US researchers call off controversial autism study

[September 18, 2008]  CHICAGO (AP) -- A government agency has dropped plans for a study of a controversial treatment for autism that critics had called an unethical experiment on children.

The National Institute of Mental Health said in a statement Wednesday that the study of the treatment -- called chelation -- has been abandoned. The agency decided the money would be better used testing other potential therapies for autism and related disorders, the statement said.

The study had been on hold because of safety concerns after another study published last year linked a drug used in the treatment to lasting brain problems in rats.

Chelation (kee-LAY'-shun) removes heavy metals from the body and is used to treat lead poisoning. Its use as an autism treatment is based on the fringe theory that mercury in vaccines triggers autism -- a theory never proved and rejected by mainstream science. Mercury hasn't been in childhood vaccines since 2001, except for certain flu shots.

But many parents of autistic children are believers in the treatment, and NIMH agreed to test it.

The researchers had proposed recruiting 120 autistic children ages 4 to 10 and giving half a chelation drug and the other half a dummy pill. The 12-week test would measure before-and-after blood mercury levels and autism symptoms.

The study outline said that failing to find a difference between the two groups would counteract "anecdotal reports and widespread belief" that chelation works.

In canceling the study, the agency noted it would take another year to review of the study and three years to do it. In the meantime, the agency said it was likely that other research would "provide deeper understanding of the causes of autism and more refined avenues for developing treatments."

"This was a wise and careful decision," said Ellen Silbergeld of Johns Hopkins University's Bloomberg School of Public Health, who had been invited to comment on the study during an earlier review. "It is to be hoped that the NIMH will continue its commitment to research into preventable risks for autism spectrum disorders."

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On the Net:

National Institute of Mental Health: http://www.nimh.nih.gov/

[Associated Press; By CARLA K. JOHNSON]

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