I sometimes think that those of us with MCS tend to be conditioned to react to anything that smells! However, research from the Karolinska Institute in Stockholm suggests that this is not the case. They set out to determine whether sufferers of MCS had an "increased odor-signal response in the odor-processing neuronal circuits". What they did find is that the subjects with MCS did process odours differently and that this process was only present when exposed to odours and not odourless air. Click here to read the article.