Autism was first described by Dr. Leo Kanner (Johns Hopkins) in 1943, with an analysis of 11 children with communication disorders. By 1952, autism was diagnosed by ‘early onset schizophrenia’, only to be renamed ‘infantile autism’ in 1980 and ‘autism disorder’ in 1987. Now, we use ASD (autism spectrum disorder) to cover autistic disorder, Asperger’s syndrome, and other related diseases. As these classifications changed, the number of children diagnosed with the disorder has grown to reach the currently accepted value of 1 in 110 children.
But, just because prevalence is increasing, that does not mean it’s a problem that is caused by parents or vaccines. This statement only creates guilt feelings in the parents of children with ASD, thinking they have failed their children. One must recognize that the prevalence for asthma, diabetes (type 1), and food allergies has also been increasing during this same period. All of these maladies have both genetic and environmentally factors- the issue is to determine all of those factors. As this figure (below) from Nature depicts, we have no clue as to the origins of ASD is almost ½ the cases that exist.
Another popular belief is that folks in science and engineering may display some characteristics of autism- and when they marry and have kids, these progeny have a higher chance to express autism related disorders. This hypothesis was first championed by Dr. Simon Baron-Cohen (Cambridge, UK). His research built on the fact that parents of autistic children have an aptitude for predictable, rule-based system analysis- computer programs, mathematics, machines. Over the past 15 years or so, his research has shown that their children have similar aptitudes. Those same genes that afford the parents the ability to solve these tasks may lead to autistic children when combined with a mate’s similar aptitudes. Some people complain about his research, because he only studies those with high-functioning children with autism (which makes it easier to perform tests and complete questionnaires), which excludes the bulk of the ASD population.
The issue is that the diagnosis of ASD is strictly the domain of psychology- and there are some differences among those diagnosticians and their results. The use of genetic testing has not solved the diagnosis problem, as could be inferred from the diagram above. One can search for duplications/deletions of small segments of DNA or a mismatch in a single nucleotide (A[denosine], C[ytosine], T[hymine], or G[uanine]) in a chromosome pair, for example. These are termed “copy-number variants (CNV)” or “single-nucleotide polymorphisms (SNP)”, respectively. The problem is that these genetic “misses” are not definitive, even though six companies sell such diagnostic tests. And, the costs for these tests are about $ 1500 a pop. Known mutations only are linked to 20% of the cases of ASD. We still have to deal with the 46% of unknowns…
In other words, we still have a long way to go before we can fully identify the underlying causes…
There are several reasons why the incidence might be on the rise. We might have made improvements in diagnosis, or we might be “labeling” a lot of kids who are just over-energetic. Unlike a virus, a disorder can be a matter of interpretation to some degree, much like poverty or grumpiness. It may also be that society is simply defying nature. In that pest, people with autistic genes would have been less likely to live long enough to procreate (yes, I have seen this argument with diabeties), but now we defy natural selection and some might suggest that we are significantly weakening our species by being do-gooders.
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David:
You are correct. This is the reason why a diagnostic test is critical. Relying on psychologists/psychiatrists for a specific diagnosis is problematic. (There have been myriads of studies explaining the differences in diagnoses.) There have been some tests for adults (https://www.adjuvancy.com/wordpress/http:/www.adjuvancy.com/wordpress/brain-scan-detects-autism-in-adults-next-step-is-to-determine-utility-in-children/) developed, but nothing confirmed for children yet…
Roy
Wow, that’s a lot of facts you gave us here, Roy! I agree that all these conditions (not illnesses) has increased lately, when I was a kid we have never heard of anyone having Asperger’s syndrome or food allergies for example. I am not sure though weather it was because these did not exist or we just did not have knowledge of their existence.
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I think over the past decades, Anna, we have determined that many of the children that were “left behind” were those that no one quite understood how different things could be. Now, at least we are trying to decipher what can be made to work for more children.
Roy