Autism: Sharp spike in cases a result of shifting diagnosis methods, researchers say

[progressoid]

The way autism is diagnosed has led to an apparent tripling in cases in recent years that does not reflect reality, researchers say.

Rather, more youths with intellectual or developmental disabilities are being reclassified as autistic, the United States-based study published in American Journal of Medical Genetics found.

...

The prevalence of autism in the US was just one in 5,000 in 1975.

It leapt to one in 150 in 2002, and reached one in 68 in 2012, according to the US Centres for Disease Control and Prevention.

"This new research provides the first direct evidence that much of the increase may be attributable merely to a reclassification of individuals with related neurological disorders rather than to an actual increase in the rate of new cases of autism," the study authors wrote.

Penn State University scientists found "no overall increase in the number of students enrolled in special education".

"They also found that the increase in students diagnosed with autism was offset by a nearly equal decrease in students diagnosed with other intellectual disabilities that often co-occur with autism."

Therefore, what may appear to be an epidemic of autism is more likely the result of shifting patterns of diagnosis over time.

... http://mobile.abc.net.au/news/2015-07-23/autism-diagnosis-leads-to-increase-in-cases/6642006

[Igel]

1. If true, this is fairly convincing.

"They also found that the increase in students diagnosed with autism was offset by a nearly equal decrease in students diagnosed with other intellectual disabilities that often co-occur with autism."

[Fortinbras Armstrong]

2. I was only diagnosed with Aspergers in 1990, when I was 42.

When he was ten, my youngest son had tremendous difficulty socializing in school, so my wife and I took him to a psychiatrist. The shrink said that our son had Aspergers, and described the classic symptoms. My wife and I looked at each other, and said, almost in chorus, that he was describing me.

I had once been diagnosed with a personality disorder, I forget which one.

[Bearware]

3. Of course it must be changes in diagnostic criteria, how could it be anything else...

Gosh that must mean the great increase in cases of type 1 diabetes is probably also due to the way type 1 diabetes is diagnosed - right?

The rate of type 1 diabetes is increasing at 3%/year. In Finland, the incidence is a high of 57 per 100,000 but the U.S. is only 8 to 17 per 100,000 per year. The Finns must be changing the criteria 3 times a year. (https://en.wikipedia.org/wiki/Diabetes_mellitus_type_1#Epidemiology ... 3%/year)

The following has a more interesting explanation for the Finnish situation:
http://www.ucsd.tv/search-details.aspx?showID=15771