MCS: A Brief Literature Review

by Patrick Casanova

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It is often claimed by critical scientists that the peer-reviewed literature substantiates the view of psychosocial etiology regarding "Multiple Chemical Sensitivity" (MCS).

Multiple Chemical Sensitivity (MCS) is a controversial illness in which sufferers are alleged to be up to 1,000 times more sensitive to common everyday chemicals than the healthy population.

Some maintain the etiological view of organicity, whereas others maintain the view of psychosocial etiology. This report will be a brief literature review, showing which etiological view predominates, as well as briefly criticizing articles that support a psychosocial view.

From 1945 to 2002 there were 694 published, peer-reviewed articles on MCS. Of these, over 50% support the organic view, whereas less than 25% support a psychosocial view (Donnay, 2002). Over half of these articles are just since 1992 (Donnay, 2002). For example, in 1999 the British Health and Safety Executive commissioned a report on MCS that concluded MCS is an organic disease. The report was carried out by the Institute of Occupational Medicine and endorsed by the Department of Health (Independent, London, March 19, 1999).

Also in 1999, 89 clinicians and researchers “with extensive experience in, but widely differing views of, MCS” agreed upon a definition for MCS and 2 years later a review described the definition of MCS as the best current definition (Heuser et al., 1999; McKeown-Eyssen et al, 2001).

The critical articles contain methodological and logical flaws such as assuming psychological symptoms equal psychosocial etiology, overstating psychological interventions, recycling previously-stated opinion, among others (including, in 7 separate articles, attributing the results of non-MCS sufferers to MCS sufferers) (Ashford and Miller 1998; Dudley, 1998).

Critical position statements from AAAAI and ACOEM ignore/omit hundreds of articles that support an organic view, particularly the key articles such as those by Pall, Donnay, Heuser, Dudley, and other great scientists.

What about the other organizations? Their position statements too contain no reference to the key articles in the literature and are either outdated or have been retracted:

-- The California Medical Association (CMA) reclassified its anti-MCS position statement of 1985 as "a historical document only."

-- The American College of Physicians now has no position statement on MCS.

-- In 1992 the AMA published a position statement critical of clinical ecology and the notion that MCS is organic.

Subsequently, the position statement was retracted when, in 1994 the AMA, EPA, ALA, and CPSC (Consumer Product Safety Commission) wrote in a joint statement that, "The current consensus is that in cases of claimed or suspected MCS, complaints should not be dismissed as psychogenic, and a thorough workup is essential." (Donnay, 1999)

Thus there appeared to be a major shift of medical opinion with 3 major scientific organizations (AMA, EPA, ALA) condemning the dismissal of MCS as psychosocial.

However, despite the clear reference to "current consensus" in the joint statement, it is difficult to ascertain whether or not the AMA as a whole supports the organic view. Arthur Elster, M.D., AMA Director, wrote to me saying, "The AMA does not have a consensus opinion on this issue."

SUMMARY AND CONCLUSIONS:

In any event, none of the position statements of the past or present contain any references to the key articles mentioned earlier and omit hundreds that support an organic etiology. The use of critical position statements as evidence against the organic view is without merit.

The weight of the peer-reviewed literature is in favor of the organic view with the majority of MCS researchers maintaining an organic view.

References