Professor Tony Charman's quarterly research brief: prevalence of autism

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Is autism on the rise? Professor Tony Charman has written a report summarising the research exploring the prevalence of autism over the years, which you can read in the evidence base section here.

What do you think? How can we get accurate figures for the prevalence of autism? Are there the resources to meet the needs of increasing numbers of people diagnosed as being on the autism spectrum? We'd love to hear your thoughts...

Edited on February 23, 2017 - 9:20am


October 21, 2018 - 12:58am

Autism is absolutely a disorder, the way people take offence at the wording derails from the truth of the matter and the real issues that should be addressed about autistic peoples' needs. High-functioning autistics don't represent all autistics by any degree.  Agree with quite a bit of what zemanski says.  There has been a huge rise in autism and no, it's not down to improved diagnosis.

Autism Research & Media

Dr Tony Attwood on females with autism

At 22:45 in this Channel 4 "Born Naughty" Episode 2 video, Tony talks about autism in girls and he now says that the autism gender ratio is "probably 50:50"  I have said for some time that the gender ratio is equal, so it's nice to finally have a respected and renowned professional in the field acknowledge the reality too.

Another expert who agrees with this is Dr Judy Eaton of Help4Psychology.

Interim survey results: "Autism Parents Survey on Health & Education Experiences".  The survey can be taken here.

Interim survey results: "Autism Parents Survey on Social Care Experiences", the survey can be taken here.  Both surveys are ongoing and are only 10 questions each.  Please share far and wide.

Video of an autistic girl called Carly Fleischmann, considered very low functioning, who because of their assumptions, amazed everyone with her intelligent level of communication by PC.​  Not so "low functioning" after all...

New research on autistic women as mothers - we are great mothers!


Extract from a very important discussion about the accepted (but non-diagnostic) terminology of "low functioning" and "high functioning" in autism:​


"The confusion among parents and professionals is between "level of functioning" (intellectual ability), and "severity of autism." I know of children who are labeled "high functioning" who have severe autistic traits (very rigid/inflexible thinking, very resistant to change and uncertainty, and meltdown over simple snags in their day.) However, they are considered "high functioning" because they are very verbal, get good grades in school, and can do personal care independently. I have also met children who are considered "low functioning" because they are nonverbal, have difficulty with performing personal care, and difficulty with academics, but who's autism traits are less severe; more flexible in their thinking, handle daily transitions easier, can reference others better, and have fewer meltdowns. So, level of functioning doesn't also correlate with the severity of the autism. Just because a child is labeled “high functioning”, doesn’t mean he doesn’t have severe autism. Many people confuse the two, which can often exclude some from treatment, or lower the expectations for others."


False accusations against parents of autistic children - the myth of FII/MSBP (as reported by Autism Eye magazine) and how asking for support for your child can get you accused.   The NAS is aware of these accusations but has yet to speak out.  People are questioning what help the NAS is to people.


These research findings of 1 in 64 are not the 1% epidemiology that official figures claim (but it is 1.5625% ). And when you see the 2nd paragraph about all the undiagnosed children out there too (which makes it , it's clear authority is lying or not bothering to keep accurate statistics as all authorities are now required to do! There is an increase of autism - the so-called autism epidemic. Clearly there is an environmental trigger in the genetically vulnerable for at last a large sub-section of autism, causing these rising rates.


"Prevalence of autism-spectrum conditions: UK school-based population study" 2009 study by Simon Baron-Cohen et al.

"By adjusting the estimate derived from the SEN register (that is, based on whole classes and not a 29% response) for the additional number of cases that would be expected if all the children were directly observed, the prevalence estimate is 157 per 10 000 or 1 in 64 (95% CI 99–246).

Overall, for boys and girls together, for every three known cases, there are at least two undiagnosed cases of autism-spectrum conditions (making the prevalence well over 2%) in the primary school population, or a ratio of 3:2 (known:unknown). There is no evidence of a difference in the undetected estimate of cases for boys and girls, despite a clear difference in the overall ratio of boys:girls with autism-spectrum conditions."


October 21, 2018 - 1:07am

(Please ignore the text between first para and the Baron-Cohen study in the previous post, accidental copy and paste and irrelevant to this thread).

A Prospective Longitudinal Assessment of Medical Records for Diagnostic Substitution among Subjects Diagnosed with a Pervasive Developmental Disorder in the United States

"The results of the present study revealed that subjects diagnosed by healthcare providers with a PDD in comparison to those diagnosed with MR or CP, within the VSD database were significantly different populations, and, as a result, these differences suggest that diagnostic substitution cannot fully explain the increase in diagnosed PDD during the 1990s within the US. The observations made in the present study call into question the sufficiency of previous studies, which have sought to evaluate diagnostic substitution as an explanation for the increase in PDD during the 1990s in the US by comparing only prevalence changes in diagnosed PDD to prevalence changes in diagnosed MR or CP; such an evaluation would seem too superficial to yield any valid results without additional clinical comparisons of the populations in question. The observations made in the present study also provide critical insights for healthcare providers attempting to identify important and distinguishing clinical features associated with a diagnosis of PDD in comparison to a diagnosis of MR or CP. Among the important clinical features associated with those diagnosed with a PDD observed in the present study were: elevated male/female ratio (males significantly more likely than female to be effected); delayed mean age of initial diagnosis (mean age of initial diagnosis between 2 and 4 years-old); and the lack of significant problems at birth in comparison to those with a MR or CP diagnosis. By contrast, among the important clinical features observed in the present study and associated with those diagnosed with MR or CP were: roughly equal male/female ratio (males roughly equally likely with female to be effected); early mean age of initial diagnosis (mean age of initial diagnosis within the first 2 years of life); and with significant problems at birth in comparison to those with a PDD diagnosis."