Is there an "autism epidemic"?

[nicole]

From TIME:

Is the Autism Epidemic a Myth?
By Claudia Wallis

Epidemic is a powerful word. It generates bold headlines, congressional hearings, research dollars and dramatic, high-stakes hunts for culprits. It's a word that has lately been attached to autism. How else to account for the fact that a disorder that before 1990 was reported to affect just 4.7 out of every 10,000 American children now strikes 60 per 10,000, according to many estimates--the equivalent of 1 in 166 kids?

But what if there is no epidemic? What if the apparent explosion in autism numbers is simply the unforeseen result of shifting definitions, policy changes and increased awareness among parents, educators and doctors? That's what George Washington University anthropologist Roy Richard Grinker persuasively argues in a new book sure to generate controversy. In Unstrange Minds: Remapping the World of Autism, Grinker uses the lens of anthropology to show how shifting cultural conditions change the way medical scientists do their work and how we perceive mental health.

In addition to rising awareness of autism, Grinker points to these factors:

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.

As convincing as Grinker's analysis seems, arguments about the apparent epidemic will probably continue. It's simply impossible to accurately reconstruct the past incidence of the disorder, given how radically definitions have changed. Those who believe the increase is real often focus on the mysterious paucity of autistic adults. With their conspicuous symptoms like hand flapping and little or no language, "I think we would be recognizing them in institutions," says Dr. Robert Hendren, executive director of the M.I.N.D. Institute at the University of California, Davis.

Grinker's answer is that autistic adults are out there but wearing other labels. "Where are all the adults with fetal alcohol syndrome?" he asks. No one over 40 has the condition, thought to affect up to 1 in 500 kids today, because it was not recognized until the mid-'70s. "But no one would say alcoholism among pregnant women just started," says Grinker.

Grinker, whose 15-year-old daughter is autistic, concedes that there's something reassuring about the idea of an epidemic: "Thinking about any disorder as an epidemic is easier than thinking about it in terms of multiple causes, shifting definitions and a scientific reality we are only just beginning to understand." Besides, if a disease suddenly spikes, it seems more plausible that the increase could be reversed--if only we could find the mysterious environmental trigger. With autism, though, that hopeful scenario seems just too simple.

[uscientist]

May 22, 2009 11:41:17 GMT -5 nicole said:

From TIME:

Is the Autism Epidemic a Myth?
By Claudia Wallis

Epidemic is a powerful word. It generates bold headlines, congressional hearings, research dollars and dramatic, high-stakes hunts for culprits. It's a word that has lately been attached to autism. How else to account for the fact that a disorder that before 1990 was reported to affect just 4.7 out of every 10,000 American children now strikes 60 per 10,000, according to many estimates--the equivalent of 1 in 166 kids?

But what if there is no epidemic? What if the apparent explosion in autism numbers is simply the unforeseen result of shifting definitions, policy changes and increased awareness among parents, educators and doctors? That's what George Washington University anthropologist Roy Richard Grinker persuasively argues in a new book sure to generate controversy. In Unstrange Minds: Remapping the World of Autism, Grinker uses the lens of anthropology to show how shifting cultural conditions change the way medical scientists do their work and how we perceive mental health.

In addition to rising awareness of autism, Grinker points to these factors:

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.

As convincing as Grinker's analysis seems, arguments about the apparent epidemic will probably continue. It's simply impossible to accurately reconstruct the past incidence of the disorder, given how radically definitions have changed. Those who believe the increase is real often focus on the mysterious paucity of autistic adults. With their conspicuous symptoms like hand flapping and little or no language, "I think we would be recognizing them in institutions," says Dr. Robert Hendren, executive director of the M.I.N.D. Institute at the University of California, Davis.

Grinker's answer is that autistic adults are out there but wearing other labels. "Where are all the adults with fetal alcohol syndrome?" he asks. No one over 40 has the condition, thought to affect up to 1 in 500 kids today, because it was not recognized until the mid-'70s. "But no one would say alcoholism among pregnant women just started," says Grinker.

