Autism research in 2023: a bit of a game-changing year

 So, autism research in 2023. It’s been quite a year. Let me (briefly) tell you why.

The autism numbers game: the only way is (still) up. Northern Ireland, where some great work is done to plot the annual (estimated) prevalence rate of autism spectrum disorder (ASD) in school-aged children, said 1 in 20 (or 5%) in 2023. The US CDC said an estimated 1 in 36 8-year olds (2.7%) were autistic in 2020. The CDC also said 1 in 47 4-year olds were autistic (2%). Scotland also recently produced data observing “The prevalence of autism was 2.60% (10,089 children) in 2022. This represents a 31.98% increase from the 2018 prevalence of 1.97% (7883 children).” That Scottish data, by the way, only covered those at primary school (aged 4ish-12ish years). Other sources too are still showing a growth in the prevalence of autism across other parts of the globe, including a near 5% rate of behaviours consistent with autism or ASD in the Hadza of Tanzania. All data on autism prevalence is still only heading in one direction: UP. 

Importantly, the old ‘all better awareness’ arguments are slowly fizzling out as the effects of those prevalence stats are starting to show on resources and infrastructure that seemingly haven’t kept pace with the growth in numbers. Indeed, one of the head people related to the CDC autism figures, went as far as to say that the stats don’t really support ‘better awareness’ as the primary driver given that the increase is showing across various different ‘levels’ of autism that are/were unlikely to be missed or thought to be something else. Certainly here in the UK, I don’t think I’ve ever read so many reports about school place shortages (particularly specialised school place shortages) as I have this year. And unfortunately, with an estimated 140,000 people (mostly children and young people) awaiting assessment in England alone, I fear the squeeze on resources is just going to get worse and worse. Anyone care to start asking ‘why the increase’ yet?

CDC says yes to ‘profound autism’. Speaking of autism ‘levels’ (as in DSM-5 autism levels of support or the ICD-11 condition combinations), the CDC did something else rather important this year: producing the first ever report on the rate of profound autism in the US. So, for data covering the years 2000-2016, and using the descriptor “classified as having profound autism if they were nonverbal, were minimally verbal, or had an intelligence quotient <50” they determined that 26.7% of those with autism fitted into the profound autism category. An estimated quarter of autistic people are profoundly autistic. That’s quite important.

There were mixed reactions to the CDC use of the term profound autism. Many people were happy to see it, given that it now lays the foundations for more research and more understanding that despite being united by a triad/dyad of symptom combinations, not everyone experiences autism in the same way. Look no further than the awful early mortality statistics following the deadly triad that is autism, wandering/elopement and water safety to see this in action. Of course autism by virtue of just being diagnosed, means support is required for everyone with the diagnosis. But that support will arguably differ depending on whether you possess things like communicative speech and language, present with things like self-injurious or aggressive behaviours and/or need 24-7 care to ensure that your daily needs are fulfilled. Indeed, I often think that the general lack of support post autism diagnosis is a big driver in the reticence to adopt the term profound autism in some quarters. But should people be so reticent? I mean we have similar distinctions when it comes to experiences of learning (intellectual) disability and nobody seemingly bats an eyelid there. 

There is however more to do on profound autism. This ties into other changes that are needed when it comes to assessing things like cognitive functions and communication (verbal or non-verbal) ability in relation to autism. That’ll follow as the term beds in and builds up more of a research base. Asperger syndrome gone, profound autism steps in.

What else? 

Non-persistence of autism in (some) young kids. 2023 also gave a lot more credence to the idea that the saying ‘all autism is lifelong’ probably isn’t as accurate as you might think. Looking at the developmental trajectories of around 200 kids, all diagnosed early with autism, saw about a third of them not continuing to meet the diagnostic threshold for autism/ASD at ages 5-7 years according to a big study. Other independent work also illuminated this topic and argued against the ‘just misdiagnosed’ suggestions that some people might make and that also the state of ‘autism free’ might have important implications for various other issues too.

This was a particularly important finding for me given our paper from a few years back talking about inborn and lifelong not necessarily being the most accurate phrases for all autism. It also accords with various other studies in related areas observing that diagnoses like ADHD and depression for example, aren’t lifelong labels for absolutely everyone either. Although I noted some people tried to talk about ‘masking’ and ‘camouflaging’ as being the reasons why young kids in that JAMA study didn’t meet the thresholds for autism having previously done so, I do have to ask whether they’ve ever seen autistic kids at this age. Indeed, any child at this age, who generally aren’t renowned for their developed social etiquette abilities covering masking et al (this is also the reason that the gold-standard autism assessment instrument, the ADI-R, codes 4-5 years separately from ‘current behaviour’). As to why autism doesn’t persist for some, well, we don’t know exactly. There was talk of intervention potentially playing a role (behavioural intervention) but it’s probably going to be a bit more complicated than just that. For now, we await further studies on this important topic including more longitudinal ones and perhaps also looking at the biology behind this phenomenon. If I was to speculate about why there is autism non-persistence for some, I might be inclined to say ‘look to infection’ for some, and how, more and more, we’re learning that infection and immune responses to infection can manifest as behaviour and developmental issues as well as in immune biology. Just me speculating, so pay no mind (although that autism in Hadza children study did nicely reignite my interest in how infections like malaria can, through various mechanisms, also seemingly lead to autism).

The gut-brain axis is important to autism. I know a lot of people already appreciate this, but seeing it in a peer-reviewed mega paper in 2023 adds a lot more weight to it. Said paper trawled through huge amounts of data about gut bacteria and the like, and concluded that there is something to see both as observation and also as potential intervention. Authors even mentioned the words ‘faecal matter transplant’ (FMT) in the context that what goes on in the gut doesn’t necessarily stay in the gut, and something that is rising in some autism research and other circles. Allied to the gut-brain axis stuff was the reporting from other mega review papers observing that gastrointestinal (GI) symptoms are present in roughly 55% of children with autism, compared with about a quarter of non-autistic children. Constipation comes out on top. So fixed to clinical advice about treating such issues published over 10 years ago, maybe now is the time to preferentially screen and treat such issues in the context of autism? Perhaps recognise that the gut and brain are connected for quite a few labels/conditions? More on that shortly.

Various medical issues are over-represented in autism. More important data points to the various clusters of medical (somatic) issues that seem to accompany autism across the age ranges. Ranging from cardiovascular conditions to immune-mediated conditions, various studies confirmed what quite a few people already knew. With my gluten research hat on (I don’t actually have a hat made of gluten), I was glad to see that the archetypal gluten-related autoimmune condition called coeliac disease was given mention. Who knows, between coeliac disease and the slightly greyish area of non-coeliac gluten issues that seem to be over-represented alongside autism, there’s further hope for wider screening and use of a gluten-free diet in the context of autism? Oh, and just before you inquire about the research base in this area, here’s a couple of meta-analyses from the last few years - see here and see here - saying it might be worth a shot (minus any clinical or medical advice given or intended).

And there was yet more research on the psychiatric and behavioural issues that seem to be over-represented alongside autism. Importantly, and I do think needs a lot more investigation, one study out of Canada stressed the need to look at comorbid psychiatric issues as being an important driver of suicidal behaviours in the context of autism. I know such behaviours are complex and often very individual with a heavy biopsychosocial tilt, but there’s a wealth of evidence out there already suggesting that depression, bipolar disorder, personality disorder and schizophrenia spectrum disorders all convey a heightened risk for suicidal behaviours. All those conditions are well over-represented alongside a diagnosis of autism (yep, an estimated 1 in 10 autistic people will potentially ‘transition’ to schizophrenia). Screen, screen and treat (including, where appropriate, more clinical emphasis on the archetypal anti-suicidal agent that is lithium used in the right context).

