Autism and Mercury Data Reanalyzed - DeSoto and Hitlan

The issue of whether autism is caused in whole or in part by mercury or mercury based preservatives (Thimerosal) in vaccines has been one of the most intense of the many divisive issues associated with autism disorders. I personally have never accepted that the available evidence, as interpreted by professional authority, demonstrated such a connection but I try to keep an open mind in the event that new evidence emerges, or new studies are done which demonstrate a mercury-autism connection.

Failure to keep an open mind is essentially a failure to think, to reassess conclusions in light of new evidence. In some ways a closed mind is also a worship of the past when a person did think through the issues based on the evidence available at that time and a lack of confidence in one's current analytic abilities. It is important for children with autism, now and those yet to be born, that any new relevant data which might help us understand causal factors giving rise to autism be understood and if possible preventions, treatments and cures developed. If mercury is a factor then we would be grossly negligent to ignore evidence of that factor solely because we had examined the issue in the past and failed to find the connection.

In a new article published in the November 2007 issue of the Journal Of Child Neurology M. Catherine DeSoto Ph D and Robert T. Hitlan Ph D, both of the Department of Psychology at the University of Northern Iowa, have gone back and reanalyzed previous data from an important previous study and concluded that contrary to the original study the data it reported did in fact support a connection between mercury and autism.

In Blood Levels of Mercury Are Related to Diagnosis of Autism: A Reanalysis of an Important Data Set DeSoto and Hitlan conclude that a significant relation does exist between the blood levels of mercury and diagnosis of an autism spectrum disorder:

The question of what is leading to the apparent increase in autism is of great importance. Like the link between aspirin and heart attack, even a small effect can have major health implications. If there is any link between autism and mercury, it is absolutely crucial that the first reports of the question are not falsely stating that no link occurs. We have reanalyzed the data set originally reported by Ip et al. in 2004 and have found that the original p value was in error and that a significant relation does exist between the blood levels of mercury and diagnosis of an autism spectrum disorder. Moreover, the hair sample analysis results offer some support for the idea that persons with autism may be less efficient and more variable at eliminating mercury from the blood.

Undoubtedly the DeSoto and Hitlan article will give rise to a response, hopefully from Patrick Ip and his colleagues who authored the 2004 study Mercury Exposure in Children With Autistic Spectrum Disorder: Case-Control Study. There is a good possibility of calm objective discussion of this article and its conclusions amongst scholars. Amongst internet bloggers and to some extent mainstream media commentators, emotional, ideologically based criticism will be the more likely result. As one who sits in neither camp in the great autism mercury war I agree with the statement in the DeSoto and Hitlan abstract that if there is any link between autism and mercury, it is absolutely crucial that the first reports of the question are not falsely stating that no link occurs.

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