in the March 28 issue of Morbidity and Mortality Weekly Report (MMWR).
The problem is
that there is no way of independently validating a diagnosis of autism, so there’s no way to separate an increase in the rate of -diagnosis- from an increase in the incidence of the condition itself.
To make things worse, an increase in the rate of false positives would result in an -apparent- increase in the rate of successful treatment, since we’d begin with more cases that were never autism.
What we need is a LOT more research (at least one F-35’s worth) on the underlying mechanisms of autism. I suspect that we’ve find that, like cancer, autism is a label for a wide range of conditions produced by many difference causes and reversed by many different cures. Some of the genetic and epigenetic research is interesting, but so far doesn’t account for more than a few percent of the total variance, so it’s of little practical use (yet).
Yeah…
I don’t see how any meaningful research can be conducted at this point, you’re almost certainly looking a variety of different issues now being classified as one in the same. You’re going to find associations with all kinds of things, but how do you know which set of characteristics your correlating with much less establishing any kind of causation?
the only thing is…
In the last 20 years the diagnostic criteria for Autism has been expanded dramatically. It’s likely that these people were always there, just not classified as “Autistic” if they were classified at all.
Autism doesn’t appear to be a discreet set characteristics at this point. I think it’s more accurate to say that more kids qualify for the diagnosis now, rather indicating that more kids are actually Autistic.
Just compare the diagnostic criteria in 1980 to the current criteria:
DSM III (1980)
Diagnostic criteria for Infantile Autism
A. Onset before 30 months of age
B. Pervasive lack of responsiveness to other people (autism)
C. Gross deficits in language development
D. If speech is present, peculiar speech patterns such as immediate and delayed echolalia, metaphorical language, pronominal reversal.
E. Bizarre responses to various aspects of the environment, e.g., resistance to change, peculiar interest in or attachments to animate or inanimate objects.
F. Absence of delusions, hallucinations, loosening of associations, and incoherence as in Schizophrenia.
Vs. the current criteria:
DSM-IV (1994) and DSM-IVR (2000)
299.00 Autistic Disorder
A total of six (or more) items from (1), (2), and (3), with at least two from (1), and one each from (2) and (3):
Qualitative impairment in social interaction, as manifested by at least two of the following:
marked impairment in the use of multiple nonverbal behaviors such as eye-to-eye gaze, facial expression, body postures, and gestures to regulate social interaction.
failure to develop peer relationships appropriate to developmental level
a lack of spontaneous seeking to share enjoyment, interests, or achievements with other people (e.g., by a lack of showing, bringing, or pointing out objects of interest)
lack of social or emotional reciprocity
Qualitative impairments in communication as manifested by at least one of the following:
delay in, or total lack of, the development of spoken language (not accompanied by an attempt to compensate through alternative modes of communication such as gesture or mime)
in individuals with adequate speech, marked impairment in the ability to initiate or sustain a conversation with others
stereotyped and repetitive use of language or idiosyncratic language
lack of varied spontaneous make-believe play or social imitative play appropriate to developmental level
Restricted, repetitive, and stereotyped patterns of behavior, interests, and activities, as manifested by at least of one of the following:
encompassing preoccupation with one or more stereotyped and restricted patterns of interest that is abnormal either in intensity or focus
apparently inflexible adherence to specific, nonfunctional routines or rituals
stereotyped and repetitive motor mannerisms (e.g. hand or finger flapping or twisting, or complex whole body movements)
persistent preoccupation with parts of objects
Delays or abnormal functioning in at least one of the following areas, with onset prior to age 3 years: (1) social interaction, (2) language as used in social communication, or (3) symbolic or imaginative play.
The disturbance is not better accounted for by Rett’s disorder or childhood disintegrative disorder.
DSM V
is in the works.
Probably be even more of a ‘Chinese restaurant menu’ (pick two from column A and one from column B).
The problem with the DSM has always been that it’s a description of behaviors (symptoms if you wish) which are effects, each of which can have many different causes. All it tells you is when to use a label; not what the underlying mechanism is. It really says nothing about the causes of the behaviors that it labels.