Outbreak of mass hysteria?

A dozen teenage girls have shown symptoms of tics at a Leroy high school. The administrators will say there has been a diagnosis, but they won't say what.

From the news story:

Dr. Gregory Young said that as a matter of principle he didn't want to see the girls "labelled" by what their doctor has found.
Young, from the NYS Department of Health, said the cause (or causes) isn't anything environmental, it isn't anything a person "catches," it doesn't come from exposure to anything, or from anything ingested. The cause, he said, isn't from prescribed drugs or illicit drugs.
He can't say what the cause is, but he tried to reassure parents that it's safe to send their children to school.

I am pulling for mass hysteria. Writing on the phenomenon in general, Gary Small, a psychiatrist:

Most often, the outbreaks afflict children and teenagers, girls more than boys, and fainting and hyperventilation are the most common symptoms. Occasionally the illness persists for days; but usually, once the afflicted crowd disperses, symptoms tend to disappear, probably because they are only contagious when new victims observe others falling ill. Rumors about the cause of these outbreaks tend to spring up throughout the communities....

Some people are more likely to endorse a far-fetched or outlandish cause for their illness than to consider the mind-over-matter theory.