We can prevent autism.

Our first comprehensive review of the connection between acetaminophen and autism was first submitted for publication in June of 2016, and was eventually published in early 2017 here: https://pubmed.ncbi.nlm.nih.gov/28415925/ That paper contains a very detailed description of the factors that interact with acetaminophen, leading to neurodevelopmental injury. That paper is still (as of late 2024) the most detailed treatment of factors causing susceptibility to acetaminophen-induced neurodevelopmental injury. This first review paper also introduced at least one new line of evidence, but it contains only 14 total lines of evidence. Not only do we now have many more lines of evidence, but the 14 lines of evidence presented in this paper are now much stronger. Therefore, this paper is not current in most respects.

 

In this first review, we conclude that “The bottom line is that hundreds of studies describing the epidemiology of autism and the numerous and varied risk factors for autism have a straightforward explanation: autism could be an acetaminophen-induced brain injury facilitated by oxidative stress and inflammation in newborns and young children. This is certainly an attractive view from an intellectual perspective, as it satisfies Occam’s razor.”

 

Published in 2022, five years after the first review, the second review takes an important step beyond the “could be” assertion made in the first review. In the second review, we conclude “without reasonable doubt” that exposure of susceptible children to acetaminophen is responsible for “many if not most” cases of autism spectrum disorder. That paper was published here https://pubmed.ncbi.nlm.nih.gov/35822581/. The paper contains a detailed analysis of laboratory animal studies, concluding that acetaminophen could never be used in babies and children, even on an experimental basis, if it had to pass current drug testing standards used by the FDA. However, that paper describes only 17 lines of evidence, and has been superseded by other papers described below which describe more lines of evidence.  

 

The third review paper in the series was submitted for publication in October of 2022, but was not published until early in 2024. Sometimes publication of scientific papers can take considerable amounts of time.  This paper described 20 lines of evidence demonstrating that exposure of susceptible babies and children causes many if not most cases of autism, and was published here: https://pubmed.ncbi.nlm.nih.gov/37321575/. It contains a detailed analysis of lines of evidence originating from the 2008 Schultz study parsing out the contribution of vaccines versus acetaminophen to autism. This third review paper is the only one that provides a detailed analysis of that evidence from Schultz. However, again, other papers have been published with additional evidence. In this case, the fourth review paper (see below), describing 22 lines of evidence, was published just a few days before this paper, meaning that this third review paper was outdated in some regards even before it was published. This situation is not unique in the field of science. Some papers get published faster than others, in this case due to differences in the time required for different scientific journals to publish the manuscript.

 

The fourth review paper in the series describes 22 lines of evidence demonstrating that exposure of children to acetaminophen is responsible for many if not most cases of autism https://pubmed.ncbi.nlm.nih.gov/38255358/. This fourth review is the first one in which we conclude that available evidence is consistent with the view that acetaminophen exposure in susceptible babies and children is responsible for “the vast majority” of all cases of autism. The paper was submitted for publication in November of 2023, and was published in December of the same year, shortly before the third review paper (described above) was published. Published in the journal “Children”, this fourth review paper is by far the most user-friendly paper on the topic we have published. It contains recommendations for medical practice, but of course does not contain medical advice for individuals. Only a medical doctor can provide medical advice for individuals.

 

Our fifth review paper on the topic described two new lines of evidence demonstrating the connection between acetaminophen and autism, bringing the total number of lines of evidence up to 24  https://pubmed.ncbi.nlm.nih.gov/39202661/. This paper contains a very detailed explanation of one new and important line of evidence: the similarities between autism spectrum disorder and fetal alcohol spectrum disorder. It also contains an analysis of historical evaluations of the prevalence of autism, which are important for two more lines of evidence related to temporal associations between acetaminophen use and autism. Finally, the paper contains a detailed proof of the fact that current studies related to two other lines of evidence have been grossly misguided. These two lines of evidence involve associations between autism and acetaminophen use during

pregnancy (one line of evidence) and early childhood (another line of evidence) based on “observational” studies of healthcare databases. To summarize this paper, it contains a highly detailed scientific analysis of several lines of evidence, and it is the most current paper in the series, being based on 24 lines of evidence. However,

this fifth paper does not contain a complete summary of all lines of evidence, and parts of it are not written to be digestible for the non-expert in statistical methods.  Thus, the fourth review paper described above, published in Children, is still recommended as a general review for most people.

 

As the list matures, we continue to make old lines of evidence tighter and better, adding more information backing up some lines of evidence. The current 33 lines of evidence are compiled into our peer reviewed papers and in our preprints. A preprint is a paper that has not been peer reviewed, although the evidence presented in our preprints is published in the peer reviewed literature. So, although the lists of evidence in our preprints haven’t been peer reviewed, the evidence in those lists is peer reviewed.  

Some of the most recent evidence we have is also some of the most shocking and exciting, although it’s exciting in a rather horrific way. Basically, new evidence is showing tremendous increases in the prevalence of autism among groups with low socioeconomic status, and that evidence is pointing to a factor that makes acetaminophen even more toxic. That evidence is described here (https://www.preprints.org/manuscript/202604.0581) and here (https://www.preprints.org/manuscript/202609.0461).

This manuscript describes key reasons why many investigators have missed the connection between acetaminophen and autism spectrum disorder during the past two decades. ( )   

This manuscript describes work at the University of North Carolina in laboratory animals showing that acetaminophen can have very wide-ranging and even seemingly contradictory effects on brain development in laboratory animals. https://papers.ssrn.com/sol3/papers.cfm?abstract_id=5223387

The bottom line is that it’s impossible to induce a neurodevelopmental injury in more than 2% of the population without leaving a trail of evidence. The evidence we have simply doesn’t fit into a single paper, and is spread out in reviews published over a period of almost a decade. With that in mind, please be patient as you sort through the evidence, and let us know if you have questions.