Q&A of the Day – If Not Acetaminophen What’s Behind the Rise in Autism?
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Today’s entry: Hi Brian. Thanks for all your hard work and dedication. I understand that there is almost a fivefold increase in autism spectrum disorder since the year 2000. What increase has there been in more severe levels (levels 2 or 3, requiring substantial or very substantial support)? And given the potential for acetaminophen to be a cause (or partial cause) for this increase, I would expect a significant increase in Tylenol use among pregnant women during this time period. However, all the data I have found shows relatively negligible changes in either direction and probably stable use over this time. What data is RFK using to show a significant increase in Tylenol use?
Bottom Line: As the debate over the recent HHS recommendations against the use of acetaminophen continues, you’ve asked great questions. I’ll start by answering your question about the increase in advanced autism cases has been overtime. Using the CDC's Autism and Developmental Disabilities Monitoring database, here’s what we know about advanced cases (level 2 & 3).
This is based on ASD (advanced) cases per 1,000 children:
- 2000: 3.4 cases
- 2016: 6.1 cases
- 2018: 8.1 cases
- 2022: 12.8 cases
What this shows is a 377% increase in advanced cases of diagnosed autism over the previous 22 years. The increase tracks almost exactly with the overall increase in diagnosed autism cases which have grown from 1 in 150 children in 2000 to 1 in 31 cases most recently. Advanced cases have risen from 1 in 294 children in 2000 to 1 in 78 children most recently. That comparison is also instructive in terms of perhaps dispelling thoughts that most of the increase is due to simply more awareness by the medical establishment. Advanced autism was certainly well accounted for by the CDC dating back to 2000 and at all points in between.
In terms of the research that was provided by RFK Jr. And the Department of Health and Human Services on Monday, leading to the department’s recommendation against the use of acetaminophen, there’s a detailed analysis of this with a lengthy fact sheet to review. By my count there were at least 20 studies reviewed as part of the analysis in making the recommendation. As for your final question regarding what may be a disconnect between a seemingly steady level of use of acetaminophen by pregnant women during the rapid increase in autism cases, that’s instructive all the same. I’ll explain.
While acetaminophen usage hasn’t spiked over the decades, usage of just about everything else has. There has been a significant increase in the use of medications by pregnant women since 2000, driven by factors such as rising maternal age, higher prevalence of chronic conditions (diabetes, obesity, mental health disorders), and expanded indications for certain drugs like antidepressants and opioids. The trend is evident in both prescription and overall medication use, including polypharmacy (multiple medications), and is supported by studies across the US, Canada, Europe, and Denmark.
Specifically, in drilling down into U.S. data, prior to 2000, only around a third of pregnant women were on at least one other drug during their pregnancy. Most recently that number has jumped to 90%. What’s more is that often there are multiple medications that are in use. This is an extremely important context that was touched on by the administration in making the recommendation. It may be the case that using recommended levels of acetaminophen on its own during pregnancy hasn’t contributed to the spike in autism cases, but perhaps it’s interaction with the rise in other medications that are now being taken by pregnant mothers during pregnancy. This is an unknown.
When breaking this down here’s what we know:
- The rise in advanced autism cases is consistent with the overall increase in diagnosed cases
- Acetaminophen usage is common among pregnant mothers and usage levels appear to be relatively consistent
- There’s been a significant increase in pregnant mothers using other drugs in addition to acetaminophen
With that information in hand reasonable deductions may be made. It may well be the case that if women weren’t waiting as long to have children – which has been a growing trend, and were generally in better health heading into pregnancy, the spike in autism perhaps wouldn’t be what we’ve seen. It’s logical enough. But given that it is the case, and that often medications in use for would-be mothers that didn’t used to be, it could also be the case that adding acetaminophen in the mix during pregnancy is one drug too many. That’s also logical.