Late 2023 research entry: CM-AT results are really, really, really promising. I’ve been following the CM-AT story for quite a while on this blog and beyond. Basically, it concerns a pancreatic enzyme therapy designed for autism that has already crossed quite a few methodological trial hurdles. Then, in November 2023 lo and behold, the results of a double-blind, placebo-controlled trial that say, yes, following the gold-standard trial design, CM-AT is good for treating/managing irritability and agitation in the context of autism in pre-schoolers. Said treatment is also likely safe and effective. This is a potential game-changer and opens the door to things like regulatory approval. Also, exquisite evidence for the whole ‘behaviour is biology’ tenet and the important role of the gut-brain axis in autism, yet again.

There was so much more other science published this year, across all-manner of different topics. Certainly far too much for me to put into one blogpost. I’m a great believer in your citizen scientists and so would encourage everyone to look-see and take part. I can’t help but draw your attention to another paper that basically said the ‘person with autism’ vs ‘autistic person’ arguments typically seen on social media aren’t really worth a dime. Ask the person how they want to be addressed. Oh, and remember, people aren’t ‘neurotypes’ either. They’re people. 

And finally… Saying farewell to Donald.

Finally, [I can see you’re yawning] a non-sciency thing to mention. ‘Patient 1’ from the great Leo Kanner’s seminal paper describing autism - Donald Triplett - passed away. If you’ve ever read or watched ‘In a Different Key’ you’ll have read about him or seen him. Of all the things said about Donald in the various obituaries to him, I think the overwhelming idea that comes across is how much community was important to him; both being part of a supportive community and having a great community around him. Loads of lessons to be learned there. My advice: seek out those who wish to foster community, and there are lots of good people of this ilk. Here's to 2024 and beyond.

Iceberg! Have we reached a tipping point in autism numbers and assessment referrals?

Sorry. I really am. I'm back at the autism research blogging yet again, twice in a week. I know some people will be unhappy about that (I can hear the Twitterer cries already: 'keep yer bloody mouth shut!') but hopefully some won't be so unhappy. But writing this on a nice sunny March Sunday evening with a rerun of Titanic playing on the telly, I'm gonna talk about whether or not we've just hit the iceberg when it comes to US autism (estimated) prevalence (and those from elsewhere) and the huge backlog of autism referrals that's been making news here in Blighty aka dear old England. I'll also come clean and mention that I actually do like the film Titanic. There I said it. 

I appreciate that my use of the word 'iceberg' in the context of this blog is not likely to sit well with some people. How dare I talk about icebergs in the context of autism prevalence and such like? Well, I dare because right now there's a lot of people who are genuinely concerned that more than ever we might have started to head into and indeed, already started to scrape past, an iceberg that's been on the horizon for a number of years. And in the current climate of post-pandemic financial and resource pressures, we haven't exactly got the strongest of hulls in this societal ship in which we're all passengers on. 

So, last week we had the estimated autism prevalence figures for 8-year olds in the United States from the CDC (see here). Actually we had another set of (estimated) figures relating to 4-year olds too (see here). The headline figure: well, words like 'all-time high' have been used to cover the 1 in 36 8-year olds estimated to have autism or an autism spectrum disorder (ASD). As for 4-year olds, and as per other reports (see here), 1 in 47 4-year olds was the headline figure, a leap from previous reports for this age group (1 in 59 in 2018). Both sets of figures chart the estimated numbers of cases of childhood autism and illustrate the ever upward trend that we've been seeing over the past few decades in the US and beyond.

Most press coverage of the CDC data have not sugar-coated it. Yes, there's been talk about how racial disparities in screening and assessment have been reduced in the recent figures and that's a good thing. There's also talk about the (subtly) declining male:female ratio which again, represents good progress in detection and identification. But then the conversations move to the need to provide suitable services. Y'know things like education, social and health services, and this is where the tone gets a little more serious as per the realisation that there's probably not enough suitable or appropriate services for everyone, and what services there currently are, are probably going to become even more scarce as more people need them. As an aside it's interesting too that this time around, some discussions on the new CDC figures have basically poo-pooed the whole 'it's all better awareness' arguments: "This is not just a phenomenon of becoming more sensitive to subtly impaired kids" according to one very senior person intricately involved in the CDC process of autism counting. Progress indeed given the amount of times that argument has been used, fairly unscientifically, in the past.

On this side of the Pond, I think we're starting to really see that process of 'lack of suitable services' playing out in real time. We - the UK we - are still waiting for a truly national autism prevalence initiative but we have some good counting processes in place in relation to countries of the UK like Northern Ireland and their forward-thinking in collecting and publishing school-aged autism prevalence data (see here). Northern Ireland is, I think, due to report in a few weeks time but the last time around the prevalence of autism in school-aged children came it at 1 in 21 children (see here) or 4.7% of school-aged children with autism in 2021/2022. I also happened to stumble on some other, more England-based data recently (see here) that mentioned that "2.84% of 10-14-year olds were diagnosed (1 in 35)." Obviously, one has to be a little careful with that last statistic. What this means is that the latest CDC figures for the US are not an isolated incident. They're more likely part of a global trend where the old 1% prevalence figure is completely out of sight in the rear view mirror.

As to that 'lack of suitable services'? Loads of examples to pick from. Take for example the recent BBC news report (see here) on twins, yes twins, both diagnosed with autism (and dare I say autism heading more towards 'profound'), both with EHCPs (education and healthcare plans) yet one twin offered a place at a specialised setting, the other not. The reason: the specialised setting is 'over-subscribed'. Twins. There's loads more other examples like this. Such examples complemented (if that's the right word) by multiple reports of plans to build more and more specialised schools with seemingly little realisation that said schools take a while to be built and then also need to be suitably staffed, which leads us down another potential rabbit hole. Another aside: we have some of the best teaching cupboards (yes, you heard right) in the world here in England (see here).

And if you think things are critical when it comes to resources for those lucky enough to already have a diagnosis, spare a thought for the thousands and thousands of people - predominantly school-aged children - who are waiting just to get on a waiting list for autism assessment (see here). In England alone there's about 140,000 people waiting at the time of writing (see here), again predominantly school-aged children. And now another reality: one particular part of England has recently decided that the huge numbers of people, again predominately children, wanting an autism assessment will be 'triaged' to filter out 'the most needy' (see here). That's triage as in what's normally seen on the battlefield when care is rationed according to those most in need. So children now have to be 'in crisis' before they're put on a list for a referral for autism assessment. We've hit the iceberg, haven't we? 

I don't really know what else to say about all this. Yes, it's great that everyone is getting better at recognising autism. Yes, it's great that more people are being detected and referred for an assessment. We can pat ourselves on the back for that. Unfortunately, as a society we've had our collective heads buried in the sand about what rising numbers of need actually means. And now, it's having real-world implications for many people and their loved ones. 

How many lifeboats did you say we have?

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Maenner MJ, Warren Z, Williams AR, Amoakohene E, Bakian AV, Bilder DA, Durkin MS, Fitzgerald RT, Furnier SM, Hughes MM, Ladd-Acosta CM, McArthur D, Pas ET, Salinas A, Vehorn A, Williams S, Esler A, Grzybowski A, Hall-Lande J, Nguyen RHN, Pierce K, Zahorodny W, Hudson A, Hallas L, Mancilla KC, Patrick M, Shenouda J, Sidwell K, DiRienzo M, Gutierrez J, Spivey MH, Lopez M, Pettygrove S, Schwenk YD, Washington A, Shaw KA. Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years - Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2020. MMWR Surveill Summ. 2023 Mar 24;72(2):1-14. doi: 10.15585/mmwr.ss7202a1. PMID: 36952288.

