Almost as an article of faith, pseudomedicine supporters and believers reject the idea of psychological illness. Everything must have an external cause, which can be treated by appropriate magic. Nothing can come purely from within a person. This philosophy conflicts directly with the concept of helping the body to heal itself, because if the body has the power to maintain its own wellness, as stated by many pseudomedicine believers, then surely it must also have the power to harm itself. Logic, of course, has little to do with faith in voodoo.

One consequence of the belief that every illness is externally caused is the irrational fear of "chemicals". The fact that the only environment free of chemicals is a vacuum (or a high-temperature plasma) is irrelevant. Chemicals are bad. More chemicals make things worse. Drugs are chemicals. Herbs, spices, philtres, charms from the medicine man, vitamins and the chelating agents used by quacks to remove chemicals are, of course, not chemicals. Did I mention logic and pseudomedicine? Sometimes this fear of chemicals is focused on a single element or compound like mercury, fluoride or aspartame, which is blamed for a wide range of illnesses. Sometimes it is a particular class of chemicals, as in the almost insane generalised opposition to vaccines, anti-depressants and ADHD drugs.

This fear of chemicals reaches its absurd nadir in the nonsense of "Multiple Chemical Sensitivity", or "MCS". In this ailment, the patient is badly affected by a vast range of unrelated chemicals which produce an equally large range of symptoms and cause all known diseases. I am a exaggerating there, of course. The range of symptoms produced is in fact quite vague and non-specific, and condense down into a generalised fear of odours and unspecified (and unspecifiable) chemical compounds. This fear is encouraged by people with vested interest in "cures" and "treatments" for MCS, and broadcast widely by people who are ignorant of chemistry, biology, medicine and many other sciences.

If someone says that they cannot leave their house because they fear some unspecified awful circumstances, we say that they are agoraphobic and offer the appropriate counselling, medication and behavioural treatment. If someone says that they cannot leave their house because they might be eaten by the giant spiders that nobody else can see, we would offer a different diagnosis and offer treatments appropriate for this particular psychological disorder. If someone says that they can't leave their house because of the clouds of toxic gasses that nobody else can see or detect, we might ask how this differs from the spider story.

One remarkable aspect of MCS is that the disease itself causes the symptoms, and any attempt to point out that these symptoms are indistinguishable from those of well-known psychiatric disorders results in accusations of denial of the reality of MCS. When it is shown that MCS sufferers look, act and behave identically to people with anxiety disorders the response is "You would be anxious if you had MCS". When it is demonstrated that MCS sufferers are just like people with depressive illnesses, the response is "MCS would make you depressed, too". When parallels are drawn between phobias and MCS, the response is "You would be frightened too if you had been poisoned. Are you calling me paranoid?". When research indicates that people with MCS are just like, and may even be identical with, the sort of people who are susceptible to the implantation of false memories, the response is "Why are you saying that all MCS sufferers have been sexually abused?". When something looks exactly like something else and no reason can be found for it to be any different, then it is reasonable to assume that it is the same thing. MCS looks like anxiety disorder and phobia. There is little reason to think that it is anything else.

None of this denies the reality of MCS, except to someone who does not recognise that psychiatric and psychological disorders are real. There is no shame in admitting to these sorts of problems, and there are methods of treatment which work. A person who cannot go to work because MCS makes it impossible to breathe the air in an office is no less impacted or disadvantaged than someone who is claustrophobic and cannot work because of a fear of elevators or an agoraphobic who cannot work because it is impossible to leave the house without a panic attack

Lying about the origin of MCS benefits nobody except the quacks who run MCS clinics or who offer to use chemicals to pretend to chelate or extract the "toxins" from the affected people. As none of these "cures" address the real problem, they are merely cruel tricks being played on people with real disorders. But why should this branch of quackery differ from any other?

By Peter Bowditch.

Visit the Australian Skeptics website at www.skeptics.com.au to read more.

The opinions expressed here are those of the authors and do not necessarily reflect the position of Yahoo!7.