The pathophysiologic and psychologic mechanisms that may contribute to the development and maintenance of this disorder have still not been definitively elucidated. No consensus has yet been reached for a case definition. All proposed definitions differ by some key criteria. Besides the lack of a single case definition, several methodological problems limit the interpretation of published MCS research. Many proposed outcome measures also require validation.
Survey data suggest that odor related symptoms are common in the general population.
The prevalence of pre-existing and concurrent psychiatric disease remains highly controversial. 28 Research suggests an excess of symptoms of psychological distress consistent with anxiety and depression in many, but not all MCS patients. 16 Evidence also supports an etiologic role for conditioned response. Indeed, modern medicine no longer supports a mind-body dichotomy. It is neither helpful nor appropriate to address the problem solely by hypotheses that emphasize malingering or a desire for compensation.