Chelation is a type of therapy in which a man-made amino acid, called EDTA, is added to the blood, and it has been used to treat heavy metal poisoning. It is used by many as alternative medical therapy for children with the condition.
However, another study published last year linked EDTA used in the treatment to lasting brain problems in rats thus making the government cancel the current study. .
NIMH, a part of the U.S. National Institutes of Health, said in a statement on Wednesday that it initially agreed to carry on the study in 2006 after a large number of parents of autistic children advocated the theory that autism is triggered by exposure to mercury, a heavy metal, from childhood vaccines.
The theory was never proved and is rejected by a large group of scientists as mercury hasn't been in childhood vaccines since 2001, except for certain flu shots, according to the U.S. Centers for Disease Control and Prevention.
The government agency said in a statement that it now plans to use the money for the study on testing other potential therapies for autism and related disorders.
