This article is from the Amalgam-Related Illness FAQ, by Leif Hedegard.
Reports stating that groups of people, suspecting that they have a (non-allergic-) amalgam-related illness, have reduced their symptoms, by up to 80%, after removing their amalgam-fillings have been presented (Lichtenberg 1993, Lindqvist 1996, Siblerud 1990). Also presented are case-reports of people regaining their health after amalgam-removal (Barregard 1995, Godfrey 1990, Langworth 1996, Redhe 1994). It is not possible to definitely distinguish between a ceased poisoning, a placebo-effect, spontaneous recovery or biases due to the subjects potential desire to have his own view on the causation of his illness confirmed or due to his desire to please the investigator. Berglund (1995) has reviewed the case-reports of adverse effects to amalgam, available in the literature, and found that:
"Removal of amalgam was the common measure that led to improvement or cure"
In several countries there are patient organisations with members convinced that they have achieved a symptom reduction after amalgam removal.
Twelve months after a complete amalgam-removal the mercury levels in plasma and urine are reduced to about 50 % (Molin 1990) and 25 % (Begerow 1994, Molin 1990, Molin 1995) respectively of the levels that were present before the amalgam-removal.
There are reports suggesting that the amalgam-related illness has nothing to do with mercury or anything else in the filling material, but it is an "environmental somatization syndrome (ESS)" (Gothe 1995) or "such patients need... to address the core problems of their lives" (Bergman 1992) or "They have all had an early psychologic disturbance... Most of them find it difficult to express in words what they feel, and react instead with somatic symptoms to the mental stress that they experience. The illness they then develop is the one "offered" to them. In these cases it became amalgam illness" (Lindberg 1994). These reports points out the theoretical possibility of such a thing, but do not, in any way, prove that this is a fact.
It has been reported that somatization, as measured by the Minnesota Personality Inventory, has been found in 4 of 9 Hg-intoxicated individuals (Vroom 1972). Thereby somatization can be looked upon as a feature of Hg-intoxication. This would mean that the presence of somatization is not enough to exclude a Hg-intoxication as the cause of a personÂ´s symptom.
It could be that (some) people who are convinced they have an amalgam-related illness really do have other causes to their symptoms, it just hasn't been proven. Also it is not impossible that a patient develops parallel symptoms from psychological, amalgam-related and other causes.
Some doctors do not believe in amalgam-related illness but rather would recommend psychological therapy / psychiatric treatment / medical treatment / odontological treatment (other than amalgam removal).
There are epidemiological studies that found that groups of individuals with few or no amalgam-fillings were healthier than groups of individuals that had (more) amalgam-fillings (Kampe 1986, Siblerud 1990b , Siblerud 1994). Contrary to this there are studies that failed to show this (Saxe 1995, Ahlqwists 1988). Because of methodological problems they can not, alone or together, conclusively answer the question if there is a minority of the population that has or hasn't got a (non-allergic-) amalgam related illness. Ahlqwists report (1988), however, seems to give additional support to the conclusion (se section 3.1) that a majority or even a big minority (for example over 10-30 %) of the general amalgam-bearing population is probably not negatively health effected from their dental amalgam fillings.
Among the methodological problems, that these studies are afflicted with, are:
So which came first? Socio-economic group belonging, illness/health, (dys-) function, tooth loss... which gave rise to different amount of amalgam fillings or the amalgam fillings which gave rise to changed socio-economic group, illness/health, (dys-) function, tooth loss...? Correlation / lack of correlation does not prove a true effect / no effect, it only proves a correlation / no correlation. The mechanism can not easily be determined as there are more than one variable (amalgam per se and all the variables that makes individuals belong to a non (low)- or high number-amalgam group).
Also make sure to read these books: Poison in Your Teeth: Mercury Amalgam (Silver) Fillings...Hazardous to Your Health! and Mercury Detoxification by Tom McGuire