2025: the year of plural autisms, folate chemistry and when curiosity about autism returned

Spectrum 2025: Year in review https://www.thetransmitter.org/spectrum/spectrum-2025-year-in-review/

A 'what happened in 2025' feature that covers the main elements of autism in 2025 including: (1) we're heading back to asking the questions of 'how and why?' about autism rather than falling back on some pseudo-religious neurobabble, (2) US policy on autism has been driving lots of focus particularly on folate chemistry - cerebral folate deficiency (CFD), folate receptor autoantibodies (FRAAs) and leucovorin (folinic acid) - and some autisms, and (3) the year that the plural autisms finally emerged into the mainstream. That last one is particularly close to my research heart: https://www.cambridge.org/core/journals/the-british-journal-of-psychiatry/article/abs/from-autism-to-the-plural-autisms-evidence-from-differing-aetiologies-developmental-trajectories-and-symptom-intensity-combinations/4D9B0B35DCF03FDBA4E001F7DC9B02D6

2025 has been a pivotal year for autism as the 'lack of curiosity' of the past few years (in some quarters) has given way to more people asking important questions. It's no longer about whether 'identity first language' trumps 'person first language' (indeed, whole swaithes of identity related stuff has been shown for what it really is) or whether other such meaningless word policing is important to many people's lives, but what can actually help people with autism and their parents/carers, particularly those with severe and/or profound autism. Indeed, mention of those words 'severe' or 'profound autism' is only going to accelerate as the old 'autism is autism' mantra dwindled further in 2025 and as 'people' or 'person' become primary, rather than their diagnostic label.

There's lots of hope for 2026 that things will continue at a similar pace.

Maternal autoantibody related (MAR) autism goes mainstream

"MARAbio Launches First-Ever Blood Test For Maternal Autoantibody Related Autism" https://www.marabio.com/test-launch

Woah. 

Just when you thought 2025 couldn't bring anything else to the world of the autisms (plural), a press release which was kinda expected but is now an actuality.

MAR autism - maternal autoantibody related autism - has been on the research menu for a while. Quite a few scientific papers have found it and indeed, found the specific autoantibodies (to foetal tissue) that seem to be pathogenic for risk of this type of autism. And it's not just testing either, as some science has talked about the ways-and-means to 'avert' the effects of those antibodies too and impact on offspring autism risk. This has been years in the making. 

"Commenting on the potential impact of this launch for providers and families, noted clinician and autism researcher Richard E. Frye, MD, PhD, said, "With MARAbio's test now available, particularly for those families already touched by autism, we now have access to meaningful insights into this particular and prevalent cause of autism, including the likelihood of MARA in future children. It's an exciting advancement that brings science and compassionate healthcare together in a truly impactful way."

It should perhaps be noted that the research into other types of autoantibodies - folate receptor autoantibodies - by Dr Frye and others has also been an achievement unlocked in 2025. Indeed, both these streams of research and now clinical practice, whilst so far distinct, point to a pivotal role for immune functions and their effects across quite a few autisms. And that should provide some important clues for future work on 'how and 'why' and what to do about it.

And yet more evidence for those plural autisms which is music to my research ears...

"It will recommend practical, evidence-based approaches to prevention and early intervention..."

Review launched into mental health, autism and ADHD services https://www.gov.uk/government/news/review-launched-into-mental-health-autism-and-adhd-services 

The offical government announcement on the review into mental health, autism and ADHD services launched by the UK Government today. It looks like the important issues to "look at rising demand for mental health, ADHD, and autism services and what is driving it" are actually being taken seriously. That sentence on action as well, around intervention and, dare I say it, prevention, is also quite the change of tack from previous administrations. 

Of course it all boils down the how much the various diagnoses are costing in terms of education, healthcare and social care and benefits given the massive rises in those diagnoses and what they mean for lots of different outcomes. For example, a childhood autism rate for 2024/2025 approaching 6% in Northern Ireland combined with the recent APMS data telling us that the adult autism rate in England has been static at 1% for nearly two decades is a case in point. It would be naive to think lack of money and lack of resources isn't the primary driving factors behind such a review given what this government has already tried to do when it comes to cutting costs. 

But an opportunity is an opportunity.

"My aim is to test assumptions rigorously and listen closely to those most affected, so that our recommendations are both honest and genuinely useful. We owe it to children and families, young people and adults to provide government with advice that is proportionate, evidence-based, and capable of improving people’s lives." 

I don't think anyone can really ask for more than that sentence from the head of this new review. Indeed it seemingly follows the changes to US policy particularly around autism, where people are actually starting to ask questions about 'how and why' rather than sticking with the usual babble (neuro) and other fluff that has contributed to some people not wanting to ask questions about important conditions which affect many peoples' lives.

"Autism (examined using ADOS) has remained stable in prevalence since 2007, at about one in a hundred adults (0.8%)."

"Autism (examined using ADOS) has remained stable in prevalence since 2007, at about one in a hundred adults (0.8%)." https://digital.nhs.uk/data-and-information/publications/statistical/adult-psychiatric-morbidity-survey/survey-of-mental-health-and-wellbeing-england-2023-24

Data released today (27th November 2025) from the Adult Psychiatric Morbidity Survey: Survey of Mental Health and Wellbeing, England, 2023/4.

It puts pay to the idea that there is any sort of equivalence in child and adult rates of autism (and that there ever has been). Said equivalent child autism rate is currently anywhere between 2-6% of school-aged children depending on what data you use.