Shaw KA, Bilder DA, McArthur D, Williams AR, Amoakohene E, Bakian AV, Durkin MS, Fitzgerald RT, Furnier SM, Hughes MM, Pas ET, Salinas A, Warren Z, Williams S, Esler A, Grzybowski A, Ladd-Acosta CM, Patrick M, Zahorodny W, Green KK, Hall-Lande J, Lopez M, Mancilla KC, Nguyen RHN, Pierce K, Schwenk YD, Shenouda J, Sidwell K, Vehorn A, DiRienzo M, Gutierrez J, Hallas L, Hudson A, Spivey MH, Pettygrove S, Washington A, Maenner MJ. Early Identification of Autism Spectrum Disorder Among Children Aged 4 Years - Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2020. MMWR Surveill Summ. 2023 Mar 24;72(1):1-15. doi: 10.15585/mmwr.ss7201a1. PMID: 36952289.

Autism diagnosis, numbers and politics

It's been a while since I lasted posted on this blog. Apologies to those who've enjoyed my musings but time has been in short supply these past few weeks. But I'm here now...

Today I want to bring to your attention a couple of papers and news items that have caught my eye in the past few weeks. The first is the paper by Eya-Mist Rødgaard and colleagues [1] which garnered quite a bit of media attention (see here). The crux of the Rødgaard findings were that "differences between individuals with autism and those without autism have decreased over time, which may be associated with changes in diagnostic practices." It was a meta-analysis paper and so kinda reiterated what had already been discussed in the peer-reviewed science literature before, in that the autism of today might not necessarily the same as the autism of yesteryear (see here).

Second up is another recent paper from Benjamin Zablotsky and colleagues [2] (a name mentioned a few times on this blog) indicating that the only way is up when it comes to diagnoses of developmental disabilities such as autism. I noted that some interpretations of the Zablotsky results headed down the old 'better awareness' and 'not a true rise' routes (see here) despite the quite astounding increase in cases from "1 in 91 children in 2009 to 1 in 40 in 2017." In any other label / condition / disorder, such a rise would probably provoke some important questioning about why the increase and what factors could be associated with it (including the Rødgaard explanation). Needless to say that children become adults, and quite a lot of those 1 in 40 children are going to require more Government planning and money to ensure that they live good, healthy and productive lives as both children and adults. And just in case you think such a rise is a United States issue only, take a look at the stats for Northern Ireland in recent years (see here and see here) and tell me that there isn't a true rise there either.

Finally a few interesting lay articles have been published in recent weeks which deserve highlighting and debating. The first from neuroscientist and science writer Mo Costandi ruffled some feathers in his critique of the concept of neurodiversity. The by-line to the article said it all: "The movement has good intentions, but it favours the high-functioning and overlooks those who struggle with severe autism." The second article from Steve Silberman tackles a slightly different, but nonetheless related issue, on how "Greta Thunberg became a climate activist not in spite of her autism, but because of it." Both articles, whilst sharing some differences, stress how the label of autism covers a wide, wide variety of presentations and outcome. They also serve to highlight how there is seemingly no way that one can possibly advocate for the entire autism spectrum as some sort of singular label / condition / disability based on the different wants, needs and desires of such a diverse population. The sooner we start to take the plural 'autisms' more seriously, the better for everyone...

To close, no two brains are the same as seen in this 'cool' graphic. In the coming weeks, I'll be talking about a few papers that should be appearing in the peer-reviewed domain that I've been involved in authoring that stress such an important point.

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[1] Rødgaard EM. et al. Temporal Changes in Effect Sizes of Studies Comparing Individuals With and Without Autism: A Meta-analysis [published online ahead of print, 2019 Aug 21]. JAMA Psychiatry. 2019;e191956.

[2] Zablotsky B. et al. Prevalence and Trends of Developmental Disabilities among Children in the United States: 2009–2017. Pediatrics. 2019. September.

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Edentulousness (no natural teeth) and intellectual (learning) disability

Edentulousness: "The property of being edentulous; lack of teeth."

I was brought to talk about edentulousness on this blog as a result of the findings reported by Kinnear and colleagues [1] and their observations suggesting that: "Adults with IDs [intellectual disability] have a high prevalence of edentulousness."

Based on data from an "adult cohort with IDs residing in Greater Glasgow and Clyde, Scotland", researchers compared rates of edentulousness in their 560 adults with ID with (asymptomatic) population data (n=2547) on this issue. The results were pretty worrying as "rates of edentulousness were consistently higher in the ID cohort" across various different age ranges: "9% vs. 1% aged 25-34 years; 22% vs. 2% aged 35-44 years; 39% vs. 7% aged 45-54 years; 41% vs. 18% aged 55-64 years; and 76% vs. 34% aged 65-74 years." Researchers also concluded that edentulousness was quite a bit more likely in those described as having "severe IDs".

When it came to other factors outside of ID severity that might be related to edentulousness, a few issues were observed such as "taking antipsychotics" and "living in the most deprived neighbourhoods." Other variables such as the presence of a diagnosis of autism and "problem behaviours" were are told, did not reach the thresholds for 'sufficient evidence'.

Why is all this important you might ask? Well, for lots of reasons, not least that the Kinnear results potentially highlight the important (continuing) issue of health inequality in relation to learning (intellectual) disability (see here). Indeed, one of my first thoughts when I read the Kinnear results is that quite a few of those news reports about people with learning disabilities that have been seen down the years, show people missing teeth. I can't help thinking what such pictures do for a person and their self-esteem. Even worse, such findings further highlight how for some people with ID, the state of edentulousness is literally forced on them (see here) with little or no regard for the views of them or indeed their loved ones.

Such findings do suggest that organisations need to try harder when it comes to improving the oral health of those with ID. I'm minded to suggest that those people who have a history of poor diet, those who are prone to pica (eating non-edible objects), those who have bruxism (teeth grinding) and/or those who have a history of persistent vomiting should perhaps be afforded particular dental attention. The link with antipsychotic use? Well, I also think more needs to be done in this area. There is already some data on medicines affecting oral hygiene [2] among which antipsychotics seem to have a place. The hows-and-whys need a little more understanding outside of the suggestion of xerostomia (dry mouth). Despite also the lack of any significant link between 'problem behaviours' and edentulousness identified by Kinnear, I'd still like to see whether certain 'challenging behaviours' might be contributory to such a state (see here) and perhaps one reason why antipsychotics were prescribed in the first place?

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[1] Kinnear D. et al. Prevalence of factors associated with edentulousness (no natural teeth) in adults with intellectual disabilities. J Intellect Disabil Res. 2019 May 6.

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Constipation and autism is not an uncommon combination

For those who know (or think they know) anything about autism, the title of this post - "Constipation and autism is not an uncommon combination" - is unlikely to be new or novel. Indeed, I've talked again and again and again about how functional gastrointestinal (GI) symptoms are very well over-represented when it comes to a diagnosis of autism (see here for example).

