'Mass hysteria' afflicts girls at Mexican Catholic school

the sociopsychological phenomenon of the manifestation of the same hysterical symptoms by more than one person. It may begin when a group witnesses an individual becoming hysterical during a traumatic or extremely stressful event. A potential symptom is group nausea, in which a person becoming violently ill triggers a similar reaction in other group members.

"We will work with the girls in specific therapy as a follow-up," Victor Manuel Torres, under secretary of epidemiology for Mexico state, told reporters Sunday. "We must investigate if it is a case of social adversity."

"So far, the diagnosis is an epidemic conversion disorder, an illness known as mass hysteria," Torres said.

About 120 girls still show some or all symptoms of mass hysteria and are still at the school, he said.

The Roman Catholic school, a free establishment for 12- to 18-year old girls from poor families run by sister Margie Cheong, has come under fire since the case came to light.