Grinker, whose 15-year-old daughter is autistic, concedes that there's something reassuring about the idea of an epidemic: "Thinking about any disorder as an epidemic is easier than thinking about it in terms of multiple causes, shifting definitions and a scientific reality we are only just beginning to understand." Besides, if a disease suddenly spikes, it seems more plausible that the increase could be reversed--if only we could find the mysterious environmental trigger. With autism, though, that hopeful scenario seems just too simple.

very good post. brave of Dr Grinker to stand up like this

[kwombles]

Unstrange Minds: Remapping the World of Autism by Grinker is well worth the read.

[nicole]

Study by Paul T. Shattuck, PhD, published in PEDIATRICS, APR 2006

The Contribution of Diagnostic Substitution to the Growing Administrative Prevalence of Autism in US Special Education

OBJECTIVE. Growing administrative prevalence of autism has stirred public controversy and concern. The extent to which increases in the administrative prevalence of autism have been associated with corresponding decreases in the use of other diagnostic categories is unknown. The main objective of this study was to examine the relationship between the rising administrative prevalence of autism in US special education and changes in the use of other classification categories.

METHODS. The main outcome measure was the administrative prevalence of autism among children ages 6 to 11 in US special education. Analysis involved estimating multilevel regression models of time-series data on the prevalence of disabilities among children in US special education from 1984 to 2003.

RESULTS. The average administrative prevalence of autism among children increased from 0.6 to 3.1 per 1000 from 1994 to 2003. By 2003, only 17 states had a special education prevalence of autism that was within the range of recent epidemiological estimates. During the same period, the prevalence of mental retardation and learning disabilities declined by 2.8 and 8.3 per 1000, respectively. Higher autism prevalence was significantly associated with corresponding declines in the prevalence of mental retardation and learning disabilities. The declining prevalence of mental retardation and learning disabilities from 1994 to 2003 represented a significant downward deflection in their preexisting trajectories of prevalence from 1984 to 1993. California was one of a handful of states that did not clearly follow this pattern.

CONCLUSIONS. Prevalence findings from special education data do not support the claim of an autism epidemic because the administrative prevalence figures for most states are well below epidemiological estimates. The growing administrative prevalence of autism from 1994 to 2003 was associated with corresponding declines in the usage of other diagnostic categories.

Continue reading

[nicole]

Orac analyzes Shattuck's study:

Evidence against an "autism epidemic"

One of the key arguments by advocates claiming a link between mercury in childhood vaccines is that there is an "epidemic" of autism. They'll claim that autism was unknown before the 1930's, when thimerosal was first introduced into vaccines. (Never mind that there are plenty of descriptions of autism-like conditions dating from as far back as the 18th century.) They'll then claim that there is an "epidemic" that accelerated in the 1990's, when additional vaccines were added to the recommended childhood schedule, and that it was the additional mercury from those vaccines that was responsible. It has been argued that a lot of that apparent increase was actually due to a widening of the diagnostic criteria for autism in the early 1990's.

Now there's more evidence to support that view. Just published in the April issue of the journal Pediatrics is a study by Paul Shattuck at the University of Wisconsin, entitled, The Contribution of Diagnostic Substitution to the Growing Administrative Prevalence of Autism in US Special Education. (Hat tip to the "source" who informed me of this article.)

In the paper, Shattuck analyzes special education figures that are being used to bolster claims of an autism "epidemic" and finds them wanting. In essence, diagnostic substitution can explain nearly all of the apparent increase of autism as recorded by the number of children receiving special education services. What that means is that children that would have been diagnosed with something else 15-20 years ago are now being diagnosed with autism. Dr. Shattuck starts with an example from a different condition, mental retardation as one of his reasons for suspecting diagnostic substitution as a cause of the perceived "epidemic":

Continue reading.