Topic 1: What does NOT cause autism?

In the past, some in the medical profession, as well as high-profile celebrities and others, have raised the ideas that autism is caused by bad parenting or childhood vaccines. Although it has been proven that parenting styles and vaccines do not cause autism, some people may still believe these fallacies.

According to 100 Day Kit for Newly Diagnosed Families of School Age Children, the idea that autism was caused by bad parenting was first put forth by the psychologist Dr. Leo Kanner. Dr. Kanner was the first to identify autism as its own condition in 1943, but he also believed that autism was caused by unloving mothers.

This idea was further promoted by Bruno Bettelheim, a well-known professor of child development, in his book The Empty Fortress: Infantile Autism and the Birth of the Self. It wasn't until the 1960s and 70s that Dr. Bernard Rimland, author of Infantile Autism, the father of a son with autism and the founder of the Autism Society of America and the Autism Research Institute, demonstrated that autism is caused by biological factors and is not the result of cold parents. Nevertheless, there were generations of parents who felt that it was their fault that their children had autism, despite later evidence that this is untrue.

The idea that vaccines cause autism is more recent. In 1998 the British medical journal, The Lancet, published a study by Andrew Wakefield and his colleagues that alleged a link between the measles-mumps-rubella (MMR) vaccine and autism. What the public did not know at the time was that this study involved only 12 children and contained falsified data. It was also found that Wakefield had a financial interest in showing the impact of vaccines on ASD.

Another idea at the time was that a mercury-based ingredient, Thimerosal, in vaccines caused autism. Extensive, sensational media coverage followed, which caused many people to believe in the paper's thesis. This resulted in the lack of immunization for many children and exposure to children with those diseases to many others, particularly by infants.

Meanwhile, the medical community conducted many extensive follow-up studies, none of which found a link between the MMR vaccine and autism. In 2004, ten of the thirteen authors of the Wakefield paper retracted their interpretation of the evidence. In 2010, The Lancet formally retracted the Wakefield paper. Wakefield also lost his medical license because of the dishonest and irresponsible way he conducted his MMR-autism study. Furthermore, beginning in 2001 the ingredient Thimerosal, which contains mercury, was removed from all childhood vaccines in the United States as a precaution, even though there was no evidence Thimerosal caused neurological harm to children. You can find a detailed timeline and information about many of these studies on NOVA's webpage, The Autism-Vaccine Myth.

The Autism-Vaccine Myth page argues that people continue to believe in the link between autism and vaccines because of timing. Many childhood vaccines are given on a schedule that coincides with the times when parents begin to notice the signs of autism in their children. However, multiple scientific studies have proven that there is no link between vaccines and autism. You can find the full citations to some studies in the References section, links in the following paragraph, and more studies' citations on the CDC's website.

In the 21st century, several noteworthy research studies illuminated some of these false connections with autism.

• A 2004 review conducted by the Institute of Medicine, Immunization Safety Review: Vaccines and Autism, also found no link between autism and Thimerosal and autism and the MMR vaccine.

• A 2008 study of children in California, Continuing increases in autism reported to California's developmental services system: mercury in retrograde, also found no support for the idea that autism is caused by Thimerosal.

• A 2013 study funded by the CDC, and published in The Journal of Pediatrics, Increasing Exposure to Antibody-Stimulating Proteins and Polysaccharides in Vaccines Is Not Associated with Risk of Autism, found no evidence linking vaccines children received in their first two years of life and a higher risk of ASD.

• A 2014 study, Vaccines are not associated with autism: An evidence-based meta-analysis of case-control and cohort studies, found no links between vaccinations and ASD or autism, or links between autism the MMR vaccine, or links between ASD and the vaccine ingredients Thimerosal and mercury.

You can find more links to relevant research studies on this topic on the CDC's website.

Studies have also been done to debunk the myth that the Amish don't have as many cases of autism because they do not vaccinate their children. Although the Amish do have lower vaccination rates than the general population, a study published in 2011 in Pediatrics surveyed 1,000 Amish parents in Holmes County, Ohio and found that only 14% of survey respondents did not vaccinate any of their children, while 85% of respondents had at least one of their children receive at least one vaccination. Meanwhile, a paper presented at the 2010 meeting of the International Society for Autism Research, presented the results of a survey that screened 1899 children for ASD in Ohio and Indiana. The paper found a prevalence rate of 1 in 271 children diagnosed with ASD. Again, while this is lower than the prevalence rate of the general population, it also shows that the Amish are not an excluded population of those affected by ASD.

Finally, the U.S. "vaccines court," a division of the U.S. Court of Federal Claims, has also repeatedly ruled that there is no connection between vaccines and autism. The court ruled in 2009 that a combination of the MMR vaccine and Thimerosal does not cause autism, and additionally ruled in 2010 that Thimerosal by itself does not cause autism. The "vaccines court" determines if children have been harmed by vaccines. If the court determines that the vaccine did cause harm, it awards compensation.

Activity:

Read the following statements about the causes of autism below and decide if each one is Fact or Fiction.

References

Autism Speaks Family Services (2014). 100 Day Kit for Newly Diagnosed Families of School Age Children. Retrieved from https://www.autismspeaks.org/family-services/tool-kits/100-day-kit-school-age.

Centers for Disease Control and Prevention. (2015, November 23). Vaccines do not cause autism. Retrieved from https://www.cdc.gov/vaccinesafety/concerns/autism.html.

DeStefano, F., Price, C. S., and Weintraub, E. S. (2013). Increasing exposure to antibody-stimulating proteins and polysaccharides in vaccines is not associated with the risk of autism. The Journal of Pediatrics, 163(2), 561-567. http://dx.doi.org/10.1016/j.jpeds.2013.02.001

Dominus, S. (2011, April 20). The crash and burn of an autism guru. The New York Times Magazine. Retrieved from http://www.nytimes.com/2011/04/24/magazine/mag-24Autism-t.html.

Immunization Safety Review Committee, Board on Health Promotion and Disease Prevention (2004). Immunization safety review: Vaccines and autism. Washington, D.C.: The National Academies Press.

International Society for Autism Research (2010). International Meeting for Autism Research: Prevalence rates of ausim spectrum disorders among the old order Amish. Retrieved from http://archive.is/wrvdA#selection-15.0-15.114. 

Lai, M., Lombardo, M. V., & Baron-Cohen, S. (2014). Autism. The Lancet, 383(9920), 896-910. doi:10.1016/S0140-6736(13)61539-1.

Maugh, T. H. II & Zajac, A. (2010, March 13). "Vaccines court"rejects mercury-autism link in 3 test cases. Los Angeles Times. Retrieved from http://articles.latimes.com/2010/mar/13/science/la-sci-autism13-2010mar13.

Taylor, L. E., Swerdfeger, A. L., and Eslick, G. D. (2014). Vaccines are not associated with autism: An evidence-based meta-analysis of case-control and cohort studies. Vaccine, 32(29), 3623-3629. https://doi.org/10.1016/j.vaccine.2014.04.085

Wenger, O. K., McManus, M. D., Bower, J. R., Langkamp, D. L. (2011). Underimmunization in Ohio's Amish: Parental fears are a greater obstacle than access to care. Pediatrics 128(1). doi: 10.1542/peds.2009-2599.