Enter then two further recent articles - one from Bradley Ferguson and colleagues [1] and one from María José Penzol and colleagues [2] - which further add to the evidence base in this area. Both papers are open-access, so please peruse at your leisure. The long-and-short of them can be quickly summarised:

• The Ferguson paper set out to examine the "relationships among GI [gastrointestinal] problems, problem behaviors, and internalizing symptoms in a sample of 340 children and adolescents with ASD [autism spectrum disorder]." Caregivers/parents reported on their child's GI issues. Bottom line: "The majority of the sample experienced constipation (65%)." Various other functional GI issues were also reported.
• The Penzol paper "reviewed the medical records of all patients admitted to the Comprehensive Medical Program for ASD (AMITEA) at Gregorio Marañón University General Hospital from January 2012 to December 2015." They analysed records for nearly 850 patients diagnosed with ASD. Their data were collected and transcribed by physicians including the "presence of fGID [functional gastrointestinal disorders] (gastrointestinal reflux, aerophagia, functional diarrhea, functional constipation, functional abdominal pain, cyclic vomiting)." Bottom line: "At least one fGID was present in 30.5% of patients, constipation being the most prevalent (47.4% of fGID patients)." They also observed that GI issues *seemed* to be related to the presence of intellectual (learning) disability, sleep issues and behavioural problems. These are not novel associations (see here and see here).

Of course there are strengths and weaknesses to those studies. No-one would dispute the fact that these are not perfect data. But, set within the context of a mountain of peer-reviewed science suggesting that something like constipation is over-represented when it comes to a diagnosis of autism, the collected results add a further layer of evidence. They also ask the question 'why', why oh why have we not got a greater handle on how to successfully treat/manage such symptoms?

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[1] Ferguson BJ. et al. The Relationship Among Gastrointestinal Symptoms, Problem Behaviors, and Internalizing Symptoms in Children and Adolescents With Autism Spectrum Disorder. Front Psychiatry. 2019 Apr 9;10:194.

[2] Penzol MJ. et al. Functional Gastrointestinal Disease in Autism Spectrum Disorder: A Retrospective Descriptive Study in a Clinical Sample. Front Psychiatry. 2019 Apr 10;10:179.

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Estimated autism prevalence in Northern Ireland: 3.3% for 2018-2019

The BBC news headline reading "Autistic children in NI schools trebles in a decade" provides the blogging fodder today.

NI refers to Northern Ireland, and the news report relates to the publication of further findings from the Department of Health in NI [1] on the topic of autism prevalence among school-aged children.

I've covered the NI 'autism in school children' figures for quite a few years on this blog (see here and see here). The stats have gone from 2.3% in 2015/2016 to 2.5% in 2016/2017 to 2.9% in 2017/2018 to the most recent figures of 3.3% in 2018/2019. The report and news coverage focus on how that recent 3.3% figure compared with 1.2% back in 2008/2009. That's quite a shift in the space of just a decade.

A few details are worthy of further mention. First, Northern Ireland seems to be taking a bit of a lead in collecting information about rates of autism in school-aged children (see here). Indeed, many of the 'home countries' making up the United Kingdom (UK) are starting to ask the questions that England, unfortunately, is seemingly not yet asking (see here).

Second, we are told that: "The increase in prevalence of children with autism can be attributed to an annual average increase in the number of children identified with autism of 12% between 2009/10 and 2018/19, against a background of a relatively static school population." This means that the rates of autism in school-aged children are not simply increasing because the school population as a whole is increasing. Indeed, with other not-so-long-ago chatter about long waiting lists for assessment in places like Northern Ireland (see here), one could argue that the current figures are an under-estimate.

Third, with regards to the sex ratio (boys:girls), the 2018/2019 figures suggest that "5.1% of males were identified with autism compared to 1.5% of females." The same figures a decade ago (2008/2009) were 1.9% and 0.4% respectively. I don't however necessarily agree with the: "Autism could therefore be considered to be an extreme of the normal male profile" sentiments expressed by the author to account for this difference but...

Fourth, the rate of the increase across the decade (2008/2009 compared with 2018/2019) was present in every school year. The author focuses in on the fact that nearly 4% of those in Year 6 (the end of primary school) were "identified with autism". He also mentions that most identification of autism in school is occurring when children are aged between 5 and 10 years old. Primary school, it seems, is an important time for the identification of autism.

Fifth: something approaching grading a child for autism 'severity' is also discussed. I know 'severity' is still a contentious issue (someone actually suggested 'severe autism' should be replaced by 'profound autism' which sounds rather sensible). Special educational need (SEN) assessment is a process via which a child's needs are graded. More details about this process applied to Northern Ireland can be found here. SEN stage 4 and SEN stage 5 indicate that a child requires support from school but also that "the education authority shares responsibility with the school." Nearly two-thirds of children identified with autism were at SEN stage 5. This was however down from previous years with the main 'growth' being among those who were gauged at SEN stage 2 and stage 3. The authors caution that such figures are only a snapshot (children can move up and down the SEN stages for example).

Whichever way you cut it, the recent figures out of Northern Ireland show the increasing trend for autism in school-aged children (see here). We can add such figures to those which have recently come out of the United States (see here and see here), Canada (see here) and various other parts of the world. We can quibble about the old 'better awareness' arguments and even diagnostic switching as being primary causes of the increase. I personally do not believe that such explanations even come close to the final reasons for the increase in cases that have been noted and continue to be seen (see here). What I do know is that further finance and resources are required to meet the often complex needs of these children and young adults to allow them to reach their potential.

And minus any emotive language (i.e. tsunami), let's remember that children turn to adults, and many of these children will require on-going help and support into their later years. The question is: are we prepared?

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[1] Waugh I. The Prevalence of Autism (including Asperger Syndrome) in School Age Children in Northern Ireland 2019. Northern Ireland Department of Health. 2019. May 10.

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Early Autism and Developmental Disabilities Monitoring says autism prevalence is still rising...

"The overall ASD [autism spectrum disorder] prevalence was 13.4 per 1,000 children aged 4 years in 2010, 15.3 in 2012, and 17.0 in 2014 for Early ADDM [Autism and Developmental Disabilities Monitoring] sites with data for the specific years."

So said the surveillance summary published by Deborah Christensen and colleagues [1]. Those of you who follow the US ADDM initiative (see here) will already know about the aims of this "group of programs funded by the CDC" looking at the (estimated) autism numbers, changes to the numbers and the impact of the numbers on various communities. Through initiatives like the ADDM, we already know that the estimated prevalence of autism in 8-year olds living in the United States is round about 1 in 59 (see here) and that the estimate continues to grow for pretty much every surveillance year examined. We are also starting to find out about how the change to DSM-5 from DSM-IV is likely to/not to impact on future figures (see here). And hopefully, at some point, we might have some further data on what happens to autism past childhood (see here) from such an initiative.

The Christensen paper adds another tier to the knowledge being acquired as per their analysis of the (estimated) prevalence rate of autism in 4 year olds "whose parents or guardians lived within designated sites." Those sites were: Arizona, Colorado, Missouri, New Jersey, North Carolina, Utah, and Wisconsin. The Early ADDM initiative does not cover the same area as its big brother/sister ADDM but "is conducted in two phases using the same methods and project staff members as the ADDM Network." Those phases include first "reviewing and abstracting data from children’s records, including comprehensive evaluations performed by community professionals" and then a second phase involving "a review of the abstracted evaluations by trained clinicians using a standardized case definition and method." DSM-IV criteria covers most of the time points examined but: "For 2014 only, prevalence estimates based on surveillance case definitions according to DSM-IV-TR and the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) were compared."

