Chelation Study for Autism Called Off

Controversial Trial Too Risky, Panel Says

Medically Reviewed by Louise Chang, MD on September 18, 2008
From the WebMD Archives

Sept. 18, 2008 -- Federal officials have abandoned a proposed study of a controversial alternative therapy for autism, leaving parents who believe in the treatment disappointed and angry about the move.

In a statement released Wednesday, the National Institute of Mental Health (NIMH) says its investigators would not go forward with a trial of chelation (pronounced kee-LAY-shun) therapy that has been discussed for the past two years.

The decision was made after the federal review board that originally approved the study reversed its position.

The study had reportedly been on hold since last year when animal trials linked a specific chelation treatment to brain damage in rats.

"The Board determined that there was no clear evidence for direct benefit to children who would participate in the chelation trial and that the study presents more than a minimal risk," according to the NIMH statement.

Chelation for Autism

Chelation therapy involves the administration of agents to remove heavy metals from the blood, usually, but not always, by intravenous infusion.

The therapy has been approved for more than 50 years for the treatment of lead poisoning, but it is not approved for the treatment of autism.

Nevertheless, many parents who believe their children's autism was caused by mercury exposure from a preservative once common in childhood vaccines have embraced chelation therapy.

"Our phones have been ringing off the hook since this was announced," Rebecca Estepp of the autism support group Talk About Curing Autism tells WebMD.

"We are dumbfounded and saddened that this study of a promising autism treatment will not happen. The government has pulled the rug out from under us with no explanation."

Estepp, whose 10-year-old son is autistic, says she knows of thousands of children who have improved and even had their autism symptoms disappear following chelation therapy.

"Do we have to have thousands more before they take us seriously?" she asks. "When does the anecdotal evidence get so large that they have to listen to us?"

A Chelation Death Reported

The use of chelation therapy as a treatment for autism has been linked to at least one death in 2005 of a 5-year-old boy who was treated with an agent that is not widely used in children.

In the statement released yesterday, NIMH officials noted that approval by the Department of Health and Human Services (DHHS) was needed to proceed with the trial. But NIMH will not ask the DHHS to review the study protocol, a process that could take as long a year.

"Given the time and resources required for this additional approval process, NIMH has decided to use its intramural program to test other interventions for autism and will not pursue the required DHHS review," the statement reads.

Physician Paul Offit, MD, who this month published a book that is critical of alternative treatments, applauds the NIMH decision.

"None of the biological and epidemiological data support the notion that mercury from the thimerosal in vaccines causes autism," he tells WebMD. "So you could argue that this study was unethical because there was no biological basis for doing it."

In his book Autism's False Prophets: Bad Science, Risky Medicine, and the Search for a Cure, Offit examines many past and present alternative treatments for autism.

He tells WebMD that none of the treatments has held up to scientific scrutiny, but many remain popular because parents have few other places to turn.

"Classical Western medicine does not offer much for the treatment of autism," he says. "These fringe therapies have appeal because there is not much else out there."

Offit adds that very young children with mild symptoms of autism often get better on their own later in childhood, which may explain why many parents believe so strongly that alternative treatment work.

"There is a natural wax and wane with this disorder," he says. "Symptoms that seem very bad between the ages of 2 and 5 may get much better between the ages of 6 and 10."

He adds that promising, conventional research on autism gets little attention because of the focus on alternative therapies.

He cites as an example the identification of the specific genes and genetic mutations associated with autism.

"This may well lead to treatments in the future, but you never hear about this kind of study because the anti-vaccine people have taken this story hostage to the detriment of children with autism," he says.