There's lots of true things in that post, and it's undeniable that there's been huge broadening of criteria and it's responsible for a lot of the growth in stats. The question is, is it responsible for all of it? To understand that we have to hold severity constant and compare across time.

A recent study tries to define "profound autism" as "nonverbal, minimally verbal, or IQ<50". They found a significant increase in US children aged 8 from 2000-2016 with profound autism. Non-profound autism increased much more, which makes sense given the broadening of criteria. The study is https://pmc.ncbi.nlm.nih.gov/articles/PMC10576490/

Anecdotally, any speech therapist with a long career will likely remark on a local increase of severe autism cases over the last 20-30 yrs. It's not as "skyrocketing" as ASD stats, but prevalence has likely increased substantially.

I wonder if perhaps the age when people become parents has an affect on this. Anecdotally, many of the people I know of my generation are having kids later than their parents and grandparents did. There's known correlations to different long-term health issues that we do know of that are related to the age of parents, so if there's a rise in average age of parenthood, it could be related?

Kinda spitballing here though.

Nah. It's been shown that older parents run significantly higher risk for all kinds of genetic and birth defects.

Male sperm begins to degrade sometimes around 30 iirc.

People having kids around 40 years old are significantly more likely to have offspring with a ton of issues. People are having kids much later, now.

This isnt my theory. It's been discussed at length and a google will give tons of info.

Don't want to deny that your question, is it responsible for all of it, is sill undecided, however this issue is _likely_ due to similar changes in societal factors.

The Mental Health Parity Act passed in '96, and another passed in '08[0]. Together this leads to a significant increase in to those with mental health issues being treated. So while broadening of criteria might not be to blame for what you're discussing, the broadening of mental health care coverage might be.

[0]: https://en.wikipedia.org/wiki/Mental_Health_Parity_Act#Issue... [1]: https://www.ajmc.com/view/the-mental-health-parity-act-10-ye...

> is it responsible for all of it, is sill undecided, however this issue is _likely_ due to similar changes in societal factors.

The changes in medical culture (over just 10y) are why my youngest was diagnosed but my oldest is not.

That study is at risk of the same effects of diagnostic rules, case-finding, service incentives, record linkage and diagnostic substitution as any other. So it can explain the increase shown here as well. That said, you're right, we don't know if there is within that an increase or not being masked. But it's very possible there isn't, or if there is, it's pretty small. Which wouldn't really mandate as much worrying as is happening now.

For me, the question might be, can we get the data in check? Don't want to go another 20 years and still not be able to know the real data because we kept changing the definitions, the rules around diagnosis, who is eligible to be diagnosed, the cost of diagnosis, etc.

my pet theory is that assortative mating concentrates autism. two people who are each slightly on the spectrum meet, they click (because their minds are compatible), get married and have children. the genetic factors involve get concentrated. after a few generations the effect gets really noticeable. it's easier for autistic people to meet, especially with easier travel, large cities and niches.

I'm not a biologist or a doctor, but I suspect that the reason for more people with profound autism is the fact that all developed countries have massively improved rates of saving fetuses in the premature birth events. If my hypothesis is true, it would mean that so called pro-life conservatives are practically causing increased rates of profound autism, by forcing people to save damaged embryos/fetuses. PS: in my limited circle of acquaintances, 2 out of 2 cases of such kids were caused by doctors saving the fetus with direct medical intervention. And according to one of the fathers of such kid, the more advanced countries are moving away from doing that universally to every mother.

Am I right in my reading of that study:

- in 2002, 26.9% of the ~2300 cases of autism were 'profound'

- in 2016, it was 24.3% of the ~4800 cases

I must have missed some stuff, but this doesn't seem hugely significant to me?

>any speech therapist with a long career will likely remark on a local increase of severe autism cases over the last 20-30 yrs.

Population growth.

are you saying the population of speech therapists is not growing proportionately to the general populace?

i have no opinion on whether population growth is a factor, but to make an observation of the growth of cases it wouldn't matter because the therapists probably know each other, so having more therapists in a locality would be included in the observation. there are more cases not because more people come to me, but because i know more therapists having cases.

> People who would never have survived childbirth or early childhood in previous generations are surviving nowadays at historically unprecedented rates.

I have seen studies that correlate c-section deliveries with a somehat significant increased chance of autism, so that would track. I was born by csection myself, and both myself and my mom would have died if that wasn't an option.

I've never been evaluated for and am not diagnosed with autism, but given the broadened DSM criteria, it's possible they would have tested me and labeled me with something like that if I had been a kid today. Instead they just settled on "speech disability" and put me in weekly speech therapy for all of elementary school. I'm not sure if having a permanent disability label on me from a young age would have been a good thing to be honest.