Results: as per the opening sentence of this post, the overall (estimated) autism prevalence across all sites for autism in 4 year olds was on the increase between 2010 and 2014. That's not to say that there weren't differences between the various sites - New Jersey, a favourite autism prevalence site (see here) showed the highest prevalence: 19.7, 22.1, and 28.4 per 1,000 for 2010, 2012 and 2014 respectively - but overall the prevalence rate was increasing not decreasing.

There were a number of other important points raised in the Christensen findings. So: "Among four sites with ≥60% data on cognitive test scores (Arizona, New Jersey, North Carolina, and Utah), the frequency of co-occurring intellectual disabilities was significantly higher among children aged 4 years than among those aged 8 years for each site in each surveillance year except Arizona in 2010." I don't think I need to say much more about that. Also: "The overall prevalence estimate using a DSM-IV-TR case definition was approximately 20% higher than the prevalence estimate based on DSM-5 criteria." Again, I don't think too much more discussion is needed on this point aside from saying that for 4-year olds, the switch to DSM-5 might have made more of a difference than for 8-year olds. Indeed in comparison to the Wiggins data [2] based on 8-year olds where "46.0% children met both DSM-IV-TR and DSM-5 surveillance status, 44.0% met neither the DSM-IV-TR nor DSM-5 surveillance status, 4.0% met DSM-IV-TR status, but not DSM-5 status, and 6.0% met DSM-5 status, but not DSM-IV-TR status of ASD" the Christensen data showed something a little different: "Among 1,237 children who met the surveillance case definition for either DSM-IV-TR or DSM-5, 974 (78.7%) met both case definitions, 234 (18.9%) met the DSM-IV-TR but not the DSM-5 case definition, and 29 (2.3%) met the DSM-5 but not the DSM-IV-TR case definition." Perhaps more study is required on the diagnostic changes?

What's more to say? Well, one of the authors - Walter Zahorodny - kinda said it all in a media comment: "There’s no letup. I really don’t understand why the rate is going up in this way." So maybe the next question, a question that really should have been examined a long, long time ago, needs to be 'Why?' rather than just a continual chain of studies saying autism prevalence is increasing...

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[1] Christensen DL. et al. Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 4 Years - Early Autism and Developmental Disabilities Monitoring Network, Seven Sites, United States, 2010, 2012, and 2014. MMWR Surveill Summ. 2019 Apr 12;68(2):1-19.

[2] Wiggins L. et al. Comparison of autism spectrum disorder surveillance status based on two different diagnostic schemes: Findings from the Metropolitan Atlanta Developmental Disabilities Surveillance Program, 2012. PLoS ONE. 2018; 13(11): e0208079.

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"Autism prevalence in China is comparable to Western prevalence" But is it really?

I was intrigued by the findings reported by Xiang Sun and colleagues [1] whose paper is the source material for the quote heading this brief post: "Autism prevalence in China is comparable to Western prevalence."

Intrigued because the idea that the prevalence of autism - in school-aged children - hovers around 1 in 100 (1%) in the Western world is still being banded around, even when data is being produced suggesting that rates are actually increasing well beyond the 1% mark in recent times (see here and see here).

Don't get me wrong, I am impressed with the Sun paper and the significant efforts and work that went into their study to look at "autism prevalence (mainstream and special schools) in Jilin City, and mainstream school autism prevalence in Jiamusi and Shenzhen cities" in China. Impressed because of the numbers involved, the 3-stage process undertaken (screening, clinical assessment, research diagnostic assessment) as part of the study and also because the data adds to a growing volume of other studies looking at autism in China (see here and see here for examples) and nearby areas (see here).

I'm not going to bore you with any more of my musings on this paper and issue. Suffice to say that the 1% statistic is old and increasingly out of touch with the current reality of autism in many, many different nations...

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[1] Sun X. et al. Autism prevalence in China is comparable to Western prevalence. Molecular Autism. 2019; 10: 7.

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DSM-IV vs DSM-5 criteria for autism continued

It's another 'DSM-5 autism' post (see here) from me today as the findings reported by W. Jason Peters & Johnny Matson [1] caught my attention on a topic that has been and remains pretty important: what happened to the rates of diagnosed autism when clinicians switched from the DSM-IV to DSM-5?

DSM-IV and DSM-5 represent versions of the Diagnostic and Statistical Manual of Mental Disorders, one of two manuals containing standardised criteria for diagnosing various behavioural and psychiatric labels. Autism is included in the DSM (and has been for a while). As with various other labels, the refinements to the diagnosis of autism that came with the introduction of the DSM-5 have the been the source of some speculation as to the potential impact on the rates of diagnosed autism.

The data produced so far have been a little bit mixed as to whether more, less or the same number of people would reach diagnostic cut-off points under DSM-5 compared with the application of the DSM-IV criteria (see here and see here) but perhaps with a slight inclination towards DSM-5 being more restrictive (also including a separate catch-all category called social (pragmatic) communication disorder (SCD) (see here)).

And so it was with the Peters/Matson findings, as we are told that: "Fewer individuals met criteria according to DSM-5" based on their cohort of infants and toddlers. The caveat? Well: "individuals with higher levels of symptoms were more likely to meet criteria for both versions [DSM-IV-TR and DSM-5] as compared to either alone" which kinda stands to reason. Indeed other papers recently published [2] pretty much said the same. The conclusion: "results suggest that there are meaningful differences in how DSM criteria may apply to individuals with an ASD [autism spectrum disorder]."

And, since I'm on the topic of what the DSM-5 did or did not do to autism diagnoses, a timely systematic review and meta-analysis from Kulage and colleagues [3] also adds something to the conversation: "Findings suggest smaller decreases in ASD diagnoses compared to earlier reviews."

End of line.

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[1] Peters WJ. & Matson JL. Comparing Rates of Diagnosis Using DSM-IV-TR Versus DSM-5 Criteria for Autism Spectrum Disorder. J Autism Dev Disord. 2019. Feb 27.

[2] Wiggins LD. et al. DSM-5 criteria for autism spectrum disorder maximizes diagnostic sensitivity and specificity in preschool children. Soc Psychiatry Psychiatr Epidemiol. 2019 Mar 8.

[3] Kulage KM. et al. How has DSM-5 Affected Autism Diagnosis? A 5-Year Follow-Up Systematic Literature Review and Meta-analysis. J Autism Dev Disord. 2019 Mar 9.

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"to [try and] advance the understanding of potential mechanisms underlying insomnia in adults with ASD"

The paper by Vanessa Hohn and colleagues [1] (open-access available here) provides the blogging fodder today and their findings in relation to the presence of insomnia as a "common source of distress in adults with autism spectrum disorder (ASD)."

Insomnia is essentially a regular problem in getting to sleep. It has a myriad of 'causes' ranging from uncomfortable sleeping conditions (bed, noise, temperature) to the influence of things like stress, depression and anxiety. Insomnia is no joke. Outside of the potential wide-ranging effects on physical and mental health [2] it puts a person at some heightened risk of all-manner of adverse outcomes [3].

As part of a suite of sleeping-related problems, insomnia is also no stranger to diagnostic labels like autism. With autism in mind, sleep problems that begin in childhood are pretty likely to carry over to adulthood. Nobody knows the precise reason(s) why those on the autism spectrum are more likely to experience sleep problems including insomnia. Some have speculated that the presence of autistic traits may be a risk factor for such sleeping issues (see here) but there is currently little detail regarding the bridge from core autism features to sleep problems. Others have observed an *association* between the presence of other somatic issues occurring alongside autism and sleep problems (see here and see here) but again, further clarity is needed on the hows-and-whys of any relationship and, importantly, what can be done to alleviate such issues.

