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.
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.