Three results, in order. First, documented illness before awareness in hundreds of people: unexplained symptoms on a dated medical record, followed by later discovery of an exposure recorded independently. Second, a measurable biological profile shared by people who developed MCS after different exposures and absent in matched controls. Third, objective physiological change under blinded, individualized exposure that does not occur under matched sham. Each is achievable. None has been done.
Thirty years of research produced more than 350 studies, dozens of proposed markers and no accepted biomarker, according to the USC/Johns Hopkins evidence map. Study number 352 asking the same questions will not change that. The questions have to change.
Illness before awareness attacks the strongest psychological argument directly: expectation cannot start an illness in someone who does not know an exposure has occurred. Corroborated chronology in a large group would settle onset causation as far as observational evidence can. A small number would tell us the pattern is rarer than believed. Either is progress.
The systems phenotype attacks the mechanism question. Measure sensory thresholds, receptor responsiveness, sudomotor function, orthostatic physiology, small fibers, inflammatory and mast-cell markers and selected genetics in the same characterized people, and ask whether a profile emerges. One marker has failed for thirty years; a profile has never been tried.
The definitive exposure study attacks the trigger question. Not "did the perfume make you feel sick" but: individualized trigger against matched sham, randomized and repeated, participant blinded where feasible, continuous objective physiology, delayed follow-up, medical supervision. It could distinguish stimulus-specific physiology, expectation, both or neither — which the 2006 literature, with its poor blinding and self-report outcomes, could not.
The research is designed so that it can return the other answer. If illness rarely precedes awareness, if no shared profile exists, if physiology does not differ from sham, the position on this site changes. That is what makes it a position and not a belief.
All three, in sequence: chronology first, phenotype second, causation testing third, with a fourth phase on recovery.
Environmental causation is proved by chronology, by phenotype and by blinded physiology. None of the three has been done properly. The registry is the machine for doing them, and it is built to be able to prove us wrong.