Hohn et al started with the premise that: "Two characteristics of ASD could be relevant to insomnia complaints by hampering the entrainment of a circadian sleep-wake rhythm." They specifically talk about examining the link between sensory responsiveness and social skills in the context of insomnia in adults with ASD.

"Data were obtained from the Netherlands Autism Register (NAR), which is a longitudinal register including approximately 2000 individuals with ASD." Some 630 participants with autism were included for study, where "individual responses given to three measures of interest during an online survey in 2015 were analyzed." Those 'measures' were the Insomnia Severity Index (ISI), the Sensory Perception Quotient and the Autism Spectrum Quotient-28. The combined data were analysed.

Results: bearing in mind that this was a study exclusively including self-report from participants with autism - with no non-autistic control group - and one that relied on a single temporal snapshot of insomnia symptoms, one has to be a little careful with the findings. So: "The mean ISI score in the present sample was 9.50 (SD = 6.01), which is indicative of subthreshold insomnia and higher than means reported for the general population ranging between 1 and 7... but lower than values obtained from insomnia patients ranging between 17 and 20." Further, about half of participants scored in the "absence of insomnia" category with only around 20% of the group recording either moderate or severe insomnia. This tells us that, again according to self-report (and not using actigraphy for example), insomnia was not necessarily a widespread issue in this cohort but present in a not-significant number: about 1 in 5 people.

Next: "Primary analyses revealed that each of the covariates had a significant impact on the ISI total score." What this means is that biological sex, gender and medication use potentially played a role in insomnia. Women participating in the study tended to score higher on the ISI than men, and those aged 45-65 also seemingly showed more of a tendency towards insomnia. I don't think anyone would be really surprised with the idea that age and insomnia might be connected [4].

Some further statistical analysis of their results led researchers to opine on: "positive associations of insomnia severity with general and visual sensory hyper-reactivity and with impairment of social skills." I'm not too au fait with the specifics of the statistical modelling technique used by the authors - hierarchical multiple linear regression analyses (HMLR) - but can see what they did and how they did it, including "controlling for confounding effects of covariates" such as "medication, biological sex, intelligence, and age" (as previously mentioned). That being said, I'll draw your attention to some other conclusions reached by the authors: "The rather small effect sizes reported in the present study suggest that other factors not assessed in this study contribute to the emergence and persistence of sleep problems in adults with ASD."

The Hohn study does add something to the literature on sleep difficulties being experienced by quite a few people (children and adults) on the autism spectrum. I'm not overly convinced that they've stumbled upon evidence that core autistic features such as social skills problems and sensory issues are necessarily central to insomnia in their cohort but am willing to concede that they might play a role. Personally, I'd be inclined to go back to that data on 'comorbid' issues like gastrointestinal (GI) problems (see here) or breathing issues like apnoea (see here) as being something to explore further; also with the assumption that such issues are potentially 'treatable' and could have an important knock-on effect for something like insomnia and other sleep issues with autism in mind...

Oh, and don't forget the molecular handyperson that is melatonin and it's potential role in all of this (see here and see here). That and other potential avenues of research/clinical interest (see here)...

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[1] Hohn VD. et al. Insomnia Severity in Adults with Autism Spectrum Disorder is Associated with sensory Hyper-Reactivity and Social Skill Impairment. J Autism Dev Disord. 2019 Feb 9.

[2] Fernandez-Mendoza J. & Vgontzas AN. Insomnia and its impact on physical and mental health. Curr Psychiatry Rep. 2013;15(12):418.

[3] Garbarino S. et al. Insomnia is associated with road accidents. Further evidence from a study on truck drivers. PLoS One. 2017;12(10):e0187256.

[4] Foley DJ. et al. Sleep complaints among elderly persons: an epidemiologic study of three communities. Sleep. 1995 Jul;18(6):425-32.

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Canada and the prevalence and incidence rates of autism (again)

"During the period from 2004 to 2015, both prevalence and incidence rates of diagnosed ASD [autism spectrum disorder] in preschoolers and toddlers residing in Manitoba increased significantly."

That was the conclusion reached in the paper by Amani Hamad and colleagues [1] who undertook analysis of the Manitoba Population Research Data Repository to examine "the annual prevalence and incidence rate of ASD between 2004 and 2015 in children aged 1 to 5 years residing in Manitoba." Such research follows quite a longstanding theme, where Canada is quietly producing some important information about the growth of autism across its population (see here and see here).

I mentioned two words in the title of this post - prevalence and incidence - which perhaps need further explanation. Prevalence refers to the number of existing cases of a condition / disorder / disease, typically expressed as a proportion of a population. Incidence is more about the number of new cases of a condition / disorder / disease during a specific period of time. Hamad et al reported data on both measures, where "1685 ASD cases were diagnosed between 2004 and 2015."

So: "The crude ASD prevalence increased from 0.46% in 2004 to 0.97% in 2015" and "The crude incidence rate increased from 0.16% in 2004 to 0.39% in 2015." These combined findings illustrate that the number of cases of diagnosed autism in young children in Manitoba over the period of 2004 and 2015 was not static; more and more people were being diagnosed, and with an increasing rate of diagnosis.

What's more to say? Well this data puts another nail in the coffin to the old 'autism isn't increasing' argument that has slowly fizzled out over the past decade or so. Autism diagnoses are on the increase; and as per the Hamad focus - preschoolers and toddlers - at least some of the increase is in the young and not just older children and adults who might have 'slipped through the diagnostic net'. Next questions: why and what? Why is autism still on the increase? What factors are driving the increase? And please, enough with the 'increasing awareness' dogma on this question...

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[1] Hamad AF. et al. Annual trends in prevalence and incidence of autism spectrum disorders in Manitoba preschoolers and toddlers: 2004-2015. Can J Public Health. 2019 Feb 11.

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Autism diagnoses in Northern Ireland: the only way is up

"Autism diagnoses in NI [Northern Ireland] children up by more than 100%" was the headline on the BBC news website recently. It followed a Freedom of Information (FOI) request from the national broadcasting corporation here in Blighty to "all five of Northern Ireland's health and social care trusts... [covering] the period between 2013-14 and 2017-18."

The scale of the issue facing the various health and social care trusts when it comes to the significant 'growth' in both received and 'awaited' autism diagnoses is not to be under-estimated. Indeed, the BBC really needn't have gone down the FOI route because Northern Ireland already collects and quite publicly publishes quite a lot of information about autism in children under their geographical jurisdiction (see here and see here).

The details? Well, if you ever you needed proof that autism is still on the increase among children and young adults, the data provide it: "In total 2,345 children under 18 were diagnosed as autistic last year, compared with 1,047 five years previously." And other details are important too: "In keeping with trends that show males are more likely to be diagnosed, almost three times more boys than girls were found to be autistic in the five years."

What else is there to say? Some old and tired arguments about 'increasing autism awareness' being behind the increase in cases being diagnosed (and awaiting diagnosis and/or assessment) is reported in the BBC piece. About 20 years ago I would have agreed with this but not so much now; we are in an age of autism awareness and have been for several years. Perhaps it's time to start thinking about what factors outside of awareness might also be contributing to the substantial increase? Y'know, entertain the idea that some of the increase may well be a real increase (see here) and start thinking about what factors might be important there?

And with growing numbers of children and young adults being diagnosed with autism, so more current- and future-planning is required to ensure that their health, educational and social needs are met. It sounds great in theory but the reality is that service provisions and resources are already struggling and increasingly scarce. Indeed, a recent article on autism from across the Pond titled "The Coming Care Crisis as Kids With Autism Grow Up" hits the nail right on the head about how 'strained' many systems currently are. And that's without even taking into account what's going to happen 5 or 10 years down the line when more and more autistic children turn into autistic adults. Action is required, like now.