There seems to be a relationship here, as shown in this paper, https://pmc.ncbi.nlm.nih.gov/articles/PMC5837358/

I am skeptical of the idea that a CS itself produces any conditions for ASD. But it would make sense that those who would have otherwise died during child birth and survive are now likely to change present health demographics.

Honestly, a lot of autistic people are doing well in life, and in fact many are doing better than their neurotypical peers. Autistic traits need to be understood better because they provide better understanding of human cognition and its functionality.

In my case, I came out 2 weeks late and was little over 12lbs (~5.5kg) when I did. Apparently birth weight over 9.5 lbs is also correlated with higher rates of ASD. That would be my guess as to why c-sections show a correlation.

My First and Fifth are autistic. All births were full term.

1st 8lb. 2nd 8lb, 3rd 10.5lb, 4th and 5th 6.5lb ea (twins). None were c-section.

First 3 were home or birth center, last had to be hospital. My wife had good BMI for the start of each pregnancy.

I do not really understand what conclusion to draw from this.

A friend of mine has 8 childen and none are autistic. All were born at the hospital (this is where you give birth in France), all were notmal weight and so was the mom (and dad)

I believe the conclusion is things like birth weight and mom's bmi aren't primary drivers of autism.

What led to increased diagnosis of autism was evaluating more kids who had autism.

it's not that a CS causes ASD but that children who have ASD are more likely to need a CS, and the availability of a CS allows more children with ASD to survive, and therefore an increase of CS births correlates with an increase of ASD

> I have seen studies that correlate c-section deliveries with a somehat significant increased chance of autism, so that would track.

I think older age of mothers are correlated with both?

As I mentioned in another reply, heavy birth weight is another stat somewhat significantly correlated with ASD diagnosis that could correlate with c-sections. Interestingly high birth weight seems to be more common in mothers in their 20s.

High birth weight is also correlated with gestational diabetes. There could be some metabolic or hormonal intersection with autism here.

It's a disability if it impacts one or more major life function. Otherwise it's just an answer to a question you might not have even known you wanted to ask.

I'm sure I would've been diagnosed autistic as a kid instead of just difficult. Not sure it would've changed anything. I still would've been very strong willed and confused about why people around me say one thing but do a different thing. I think what would've been different is maybe other people's reaction to me?

> Not sure it would've changed anything.

I think the biggest benefit to diagnosis is both the parent and the child are able to draw on resources for those disabilities - learn about coping mechanisms, get advice from other autistic people, etc.

> confused about why people around me say one thing but do a different thing.

I think it importantly helps shift this confusion from the framing of "Is something wrong with me?" which a lot of young autistic people feel

Well sure, "disability" doesn't mean "different", it means "less able to do certain things".

a disability or illness implies the need to be cured. but for high functioning autistic people it is not clear whether they are actually having a disability or an illness that needs curing. if something doesn't need curing then it's not an illness, nor a disability. so either we don't diagnose people who don't need curing but do need an explanation for their differences as autistic, or we accept that at least some high functioning autistic people are not disabled or ill.

i mentioned before the book "Speed of Dark" by Elisabeth Moon which explores this topic.

My oldest and youngest are autistic and are 10y apart. Only the younger is diagnosed.

The difference is how difficult it was to obtain an autism diagnosis (here,then).

For the former, it was difficult to impossible to find someone who was ¹qualified and ²willing to consider autism.

For the latter, qualified specialists were readily available and the diagnosis was seamless.

I'm short on time and couldn't read the whole article, but apparently metabolic health is a huge factor that doesn't seem to be pointed at here. Obese parents, both mum and dad, multiply the likelihood of child autism by something like 4x. It could be that the obesity epidemic is the cause of the rising autism rates. Same goes for other metabolic health impacting factors such as diabetes, hypertension, and the likes.

The paper says there is no epidemic and never was. The only increase is in diagnosis. That is due to a number of causes like changing the criteria for diagnosis, adding incentives to be diagnosed, and several other things. The two strongest arguments presented were that autism isn't rarer in adults, and some studies that involved testing with tests that haven't changed over the period didn't see a change in actual scores even though diagnosis increased. My personal thoughts are that autoimmune conditions that have similar effects to some aspects of autism are demonstrared to increasing, and when that happens in young people it gets diagnosed as asd because that has a name and gets extra services vs having some poorly understood autoimmune thing.

> Obese parents, both mum and dad, multiply the likelihood of child autism by something like 4x. It could be that the obesity epidemic is the cause of the rising autism rates.

