Epidemic hysteria, known by multiple synonymous terms, including mass hysteria, mass psychogenic illness, and mass sociogenic illness, has been defined as a constellation of symptoms suggestive of organic illness, but without an identifiable cause, that occurs between two or more people who share beliefs related to those symptoms (1). Rather than being viewed as a collection of people suffering...

The conventional view would appear to define hysterical symptoms (whether so-called conversion symptoms or hysterical dissociation) in terms of a number of features. The first is the occurrence of a symptom which, if taken at face value, would be an indication of some underlying pathological process; yet no pathology of a conventional kind can be elicited, and the presence of such pathology (wh...