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Regression and autism: "The regression group was significantly more functionally impaired..."

The quote forming part of the title of today's post - "The regression group was significantly more functionally impaired..." - comes from the findings reported by Lucy Thompson and colleagues [1] (open-access available here). It continues something of an important theme in autism research circles whereby regression, as in a regression of previously acquired skills, is being seen as important not just for a few but for many (see here).

There were a few aims to the Thompson study such as establishing "the relative prevalence of regression in autism" and "possible predictors, mediators and moderators of regression in autism, including pre- and perinatal factors." The data for the study were derived from "two community-based cohorts" in Sweden totalling just over 300 participants (children) diagnosed with an autism spectrum disorder (ASD) who were observed over two different time points (T1 and T2 2 years later). Another important detail is mentioned by Thompson et al: "Given the lack of previous systematic representative studies in the field, our study sets out to be descriptive rather than hypothesis-driven." Figures and details on regression in the cohort(s) were obtained via specific questioning on this topic "defined as loss of expressive language skills (loss of 5 or more words that had been used communicatively) in connection with the onset of autism." This data was also combined with other medical records information to determine 'consistency'.

Results: "Just over 20% (62/303) of the combined sample of children had regressive autism." That's 1 in 5 children with autism experiencing some kind of regression in relation to language skills. When looking at those who regressed (n=62) compared with those with no regression (n=241), a few details emerged: "Those with regressive autism had a younger age when they first walked... had a more severe language impairment at T1... and more often intellectual disability... [and] lower mean VAB [Vineland Adaptive Behaviour Scales-II] scores." Also: "Severity of autism was higher in the regressive group, with a higher proportion of children with autism... (as opposed to autistic-like condition)."

This is important data. It kinda tallies with other studies of regression accompanying autism suggesting that those who regress tend to have a more 'severe' form of autism with accompanying learning (intellectual) disability. The diagnostic issues - as in more likely to be diagnosed with Kanner's autism rather than other diagnoses - similarly ties in with other findings.

Caveats? Well, a few: "We have chosen to focus on language regression specifically (rather than social, play or motor regression) as communication is by far the most common skill to be lost or diminished in regressive autism." That being said, regression accompanying autism seems to take many, many forms and does not always just mean a loss or partial loss of vocal communication (see here).

Also: "There was also a similar level of maternal disease in pregnancy in the regressive and non-regressive groups, suggesting that prenatal exposure via maternal disease does not seem to be a key feature in the development of regressive autism." I have to question why the authors stuck to looking at just pre- and perinatal factors as possibly being *linked* to regression when regression is likely to occur quite some time after such a developmental window. Surely it would have made more sense to ask a few further questions about the timing of regression - "The average age at regression was 20.13 months... with 54 children (88.5%) showing regression by the age of 24 months" - and whether one or more event might have proceeded such regression in a similar time frame. Y'know whether infection might be a feature (see here and see here for examples) or whether other events might require further investigation (see here). I know this might take such research down some uncomfortable paths, but temporality is surely an important factor for some regression in some cases of autism? Or am I being too unreasonable?

I might also advance the idea that the time to start asking questions about the biology of regression accompanying autism is fast approaching. We've already had some clues in the recent (at the time of writing) peer-reviewed research literature (see here) but lots more needs to be done in this area. Are there important genetic and/or epigenetic variables to consider? Do mitochondrial issues play a role in some regressive autism (see here)? We just don't know enough yet. And yes, this does mean also asking about whether regression in behaviour or cognitive skills was also accompanied by any changes to somatic variables too (see here).

And then there is another question to ask/answer: does regression mean that certain 'therapeutic' options might be particularly useful? I'm thinking back to some research a few years back talking about corticosterioid therapy *potentially* being indicated for some cases of regressive autism (see here). No, I'm not making any medical or clinical claims or giving any advice on such an issue. Merely mentioning that regressive autism needs to be more of a research priority than it currently is. To quote Thompson and colleagues again: "Children with a regressive developmental trajectory, with or without autism, always need a careful neuropediatric work-up to investigate possible neurological disorders that may lead to developmental regression, taking into account possible treatable conditions." Who would argue with that?

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[1] Thompson L. et al. Autism With and Without Regression: A Two-Year Prospective Longitudinal Study in Two Population-Derived Swedish Cohorts. J Autism Dev Disord. 2019 Feb 4.

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DSM-5 autism is "largely comparable to" to DSM-IV-TR autism

"Merry New Year". Welcome back to Questioning Answers in 2019. So let's continue.

The quote heading this post comes from the findings reported by Lisa Wiggins and colleagues [1] and their research aiming to "replicate agreement between surveillance status based on DSM-IV-TR criteria and DSM-5 criteria for ASD [autism spectrum disorder]." This authorship group have some interest in the description of autism across the DSMs (Diagnostic and Statistical Manual of Mental Disorders) as a function of their involvement with the United States CDC and their other, quite recent publication, talking about the national US autism prevalence estimates in 8-year olds for 2014 (see here).

As well as arriving at the conclusion that 1 in 59 children aged 8-year old in the United States *might* have autism [2] (still potentially an underestimate according to other recent figures), their latest prevalence paper also, for the first time, introduced the DSM-5 to the Autism and Developmental Disabilities Monitoring (ADDM) Network. Previously, the DSM-IV was top (diagnostic) dog, but with the publication of the DSM-5 (see here) there was a new sheriff in town. And as the DSM-5 started to be utilised more and more widely in diagnostic circles, so the CDC autism estimating teams had to start taking this into account in their musings...

Wiggins et al relied on data for "8-year-old children who had health and education records reviewed for ASD surveillance in metropolitan Atlanta, GA in the 2012 surveillance year as a part of the Metropolitan Atlanta Developmental Disabilities Surveillance Program (MADDSP)." As per the aims and objectives of the MADDSP - "estimates the number of children with selected developmental disabilities in metropolitan Atlanta" - autism is one of the diagnoses included in the surveillance program. DSM-IV-TR criteria for autism were applied to the health and education records of a cohort of children to see if diagnostic thresholds were met. Importantly too we are told that: "a previous ASD diagnosis was not sufficient evidence to confirm DSM-IV-TR surveillance case status." Alongside: "A DSM-5 coding scheme for ASD surveillance was developed by an independent body of ADDM-affiliated experts and then adapted and refined by a CDC-led clinical workgroup." Application of this DSM-5 coding scheme was similarly used on those education and health records data and results were collected and compared.

"Similar to ADDM data reported for the 2014 surveillance period, we found substantial agreement between DSM-IV-TR and DSM-5 surveillance status of ASD in a sample of records reviewed for the 2012 surveillance period." The figures in a little more detail: "46.0% children met both DSM-IV-TR and DSM-5 surveillance status, 44.0% met neither the DSM-IV-TR nor DSM-5 surveillance status, 4.0% met DSM-IV-TR status, but not DSM-5 status, and 6.0% met DSM-5 status, but not DSM-IV-TR status of ASD." The importance of this data is what the quote heading this post talked about: DSM-5 autism is "largely comparable to" to DSM-IV-TR autism. So when the ADDM eventually makes the transition over to DSM-5 derived autism data only, it means that all those years of DSM-IV diagnosed autism are still very much relevant (and can be used as a comparator) in a historical context.

