Dr. Anjum Usman and Dr. Daniel Rossignol are being sued by James Coman for providing what Coman claims is fraudulent treatment for his son's autism (see http://abcnews.go.com/Health/AutismNews/doctors-sued-autism-chelation-th... for ABC's version of the story). These two doctors are part of the Defeat Autism Now! ® (or DAN!) network of physicians. DAN! Director Jane Johnson promotes DAN's commitment to providing seminars to help families of children with ASDs recover their children.

She states:
There is no other conference with an agenda devoted to teaching how GI disorders, detoxification and other metabolic issues, and nutrition impact a child's sense of self, behavior, attention, speech, and general health. Our scientific principles and protocols apply to affected children of all ages and varying conditions. Often, an underlying metabolic problem is found to be the cause of symptoms associated with autism, so that when a biochemical "glitch" is identified by lab test and then addressed, the child's "quirk" diminishes or goes away.

I'll tackle the detoxification notion below. As I mentioned in a previous post, GI problems are no more likely to occur in individuals with ASDs (http://www.psychologytoday.com/blog/radical-behaviorist/201001/are-child...). It is also unlikely that diets will treat ASDs (http://www.psychologytoday.com/blog/radical-behaviorist/201001/is-elimin...). Furthermore, the recent expert consensus review of gastrointestinal disorders in persons with ASDs states that there is no strong evidence to suggest that there is any increased prevalence of intestinal inflammation, increased intestinal permeability, immunologic abnormalities, or food allergies in ASDs (Buie et al., 2010). Granted, there is certainly cause for further investigation of these matters but the evidence to date does not support these as primary problems for individuals with ASDs. As an aside, it is important to note that it might be more difficult to nail down such problems in persons with limited communicative skills. However, in my clinical experience, when there have been food allergies or GI problems present for children with limited communication skills there have also been overt physical symptoms of them that have assisted us in identifying these problems. That said, when these physiological problems have been treated (and yes, through dietary restrictions for children with true food allergies) their developmental delays did not disappear as Jane Johnson implies sometimes happens. Then again we are not DAN! certified practitioners.

I've largely covered this ground in the context of debunking the Andrew Wakefield inspired myth that the MMR vaccine causes autism. In this discussion it is now time to take on the thimerosal in vaccines causes autism myth. There has been no sound scientific evidence establishing a link between thimerosal-containing vaccines and autism. Thimerosal is a preservative that has been used in some vaccines since the 1930s. Thimerosal consists of 49% ethylmercury and some have suggested, partly because of the known effects of methylmercury (an commonly encountered environmental contaminant) as a toxic substance, that thimerosal delivered in vaccines causes autism to develop in some children. Much is known about the effects of the more dangerous methylmercury. In the developing child, massive systemic damage can occur through excessive methylmercury exposure. The Food and Drug Administration (EPA, retrieved June 2005) has advised pregnant women, nursing mothers, and young children limit their intake of certain types of fish, like tuna, that tend to contain high levels of methylmercury in order to prevent excessive methylmercury consumption.

Much less is known about ethylmercury though some recent studies suggest it is excreted pretty quickly. The CDC reported that the cumulative exposure to ethylmercury that occurred when thimerosal was used as a preservative in vaccines was less than the FDA and World Health Organization recommended maximum safe exposure to methylmercury. However, the Environmental Protection Agency's more stringent guideline for methylmercury exposure was exceeded. Therefore, given the heightened concern over mercury exposure, the suggestion of a link between thimerosal and autism, and technology that existed for eliminating ethylmercury from vaccines, thimerosal was removed from all vaccines in the U.S. with the exception of certain flu vaccines.

