Epidemic hysteria is also known as , epidemic hysteria, mass psychogenic illness, or collective obsessional behavior. This psychiatric condition is manifested in various forms such as laughing, dancing, fainting, and having skin rashes. Simon Wessely, a British psychiatrist, suggested that this phenomenon has five general characteristics: sudden appearance of abnormal behavior which cannot be attributed to physical illness, manifested by a group of people who would not normally engage in such deviancy, does not include deliberate provocation such as those observed in religious practices, does not include practices meant to achieve a goal such as fashion crazes and riots, and the relationship between the affected individuals must not be purely coincidental as they belong to a particular community or group. Wessely furthered that women are more prone to epidemic hysteria as they are often exposed to more stressors than men. The hypothesized causes include widespread anxiety, the ability of the brain to make the body believe that it is suffering from a particular sickness, and socio-emotional pressures.
There have been various accounts of mass hysteria throughout history. In the middle ages, a nun in Germany repeatedly bit other nuns and this biting epidemic spread to other nuns, through other convents even as far as Holland and Italy. In 1894, 60 students in Montreal suffered from seizures for two months. In 1939, a girl in Bellevue, Louisiana manifested a leg twitch which spread to her friends over several weeks. In September 2018, 106 passengers who flew from Dubai to New York were coughing, sneezing, and vomiting. Physicians concluded that only some of them merely had the common flu while the others believed that they were also sick after observing the symptoms of the other passengers.