But... the authors do mention about how some other studies have observed that: "fewer children meet DSM-5 criteria for ASD than DSM-IV-TR criteria for ASD in similar service settings" (see here and see here). This requires quite a bit more investigation; in particular how "record-review surveillance [such as that utilised by Wiggins et al] relies on information contained in surveillance records and does not include an in-person evaluation of the child." As I've indicated in my very critical musings on armchair diagnosis of historical persons (see here for an extreme example), there is absolutely no substitute for talking to and directly observing a person who has been referred for a diagnostic assessment. None. I've also previously suggested that another related label that crops up near to the DSM-5 description of autism - social (pragmatic) communication disorder (SCD) - might also need some research attention too. Indeed, I wonder if the ADDM might eventually start reporting on autism and SCD separately...

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[1] Wiggins L. et al. Comparison of autism spectrum disorder surveillance status based on two different diagnostic schemes: Findings from the Metropolitan Atlanta Developmental Disabilities Surveillance Program, 2012. PLoS ONE. 2018; 13(11): e0208079.

[2] Baio J. et al. Prevalence of Autism Spectrum Disorder Among Children Aged 8 Years — Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2014. Morbidity and Mortality Weekly Report (MMWR). 2018; 67(6): 1-23.

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Estimated one in 69 children aged 8 years old with autism (not one in 68) in 2012

"On June 5, 2018, the authors informed MMWR [Morbidity & Mortality Weekly Report] about a number of inadvertent errors throughout the report that resulted from reporting of autism spectrum disorder cases among persons who did not live in the geographic surveillance area."

So said a brief note [1] recently listed in the CDC Morbidity & Mortality Weekly Report (MMWR) concerning an important article published in 2016 [2] that described the estimated autism prevalence rate in the United States in 2012 for children aged 8 years old.

The original paper by Deborah Christensen and colleagues [2] was fodder for this blog at the time of publication (see here), with their estimated figures for 2012 (one in 68) showing a potential plateauing of the autism estimated prevalence rate in the US (see here for some discussion on the previous figures for 2010). The 'plateau' proved to be short-lived; as more recent figures published this year (2018) for the surveillance year 2014 once again showed the continuation of the upward trend (see here) in the childhood autism prevalence rate, now up to an estimated 1 in 59 children. Other figures have suggested even 1 in 59 is likely an understatement (see here).

Christensen and colleagues have republished their 2016 paper [3] showing 'where they went wrong'. It's not a wildly different article from their original publication and to a large extent, does not alter the underlying figures in any hugely significant way: 'one in 68' is replaced by 'one in 69'. Looking at the tables accompanying the Christensen republication, I was first drawn to Table 2 showing the: "Estimated prevalence* of autism spectrum disorder [ASD] among 1,000 children aged 8 years, by sex —Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2012." Under the column labelled "Total no. with ASD" it looks like a few participating States had corrections. Arkansas in particular stood out; their total going from 170 with ASD down to 125. Their estimated autism prevalence subsequently dropped from 12 per 1,000 children (aged 8) to 8.8 per 1,000. Other States showed a correction in the opposite direction. New Jersey (which has had an important role to play in the CDC estimates) showed a slight increase (of 3 children) in their "Total no. with ASD" similar also to Missouri.

There's little more to say about the Christensen correction aside from reiterating that: (a) the CDC statistics citing figures like 'one in 69' or more recently 'one in 59' are estimates, and (b) how and what data you include for counting is going to have an important bearing on what (estimated) prevalence rate you arrive at. By saying all that, I've not changed my view that we are witnessing something of at least a partial 'real' increase in cases of autism (see here and see here and see here) as older 'better awareness' and 'diagnostic substitution' arguments become less and less relevant as the numbers (estimated) climb ever higher. And aside from keeping on asking 'why?' the powers-that-be should be putting a lot more money and resources into the services that will inevitably be required, to ensure that children and adults on the autism spectrum aren't (societal) disadvantaged by their diagnosis.

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[1] No authors listed. Correction and Republication: Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years - Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2012. MMWR Morb Mortal Wkly Rep. 2018 Nov 16;67(45):1279.

[2] Christensen DL. et al. Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years--Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2012. MMWR Surveill Summ. 2016 Apr 1;65(3):1-23.

[3] Christensen DL. et al. PPrevalence and characteristics of autism spectrum disorder among children aged 8 years — Autism and Developmental Disabilities Monitoring Network, 11 sites, United States, 2012. MMWR Surveill Summ. 2018 Nov 16;65(13):1-23.

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One more time... (roughly) 1 in 40 children with parent-reported autism in the US

Consider this short post an extension of another recent entry on this blog talking about new data observing that the estimated autism prevalence rate (parent-reported) is around 1 in 40 children in the United States (US) (see here). That entry was based on the paper by Michael Kogan and colleagues [1] and their examination of data "using the 2016 National Survey of Children's Health (NSCH)" initiative.

Enter then another piece of research published little over a week after the Kogan study from Guifeng Xu and colleagues [2] which concluded that: "In a large, nationwide, population-based study, the estimated prevalence of ever-diagnosed ASD [autism spectrum disorder] was 2.79% among US children in 2016." In case you were wondering, 2.79% or 2.8% roughly translates as 1 in 36 children. Xu and colleagues, I might add, are no strangers to prevalence studies on childhood neurodevelopmental disorders (see here and see here).

Both these studies have attracted some media attention (see here and see here) mainly because they show a prevalence rate quite a bit higher than the recent CDC (estimated) autism prevalence figures - 1 in 59 8-year olds - published earlier this year (2018) (see here). Those media reports also seem to make quite a big deal of the 'parent-reported' nature of the figures (both derived from the NSCH initiative). As I mentioned in my last discussion of the Kogan paper, a quote from the lead author Michael Kogan is important in the context of those parent-report 'issues' that some people seem to have: "We know that in terms of having a major condition like autism, parents are usually pretty good reporters compared to medical records." Indeed they are.

Other details to add? Well, the Xu paper also reported on "state-level prevalence of ASD in the United States." They observed variations in the reported prevalence of autism (ASD) across the different states: "The state-level prevalence varied from 1.54% (95% CI, 0.60-2.48) in Texas to 4.88% (95% CI, 2.72-7.05) in Florida." Little explanation is given about such a discrepancy in their paper and so further research is implied.

Also: "Among those who had ever been diagnosed as having ASD, 92.79% (95% CI, 90.19-95.39) reported currently having ASD." This is interesting. Allowing for the fact that the diagnosis of autism or ASD is often more of an art form than a scientific endeavour, I did wonder whether the loss of about 8% of children who were previously diagnosed with autism but did not report currently having autism might overlap with the 9% figure with regards to the term 'optimal outcome' (see here). Y'know, the ever-growing body of peer-reviewed research that seems to suggest that for some people, a diagnosis of autism is not necessarily 'lifelong' (see here) (even if 'optimal outcome' is not necessarily the best phrase to use). Again, further research is implied.

For now however, we can conclude that there is : "a relatively high prevalence of ASD among US children" mirroring that in other parts of the world (see here for example). We really need to be asking questions like 'why?' and also 'are the relevant mechanisms in place to ensure that money, resources and services are directed towards this growing population?'

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[1] Kogan MD. et al. The Prevalence of Parent-Reported Autism Spectrum Disorder Among US Children. Pediatrics. 2018 Nov 26. pii: e20174161.

[2] Xu G. et al. Prevalence and Treatment Patterns of Autism Spectrum Disorder in the United States, 2016. JAMA Pediatrics. 2018. Dec 3.

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