I have been involved in caring for children with autism since I was in medical training in the 1980s. I am compelled at this time to take a long view of autism as we look at the current swirl of ideas and suggestions about causes and treatments.

My Pediatric textbook from the 70s suggested the prevalence of autism was 2 in 10,000 children. A condition that most of us in training wondered if we would ever even see in our practices.

A lot has changed; certainly, there seems to be a rise in the frequency of autism, even as we also recognize there has been a reclassification of diagnosis. The latest numbers by the Centers for Disease Control and Prevention, show one in 31 children aged 8 years old were diagnosed with autism spectrum disorder in 2022, up from one in 36 two years earlier and one in 150 in 2000. Now, pediatricians with busy practices see children with autism every day.

When Hypotheses become Hot Topics

When I really focused, in earnest, to care for children with autism as a concentration of my practice, it was about 1997-98.

Two hot topics became burning ideas in 1998; Andrew Wakefield had proposed a hypothesis that vaccination for the measles virus might be triggering a GI inflammation and setting off autism because of intestinal permeability changes. He was a dynamic speaker and built a plausible story around why this hypothesis could explain the rising tide of cases.

In the same year, Karoly Horvath had described a limited number of children with autism that he had tested by endoscopy. These children were reported by their families to have shown improvements following the endoscopy, and he speculated that Secretin, a GI hormone he had administered during the testing, might have central nervous system benefits. Like Wakefield, he tried to explain how this might fit as an explanation with a plausible mechanism. His experience using Secretin, along with the families who saw benefits, was featured on ABC-TV’s “Dateline” and the autism community was energized.

The absolute benefit of these events was to prompt families to seek advice from providers, to consider the possibility of “non-neurological” factors contributing to autism, and to really push the idea that comorbidity (associated conditions) seen in individuals with autism was important to address. The day after the “Dateline” show aired, my already busy practice exploded with requests for appointments. 

Research Validates or Disproves

Following the advancement of these hypotheses, the hard work began. Research into whether these hypotheses could have merit was performed, and several studies showed no value from the administration of Secretin as a therapy for autism. As for the measles vaccine hypothesis, I was fortunate to work with a long list of committed researchers at Massachusetts General Hospital and Columbia University.  Mady Hornig was the first author of our paper, which could not demonstrate the measles virus in the gut of the patients undergoing colonoscopy. We included 3 different pathologists (including the pathologist who identified the finding in Wakefield’s paper) to evaluate the biopsies using the best technology available to attempt to reproduce the findings described. None of us was out to prove these hypotheses wrong. We were out to reproduce and confirm or refute the findings. Our research could not provide evidence to support the original hypothesis. That is how science advances our understanding of ideas.

As part of our research paper, Lack of Association between Measles Virus Vaccine and Autism with Enteropathy: A Case-Control Study PLOS-One, 2008; September, Volume 3, Issue 9, e3140, 1-8 (see item 22 in the Research Publications listing on www.DrTimBuie.com to read the abstract), we also did a much deeper investigation of the timing of the onset of autism symptoms.  We found that the children in our study had findings consistent with the presence of autism even before the child received the vaccination for measles. Often, early on, the features are not clear enough for families to recognize, and they will link the onset of autism to a temporal event such as illness or vaccination. Following these limited studies looking at GI biopsies, more support against the measles vaccine causing autism came from a number of large population-based studies comparing the prevalence of autism in vaccinated children and unvaccinated children. One study from Denmark, A Population-Based Study of Measles, Mumps, and Rubella Vaccination and Autism, N Engl J Med 2002;347:1477-1482 DOI:10.1056/NEJMoa021134 VOL. 347 NO. 19 demonstrated no difference in autism in those vaccinated with the MMR vaccine compared to unvaccinated children.

Despite these thorough studies, families remain concerned, to this day, that something about vaccines is posing a risk. Recent debate about thiomersol, a preservative in some vaccines, and identified as a possible factor in autism causation, has bubbled back to our consciousness after large population-based studies demonstrated no difference in autism prevalence when it was or was not present in childhood vaccines.

Most physicians caring for individuals with autism continue to believe that autism is a cluster of symptoms and behaviors that are likely caused by genetic factors, with more than 100 described genetic associations. If I am a parent of an individual with autism, to be told the genetic testing was normal or inconclusive, I am left searching for answers. Families continue to be frustrated by our inability to explain why their child is affected. Parents, and I believe physicians as well, need to continue searching and considering other factors that could be contributing to the causation of autism and identifying effective treatments that have not been previously tried.

Current Theories Require Scientific Study

Now, let’s look at what is going on currently. I am grateful that our current administration and our president have put autism front and center for discussion. In a press conference held in September 2025 we heard about two hypotheses: First, that prenatal exposure to acetaminophen might be a contributory factor to altered brain development, causing autism. Second,  a potential treatment, Leucovorin, should be made more easily available to treat individuals with autism (This treatment hypothesis was presented earlier in 2025 on “60 Minutes”). If authorized for autism therapy based on current data, we will be looking at a lot of future treatments that have not had rigorous review to evaluate the benefit, side effects and potential risks of these treatments. The practice of responsible medicine is better than this.  Science and research are better than this.

There has been a firestorm of discussion since these ideas were presented. Most, if not all, medical societies forwarded the strong data already in the literature supporting against identifying acetaminophen as a causative agent.

Even the researcher who has written about Leucovorin suggested that using it as a treatment is still preliminary and that research should continue to understand the medication better and who might benefit from its use.

My prayer is that attention to autism continues. I am tremendously hopeful that a commitment to improved research hypotheses is better supported. I caution our politicians and our medical community to clearly communicate when a theory of causation or a treatment idea comes forward, we should explain that these are preliminary and require more scientific review and analysis.

Remembering the treatments that have come and gone (and come back again when a new generation of families is digging through the archives to find ways to help their children) is so important. We can learn from history. We can certainly learn from science.

I have to say I have not learned much yet from press conferences or news shows, or influencers on social media, about treatments for my patients. I am hopeful that families and providers can help our political leaders understand that there is a proper pathway to doing scientific research. We should be advocating for this. If finding out what causes autism and figuring out how we can improve the lives of individuals with autism is really a priority, supporting good research is truly welcome.