Autism Studies

Evidence: Published Studies

It is confusing for parents to read many of the comments in the mainstream media about autism and other neurological disorders (“NDs”). Typically, these NDs are described as having “no known cause and no known cure” and any link between vaccines and NDs is typically said to have been “disproven”.

In fact, the evidence supporting the position that NDs are environmental illnesses with vaccines as a primary trigger is well documented, published in peer-reviewed journals, and growing every day.

Please note that most of the published science deals with autism, which we feel is equally relevant for a child with ADD/ADHD. What can parents learn from the existing science today? Generation Rescue believes the following has been proven to be true:


The prevalence of neurological disorders amongst children is growing, which means the environment must be playing a role (because genetic conditions can only grow at the rate of population growth).

We cite four published studies that support this position:

Report to the Legislature on the Principle Findings from The Epidemiology of Autism in California: A Comprehensive Pilot Study
MIND Institute, UC Davis, Oct 2002.
Robert Byrd

Using data from California, the state perceived to maintain the best data on autism, this report demonstrates clearly that the rise in autism is not due to improved diagnosis and expanded diagnostic criteria, but is rather a REAL rise for which some external factor must be playing a role. Excerpt:

“There is no evidence that a loosening in the diagnostic criteria has contributed to increased number of autism clients…we conclude that some, if not all, of the observed increase represents a true increase in cases of autism in California…a purely genetic basis for autism does not fully explain the increasing autism prevalence. Other theories that attempt to better explain the observed increase in autism cases include environmental exposures to substances such as mercury; viral exposures; autoimmune disorders; and childhood vaccinations.”

National Autism Prevalence Trends From United States Special Education Data.
Pediatrics, March 2005.
Craig J. Newschaffer, PhD [Johns Hopkins University].

This study shows that the rise in the incidence of autism is real and that the greatest increase took place between 1987 and 1992, which matches the timing of the near-tripling of vaccines given to our children and the tripling of mercury within those vaccines.

The Changing Prevalence of Autism In California
Journal of Autism and Developmental Disorders, April 2003
Mark Blaxill, MBA

This study helps to refute the supposition made by some researchers that autism’s epidemic may only be due to “diagnostic substitution”. Excerpt:

“They have suggested that ‘diagnostic substitution’ accounts for an apparent increase in the incidence of autism in California that is not real. This hypothesized substitution is not supported by proper and detailed analyses of the California data.”

What’s Going On? The Question of Time Trends in Autism.
Public Health Reports, Nov-Dec 2004.
Mark F. Blaxill, MBA.

This detailed analysis of reported rates of autism in the United States and United Kingdom serves to further refute the assertion made by some that the “epidemic” of autism is nothing more than better diagnosis.


When environmental toxicity in children with neurological disorders is measured, it is meaningfully higher than neurotypical (normal) children.

We cite five published studies that support this position:

Porphyrinuria in Childhood Autistic Disorder: Implications for Environmental Toxicity
Toxicology and Applied Pharmacology, 2006.
Robert Nataf, Corinne Skorupka, Lorene Amet

This new study from France utilizes a new and sophisticated measurement for environmental toxicity by assessing porphyrin levels in autistic children. It provides clear and unequivocal evidence that children with autism spectrum disorders are more toxic than their neurotypical peers. Excerpt:

“Coproporphyrin levels were elevated in children with autistic disorder relative to control groups…the elevation was significant. These data implicate environmental toxicity in childhood autistic disorder.”

A Case Control Study of Mercury Burden in Children with Autism Spectrum Disorder.
Journal of American Physicians and Surgeon, 2003.
James Adams, PhD [Arizona State University].

This recent study shows, through active chelation with DMSA, that autistic children excrete significantly higher levels of mercury than their neurotypical peers, leading to the conclusion that autistic children bear a much higher load of mercury in their bodies and that chelation may be an effective treatment for removing the mercury. Excerpt:

“The data from this study, along with emerging epidemiological data showing a link between increasing mercury doses from childhood vaccines and childhood neurodevelopmental disorders, increases the likelihood that mercury is one of the main factors leading to the large increase in the rate of autism and other neurodevelopmental disorders. It is hoped that removing thimerosal from all childhood vaccines will contribute to a decline in the numbers of new cases of autistic spectrum disorders.”

A Case Series of Children with Apparent Mercury Toxic Encephalopathies Manifesting with Clinical Symptoms of Regressive Autistic Disorder
Journal of Toxicology and Environmental Health, 2007
David A. Geier, Mark R. Geier

This study reviewed the case histories and medical profiles of nine autistic children and concluded that eight of the nine children were mercury toxic and this toxicity manifested itself in a manner consistent with Autism Spectrum Disorders. Excerpt:

“…these previously normally developing children suffered mercury toxic encephalopathies that manifested with clinical symptoms consistent with regressive ASDs. Evidence for mercury intoxication should be considered in the differential diagnosis as contributing to some regressive ASDs.”

Attention-deficit hyperactivity disorder and blood mercury level: a case-control study in chinese children
Neuropediatrics, August 2006
P.R. Kong [Department of Pediatrics and Adolescent Medicine, The University of Hong Kong].

This study demonstrates that blood mercury levels are higher for children with ADHD. Excerpt:

“There was significant difference in blood mercury levels between cases and controls, which persists after adjustment for age, gender and parental occupational status. The geometric mean blood mercury level was also significantly higher in children with inattentive and combined subtypes of ADHD. CONCLUSION: High blood mercury level was associated with ADHD. Whether the relationship is causal requires further studies.”

Reduced Levels of Mercury in First Baby Haircuts of Autistic Children
International Journal of Toxicology
Dr. Amy S. Holmes, Mark F. Blaxill, Boyd E. Haley, Ph.D.
March 14, 2003

This recent study demonstrates that the levels of mercury in the birth hair of autistic children were significantly lower than their control peers. While this may at first appear contradictory, it highlights one of the critical insights to understanding mercury poisoning and autistic children: many autistic children are non-excretors of mercury. This means their capacity to excrete mercury is significantly lower than their neurotypical peers and contributes to their condition.