Research Chelation Therapy

Earlier this week, the Associated Press reported that Tom Insel, the director of the National Institute of Mental Health (NIMH), supports testing the effectiveness of chelation therapy on children to see if it can be proved safe and effective. The autism blogosphere lit up, and advocates of chelation therapy were elated. But as with all things concerning autism, alas, the story is far more complicated than it seems.

The chelation study was first approved by NIMH in 2006. In February 2007, a study showed that giving chelation to rats who weren’t suffering from heavy-metal poisoning caused permanent cognitive impairment. Whoa. That sent NIMH back to more risk-benefit analysis. It filed an application with the Food and Drug Administration to study chelation as an investigational new drug (an IND, in FDA-speak). And keep in mind that the dynamic of testing chelation on rats involves differing variables than on human beings. The findings are not “definitive” at all.

The knowledge gleaned from the study will be limited, since only 120 children are to be enrolled.  Half will get a chelating agent for 12 weeks and the other half, a placebo. The children’s blood mercury levels and autism symptoms will be monitored along the way. That’s too few subjects to get a clear sense of whether or not chelation works, though it’s better than what we’ve got now.