The Ripon 'ripple of anxiety' and mass hysteria | Pete Etchells

When up to 40 children collapsed and suffered nausea at a Yorkshire school yesterday, media outlets were keen to diagnose 'mass hysteria'. But what is it?

One particularly strange story cropped up in the news yesterday: around 40 children were treated at a school in Ripon, Yorkshire, after collapsing during a Remembrance Day service. The trouble is, no one's quite sure why it happened. Although a hazardous materials team were called in, no obvious toxic substances were found. The assembly room was warm, apparently, so the mass fainting could have been down to everyone overheating, but an alternative explanation that some media outlets are putting forward is that it was simply a case of 'mass hysteria'.

Mass hysteria is a fairly broad term that covers a few different types of collective delusions, so it might be more accurate to characterise the Ripon event as a case of 'mass sociogenic illness' or MSI - described in a 2002 paper by Robert Bartholomew and Simon Wessely as situation in which signs or symptoms of an illness spread rapidly through a group of people, and which don't have any sort of organic cause. In a seminal paper in 1987, Wessely described two different types of MSI: mass anxiety hysteria, in which the event lasts a short time and, as the name suggests, manifests mainly in symptoms of anxiety and fear, and mass motor anxiety, which tends to be much more prolonged and manifests as a disorder of movement.