We knew this of course, from the data from Tromans et al: e.g. Characteristics and primary care experiences of people who self-report as autistic: a probability sample survey of adults registered with primary care services in England https://pubmed.ncbi.nlm.nih.gov/39277196/ (based on self-report) and more.

It tells us, yet again, that the massive increase in autism prevalence is being driven by new childhood cases (autism is a childhood neurodevelopmental disorder so not really surprising). And also no, there aren't 'missing millions' of adults with undiagnosed autism as per what Adamou et al reported when they actually assessed adults who presented at clinic: Enhancing Adult Autism Diagnostic Pathways: The Role of Clinical Triage in Efficient Service Provision https://pubmed.ncbi.nlm.nih.gov/40363963/ (and proved that triage works).

So then, a question: what is causing huge numbers of children to present with and be diagnosed with autism? 

Well, only yesterday, some evidence that the words 'it's all genetic' are not a great explanation: e.g. As rates of ASD and ADHD rise, genetic contributions fall: Evidence for widening diagnostic criteria https://pubmed.ncbi.nlm.nih.gov/41292638/ which opens the door to issues like (a) widening diagnostic criteria and/or (b) environmental - non-genetic - factors 'causing' more autism. Or both?

Oh and keep in mind that despite the dogma, autism is not universally a lifelong condition for everyone e.g. https://pubmed.ncbi.nlm.nih.gov/31632036/ which may well partly explain why the adult autism rate is and has been so static for so many years...

Prenatal folic acid and multivitamin supplementation and offspring autism risk: umbrella-ified review

"Maternal prenatal folic acid and multivitamin supplementation are associated with a reduced risk of ASD [autism spectrum disorder] in offspring. These findings have important public health implications, suggesting that prenatal supplementation could help mitigate the risk of ASD in children." https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0334852

The results of an umbrella review that included 8 other systematic reviews or meta-analyses which themselves included over 100 studies which included several million mother-child pairs. In short, top tier evidence.

"Prenatal folic acid and/or multivitamin supplementation was associated with a 30% reduced risk of ASD in offspring (RR = 0.70, 95% CI: 0.62, 0.78; GRADE: highly suggestive). Subgroup analysis by supplement type showed that maternal prenatal multivitamin supplementation reduced the risk of ASD by 34% (RR = 0.66, 95% CI: 0.55–0.80; GRADE: highly suggestive), while folic acid supplementation was associated with a 30% reduction in ASD risk (RR = 0.70, 95% CI: 0.60–0.83; GRADE: highly suggestive)."

And yet again, folate metabolism and autism. 

The same folate metabolism and autism that is also US health policy now in terms of some autisms being potentially linked to cerebral folate deficiency (CFD) and/or folate receptor autoantibodies (FRAAs) meriting use of leucovorin (folinic acid). The difference being that in those areas - CFD and FRAAs - folic acid may not be the optimal supplement to use, as per why folinic acid (and perhaps even methylfolate) is instead being suggested for some children/adults with autism. Whether that might also translate into similar issues with folate metabolism for mums-to-be too as, being a risk factor for offspring autism, remains to be seen.

Nutritional factors being important to at least some autisms? Who'd have thunk that?

Folinic acid (leucovorin) and autism: what kept you?

A Closer Look at the Drug Trump Is Touting for Autism: https://www.wsj.com/health/wellness/autism-leucovorin-science-research-0a666a8d

As the dust settles from what has been quite a monumental week for autism policy over on the US side of the Pond, particularly the new guidance on the use of leucovorin (folinic acid) for some autisms, some important questions emerge... 

Science has known about the potential connections between some autisms and cerebral folate deficiency (CFD), those folate receptor autoantibodies and the usefulness of folinic acid for some autisms for a while. I talked about them back in 2012: Don't panic! Folate receptor autoantibodies and autism https://questioning-answers.blogspot.com/2012/01/dont-panic-folate-receptor.html So why did it take so long for such research to be government evaluated and considered worthy of such a move from 'bench to bedside'? What were previous administrations doing and what stopped this 'bench to bedside' move happening years ago?

I'm sure the answer is going to be complicated. Not least to include certain attitudes to autism (the autisms) from some certain quarters, what sorts of medicines are potentially indicated for said autisms (and whether there is monetary value attached to their usage) and the important need for as-near-as-possible solid science (particularly in the context of safety).

But it now appears there is more a 'pipeline' moving forwards, whereby similarly important biological mechanisms and related interventions can seemingly be quickly evaluated across the autisms. Indeed it again brings to mind the work on other medicines such as suramin and also the very promising results for CM-AT e.g. Pancreatic Replacement Therapy for Maladaptive Behaviors in Preschool Children With Autism Spectrum Disorder https://pmc.ncbi.nlm.nih.gov/articles/PMC10690476/ Also too, potentially important are the writings from the US FDA not so long ago about other intervention options for some autisms and the need for more controlled study e.g. Biological therapies need definitive randomized controlled clinical trials https://www.science.org/doi/10.1126/scitranslmed.adg2970 something that also seems to be a priority for the current US administration as older, less fruitful avenues of study will inevitably be replaced.

I think we have turned a corner in our understanding of the autisms and indeed, the desire to see safe and effective intervention options that help to remove at least some of the disability associated with the autisms. And where the US leads in policy around autism, other countries are sure to follow.