Even assuming the first sentence is correct going from 0% prevalence to 100% prevalence of something with a 4x risk increase would explain only a very small part of the increase in the various proxies by which the prevalence is estimated, whereas (as the article argues) change in diagnostic criteria and reporting practices can easily explain all of it. So, sure, to the extent there is any real increase in prevalence (which is not at all clear), factors like parental obesity, parental age, and other things that have some indication of being either risk factors or proxies for unidentified risk factors may either play a role or be indicative of things that do, but we can be fairly certain what the main driving factor in the numbers is, and it is sufficient to explain the observations, and invoking anything else is a violation of the principal of parsimony.

I'm talking about it in another thread too, but large birth weight is apparently a pretty significanly correlated risk factor for developing ASD. Studies show that obese mothers are more likely to give birth to higher weight children.

Fortunately, there are independent multibillion dollar industries who would prefer to solve it with semaglutide, tirzepatide, and retratutide.

Of course, the article makes the case that there's no epidemic so none of this is really important. We don't have to go "oh woe is me oh woe is me" constantly.

How does obesity correlate with IQ? As the article points out:

> So much spending on care for autistic people is wasteful. Someone with a mild case of Asperger’s does not need to hit a mandated spending cap for their condition, and someone with mental retardation who convinced a clinician to give them a more favorable diagnosis should not be receiving treatment intended for autistics and found to be useless for the merely mentally retarded.

More importantly, even if the article didn’t specifically address your concerns about metabolic health, it certainly gave a plethora of reasons for why the “rising autism rates” are not rising in truth.

> So remember this:

> There is not, and has never been, any credible evidence for a “real” epidemic of autism or for any of its proposed environmental causes. Answering the question of if there is a “real” autism epidemic has provided a complete answer to the question of why there might be.

Long, thorough, and worth reading to the end.

There have been various studies on the potential connection between autism and the prevalence of a parent (most often the father) of working in STEM. Heightened incidences in areas of Silicon Valley for example where both parents work in STEM as well have been observed as hotspots.

This had also been observed by clinical psychologists working with autistic children as a curious anomaly (a friend has a PhD in this topic and has worked for 30 years with families who have an autistic child) that when first meeting the parents it was often observed that one of the parents (often the father) displayed ASD tendencies and was often undiagnosed.

One could therefore argue that the “resurgence of the nerd” has been partially a trigger for an increase in autism cases, but more than likely the higher incidence of diagnosis is the stronger factor.

Of course men are more likely to work in STEM.

As with all complex psychological divergences, it is highly likely that autism has a number of factors that can trigger it, and as we see in all highly specialized science topics, that in which you specialize is where you seek the answer. When all you have is a hammer…

Dickerson, A. S., Rahbar, M. H., Han, I., Bakian, A. V., Bilder, D. A., Harrington, R. A., … & Kirby, R. S. (2014). Autism spectrum disorder prevalence and association with parental occupation in the Texas Autism Surveillance Project. ScienceDaily.

Baron-Cohen, S., Wheelwright, S., Stott, C., Bolton, P., & Goodyer, I. (1997). Is there a link between engineering and autism? Autism, 1(2), 153-163.

Baron-Cohen, S., Scott, F. J., Allison, C., Williams, J., Bolton, P., Matthews, F. E., & Brayne, C. (2012). Diagnosed autism is more common in an IT-rich region. Cambridge University Research News.

Baron-Cohen, S., Wheelwright, S., Skinner, R., Martin, J., & Clubley, E. (2001). The Autism-Spectrum Quotient (AQ): Evidence from Asperger Syndrome/high-functioning autism, males and females, scientists and mathematicians. Journal of Autism and Developmental Disorders, 31(1), 5-17.

Dickerson, A. S., Rahbar, M. H., & Pearson, D. A. (2014). Parental occupation and risk of autism spectrum disorder in offspring: A population-based study. Research in Autism Spectrum Disorders, 8(8), 974-985.

Feldman, M., & Belsky, J. (2023). Parental STEM skills and risk of autism spectrum disorders in children. Journal of Political Economy, 131(4).

Lazic, S. E., & McLean, R. J. (2023). STEM-skilled parents and autism spectrum disorder in offspring: A case-control study. ResearchGate preprint.

Has the use of SSRIs or ADHD drugs while pregnant/breastfeeding been studied?

That sort of info that is routinely collected, when studies involve prenatal/postnatal data.

I had older relatives who were obviously or probably autistic but were undiagnosed - because who had even heard of autism then. AHD meds and SSRI weren't yet a thing - but these folks mostly predated even Tricyclic ADs.

The linked article conclusion is that there is no real increase in the real rate of autism, only in the measurements.

RFK Jr.: "I'm going to feed all the data we have into this analysis machine which will tell us at last, what the cause of the autism epidemic is."

[He pushes the button on a photocopier into which a piece of paper reading "IT'S THE VACCINES" has been placed]