I had never read of this before, and just did a bit of reading...
Seems like this is a controversial disorder in which patients claim to become ill from environmental exposure to low levels of largely petroleum-based and often unrelated chemicals, including cleaning products, detergents, diesel exhaust, formaldehyde, plastics, carpets, epoxy, pesticides, and some synthetic and natural fragrances. The symptoms are reported to be induced by environmental chemicals at doses far below those usually harmful to most persons.
Among its symptoms, are a perceived hypersensitivity to the smell of chemicals, nausea, dizziness, headache, upper respiratory discomfort, runny eyes, chest and throat pain, arthralgia, dyspepsia, fatigue, lack of concentration, memory difficulties, depression, anxiety, mood disruption, and a range of other cognitive and psychological disturbances.
At present, no standard medical tests have been identified that correlate with the numerous multisystem complaints of MCS patients. The patients believe they are sick and are not malingering. According to the APA, the diagnostic criteria are "excessive thoughts, feelings or behaviors related to the physical symptoms or health concerns with at least one of the following: ongoing thoughts that are out of proportion with the seriousness of symptoms; ongoing high level of anxiety about health or symptoms; excessive time and energy spent on the symptoms or health concerns."
However, no clear link has emerged among self-reported MCS symptoms and widely accepted objective measures of physiological dysfunction, and no clear dose-response relationship between exposure and symptom reactions has been observed.
That is fascinating. It appears that it is all in their head.
Makes me wonder if a person can be brought to understand that it is all in their imagination. If they could only understand this was all their mind, I wonder if they still would have applied for VAD.