- BIOETHICS FORUM ESSAY
NIMH Chelation and Autism Study: The Sound and the Fury
The role of news wire services is to transmit news to media outlets, but the Associated Press perhaps unwittingly went beyond its job description earlier this month with an article titled, “Fringe Autism Treatment Could Get Federal Study.” It ignited a firestorm.
“Pressured by desperate parents,” the article began, “government researchers are pushing to test an unproven treatment on autistic children, a move some scientists see as an unethical experiment in voodoo medicine.”
The story described the controversy over a clinical trial proposed by the National Institute of Mental Health to find out if dimercaptosuccinic acid (DMSA), an oral chelating substance, is useful for treating autism in children. The therapy, which removes mercury and other metals from the body, is already used as an alternative remedy for autistic children whose parents believe that mercury – in particular, mercury from a preservative in vaccinations – causes autism. An estimated 3,000 children in the United States have been given DMSA.
The study itself is not news. It was approved in 2006 and suspended in 2007, after new scientific data found that DSMA could cause brain damage in rats. Meanwhile, the study proposal has been undergoing additional review. The review process included approval of an application for an investigational new drug, which the Food and Drug Administration granted in May.
Immediately following the AP dispatch, a brushfire of debate raged through a variety of media outlets. “Autism bloggers have been expressing their opinions – and the opinions range from anger to joy,” wrote Lisa Jo Rudy on About.com, an online source of practical information.
Nature weighed in last week with an online news piece devoted to criticism of the proposed study from the American Academy of Pediatrics and some doctors. “Critics say the trial will put children at risk for what is certain to be no medical gain,” the article said.
Then came the criticism of the critics. In a comment on the Nature article, Robin Nemeth expressed the view that “the possible benefits of this procedure have been played down by the medical establishment, and the risks played up.”
Writing in The Huffington Post, Lisa Conte took Nature to task for promoting “some fallacies in a condescending and inappropriate manner about mercury as a possible cause, or contributing cause, of autism to those families desperately seeking answers to a now epidemic disease.”
In a statement issued after the AP article, the National Institute of Mental Health defended its proposed chelation study on the grounds that doctors are already using it to treat autistic children, despite little scientific data on its safety or usefulness. “Researchers are trying to develop scientific evidence to determine whether chelation therapy is safe and effective for this condition,” the statement said.
The study is now under ethics review by the Department of Health and Human Services. For clinical trials with minors, Subpart D of the Department’s regulations stipulates the criteria that institutional review boards must use to determine whether the trial’s risks justify its potential benefits.
What are those risks? The most troubling risk, based on the rat study, is brain damage to children, whose developing brains are more vulnerable than adults’ brains to harm. Another risk is nutritional deficiency. Chelation therapy can remove the good with the bad – the beneficial minerals with the toxic chemicals like mercury, says Dr. Ray Barfield, a pediatric oncologist and associate professor of pediatrics and Christian philosophy at Duke University. “The drug is by no means without possible significant side effects,” he said.
And the benefits? The children in the study are unlikely to benefit, says Dr. Carmen Paradis, a physician in the department of bioethics at the Cleveland Clinic. Any benefit will be for the greater good of children with autism in the form of more scientific clarity on what might contribute to autism and what might help.
“The informed consent process has to be very good,” said Dr. Paradis. “Parents have to understand that their children are not expected to benefit, but that the study may help children in the future.”