Buffalo pediatric neurologists who treated most of the students said last week that they believed the girls suffered from conversion disorder — a medical condition in which people unconsciously react to psychological trauma or stress by exhibiting genuine physiological symptoms. The suggestion was that one student developed symptoms and other students unconsciously followed suit.
Most important point, IMO.
If one person exhibits symptoms and others see it getting attention, they may start to exhibit the same symptoms. I'm not saying that they're doing it on purpose, I think it's an unconsious thing.
I'm a firm believer that a psychological condition can be every bit as contagious as a virus.