But is there sound scientific evidence for thimerosal causing autism? One of the most definitive studies was conducted by Danish researchers (Hviid et al., 2003). It looked at thousands of children who received either vaccines containing thimerosal or vaccines without this preservative and found that the rates of autism were identical in the two groups. If thimerosal was causing autism, a difference should have been found. Thimerosal had been removed from the vaccines of other developed countries such as Canada and Denmark prior to it being removed from vaccines in the U.S., however, no decrease in the prevalence of autism has been detected in these countries (NYTimes, retrieved 06/25/05) and there has been no decrease in the prevalence of ASDs in the US in the nearly 10 years since thimerosal was removed from our vaccine schedule. In 2003 the American Academy of Pediatrics, an organization that called for the removal of thimerosal from vaccines in July 1999, summarized the evidence of harm from it as follows, "No scientific data link thimerosal used as a preservative in vaccines with any pediatric neurologic disorder, including autism. Despite this, the Centers for Disease Control and Prevention, American Academy of Pediatrics, National Institutes of Health, and US Public Health Service have continued to investigate this issue to put theoretic concerns about this mercury-containing compound to rest." The DAN! network, Jenny McCarthy, and anti-vaccinationists will disagree that this matter has been resolved but the scientific consensus is clear, there is no causal relation.

So how does the DAN! network detoxify? Most often they do it by chelation. Mercury detoxification, or chelation therapy, is a controversial therapy that has been suggested as a useful intervention for autism and many other conditions. One form of chelation therapy involves injecting an amino acid, EDTA, into the body. EDTA then binds with heavy metals, like mercury, and allows the body to excrete them. However, chelation is only effective for true heavy metal poisoning (though there are questions about whether it does more damage than good). Many have suggested that chelation is effective in treating arteriosclerosis but the American Heart Association (AHA, retrieved June 2005) states that there is no empirical evidence supporting this treatment. They also list several deleterious side effects possible with chelation including kidney failure, convulsions, shock, and heart and breathing difficulties. Several persons have also died while undergoing chelation. The New York Times (June 25, 2005) reported that, "One of the first to advocate treating autism with chelation and other therapies was Dr. Stephen Edelson of Atlanta...Dr. Edelson said he placed children in 160-degree saunas as part of their treatment. Some children fought to get out of the sauna and kicked out its window, an assistant said in a sworn statement. The doctor said he also used chelation and prescribed 60 to 70 supplements a day, causing some children to vomit." Dr. Edelson no longer practices medicine following a state medical board censure and lawsuits have been filed against him after several patients regressed significantly under his care.

In August 2005, the Pittsburgh Post-Gazette reported that a child with autism died during chelation therapy (Kane & Linn, 2005). Dr. Roy Kerry of Portersville, PA was administering the child's third chelation treatment. Tragically, cardiac arrest followed and the boy, who was brought to Pennsylvania from England by his mother to receive chelation therapy, died. Though the form of chelation therapy administered to the boy is not the only chelation technique, no chelation therapy procedure has been shown to provide benefit to children with autism through sound scientific study. Furthermore, chelation can result in minerals vital to neural functioning being removed from the body. It is possible that this is what caused the child's heart to stop beating.

Linn (2005) reported in a follow-up to the Post-Gazette's initial article:
(Some parents) "see chelation as a logical option because they believe there is a connection between their children's autism and the mercury preservative in childhood vaccinations. And that is what so disturbs Dr. Paul Offit, director of the Vaccine Education Center at Children's Hospital of Philadelphia. Scientific study after scientific study ha(s) found no connection, and it's unethical for any doctor to give chelation for this purpose, he said. He said doctors need to work harder to convince parents that the whole reason to use chelation is pointless. ‘I wish there was more outrage with this death. This boy was sacrificed on the altar of bad science and that was unconscionable,' he said."

Chelation is one of the keys to the lawsuit filed by James Coman against these DAN! doctors. Fortunately there was no such harm in this case but it will be interesting to follow it to its conclusion. Many speak of how expensive behavioral therapies for autism are but the costs of this biomedical quackery with no sound scientific evidence to suggest that it provides any benefit dwarf the cost of providing intensive instruction.

A Radical Behaviorist

Observations and comments about autism, behavior, and learning.
Bill Ahearn, Ph.D., BCBA-D

Bill Ahearn is Director of Research at the New England Center for Children, a private nonprofit educational facility for children with autism.

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