Response to David Oliver I (The Indisputable Rise in Autism)
I fear David Oliver's most telling remark (as a senior geriatrician) is "I have no content expertise in ASD of any kind" . The evidence is that he is operating with a population where ASD is still very rare, otherwise he would meet cases commonly and often they would be among his most intractable - he would also have to train to deal with them. This is perhaps in line with Järbrink and Knapp's calculation of the cost autism back in 2001 based on an overall prevalence rate of 5 in 10,000 .
To revisit the evidence I presented in my first letter  on this thread, I have long been sceptical of National Autistic Society's projection of a prevalence rate in the region of 1 in 100, without ever having located the cases i.e. it remains a projection. Presently they project 700,000 cases  across the UK which is still more than one million short of the rates we are now talking about in children. A National Statistics survey of 2009 claimed to detect an adult rate of 1 in 100 had to be downgraded in 2016 to "experimental statistics" and the same problem arose with their 2016 paper [5, 6]. As of 2013 the Department of Works and Pensions knew of only 128,950 cases of ASD (in the region of 1 in 500) and it is likely these were preponderantly children [7,8].
While I have no doubt that new cases are sometimes detected and diagnosed among adults there seems no persuasive evidence that numbers of this order exist (particularly among the older adults). Nor has there ever been to my knowledge a massive re-allocation of diagnoses among adults substantiating any substitution hypothesis. When Eric Fombonne talked along these lines in 1999 he was still only talking about a prevalence of 1 in 500 . On the other hand, the figures I am talking about here are replicated in a recent time trend analysis of California data (the most comprehensive for the United States) reaching back to 1931 .
With all the alleged improvements in recognition what we are recognising is manifestly more and more children.
It remains disturbing that these catastrophic public issues are left to be raised by a private citizen.
I also recommend the excellent book ‘Denial’ by my Age of Autism colleagues Mark Blaxill and the late Dan Olmsted .
 David Oliver, 'Re: Measles: Europe sees record number of cases and 37 deaths so far this year' 24 August 2018, https://www.bmj.com/content/362/bmj.k3596/rr-7
 Järbrink K, Knapp M, 'The economic impact of autism in Britain', Autism. 2001 Mar;5(1):7-22.
 John Stone, ‘What about autism?’ 21 August 2018, https://www.bmj.com/content/362/bmj.k3596/rr-0
 National Autistic Society 'Autism Facts and History' https://www.autism.org.uk/about/what-is/myths-facts-stats.aspx
 Brugha et al, 'Adult psychiatric morbidity survey 2014: Chapter 6 Autistic Spectrum Disorders' https://files.digital.nhs.uk/pdf/1/o/adult_psychiatric_study_ch6_web.pdf
 Freedom of Information request 2014-722, https://assets.publishing.service.gov.uk/government/uploads/system/uploa...
 John Stone, ‘Re: The rise in autism - this is how the Department of Health replied in 2000. What about now?’, 8 August 2018, https://www.bmj.com/content/361/bmj.k1674/rr-12
 Eric Fombonne, 'The epidemiology of autism: a review', Psychol Med. 1999 Jul;29(4):769-86, https://www.ncbi.nlm.nih.gov/pubmed/10473304
 Cynthia Nevison, Mark Blaxill, Walter Zahorodny, 'California Autism Prevalence Trends from 1931 to 2014 and Comparison to National ASD Data from IDEA and ADDM', Journal of Autism and Development Disorders, 5 July 2018 https://link.springer.com/article/10.1007%2Fs10803-018-3670-2
 Mark Blaxill and Dan Olmsted, ‘Denial: How refusing to face the facts about our autism epidemic hurts children, families and our future’, Skyhorse 2017.
Competing interests: No competing interests