Study : Global Prevalence of Autism and Other Pervasive Developmental Disorders.
Posted May 17 2012 7:48am
I am constantly amazed that otherwise rational people can look at the steady upward march of autism prevalence numbers and confidently state that it isn't real. Certain researchers seem to always pull out the better awareness, broadening criteria, diagnostic substitution, and availability of services arguments to explain away any increases without ever taking the time to empirically demonstrate that these factors are actually responsible for the increase.
It might be just me, but if you are going to put forth a theory then you had best have evidence to support that that theory. Otherwise your theories are just speculation and are no better than all of the other unsupported ideas surrounding autism, such as the extreme male brain theory of autism.
I haven't read the full text of this recent paper on global prevalence (abstract below), but from the abstract it seems to yet another "the sky isn't falling, we are just better at seeing it" type of paper. Which, in light of all the recent research into autism prevalence and causes, just seems badly out of touch.
I have to wonder at what point the epidemic denialists will stop pulling out the same tired reasons to keep explain away the ever increasing number of people with autism. As worldwide autism rates go from well under 1% to Korea style over 2% and beyond, at exactly what point will the denialists stop using the exact same theories to explain each and every increase? How many times can the spectrum double before these reasons start to sound just like excuses?
Are we really going to have to wait for the sky to finish falling and literally hit them in the face before they will admit that there is in fact a problem?
Global Prevalence of Autism and Other Pervasive Developmental Disorders.
Elsabbagh M, Divan G, Koh YJ, Kim YS, Kauchali S, Marcín C, Montiel-Nava C, Patel V, Paula CS, Wang C, Yasamy MT, Fombonne E.
Abstract We provide a systematic review of epidemiological surveys of autistic disorder and pervasive developmental disorders (PDDs) worldwide. A secondary aim was to consider the possible impact of geographic, cultural/ethnic, and socioeconomic factors on prevalence estimates and on clinical presentation of PDD. Based on the evidence reviewed, the median of prevalence estimates of autism spectrum disorders was 62/10,000. While existing estimates are variable, the evidence reviewed does not support differences in PDD prevalence by geographic region nor of a strong impact of ethnic/cultural or socioeconomic factors. However, power to detect such effects is seriously limited in existing data sets, particularly in low-income countries. While it is clear that prevalence estimates have increased over time and these vary in different neighboring and distant regions, these findings most likely represent broadening of the diagnostic concets, diagnostic switching from other developmental disabilities to PDD, service availability, and awareness of autistic spectrum disorders in both the lay and professional public. The lack of evidence from the majority of the world's population suggests a critical need for further research and capacity building in low- and middle-income countries. Autism Res 2012