List of mass hysteria cases

In sociology and psychology, mass hysteria (also known as *mass psychogenic illness*, *collective hysteria*, *group hysteria*, or *collective obsessional behavior*) is a phenomenon that transmits collective illusions of threats, whether real or imaginary, through a population in society as a result of rumors and fear (memory acknowledgement).

In medicine, the term is used to describe the spontaneous manifestation (production of chemicals in the body) of the same or similar hysterical physical symptoms by more than one person.

A common type of mass hysteria occurs when a group of people believe they are suffering from a similar disease or ailment, sometimes referred to as *mass psychogenic illness* or *epidemic hysteria*.

## Middle Ages

* According to an 1844 book citing an unnamed medical textbook, a nun in a French convent during an unspecified time in the Middle Ages inexplicably began to meow like a cat, shortly leading to the other nuns in the convent also meowing. Eventually all the nuns would meow together for a certain period every day, leaving the surrounding community astonished. This did not stop until the police threatened to whip the nuns.
* According to a 1784 author, a nun in a German convent in the 1400s began to bite her companions, and the behavior spread through other convents in Germany, into Holland and as far as Italy.

## 1500-1800

* The dancing plague of 1518 was a case of dancing mania that occurred in Strasbourg, Alsace (then part of the Holy Roman Empire) in July 1518. Numerous people took to dancing for days without rest, and, over a period of about one month, some of them died of heart attacks, strokes, or exhaustion.
* The Irish Fright took place in England and parts of Wales in December 1688 during the Glorious Revolution. False reports that Irish soldiers were burning and massacring English towns prompted a mass panic in at least nineteen counties, with thousands of people arming themselves and preparing to resist non-existent groups of marauding Irishmen.
* Salem witch trials (1692-1693) - In colonial Massachusetts, adolescent girls Abigail Williams, Betty Parris, Ann Putnam, Jr., and Elizabeth Hubbard began to have fits that were described by a minister as "beyond the power of Epileptic Fits or natural disease to effect." The events resulted in the Salem witch trials, a series of hearings which resulted in the execution of 20 citizens and the death of five other citizens of Salem Village, Massachusetts (present day Danvers, Massachusetts) and nearby towns who were accused of practicing witchcraft. The episode is one of America's most notorious cases of mass hysteria, and it has been used in political rhetoric and popular literature as a vivid cautionary tale about the dangers of isolationism, religious extremism, false accusations and lapses in due process.
* Würzburg 1749 - An outbreak of screaming, squirming, and trance in a nunnery led to the execution of a suspected witch.
* The Great Fear was a general panic that took place between 17 July and 3 August 1789, at the start of the French Revolution.

## 1800-1950

* Spring-heeled Jack - England, starting in 1837
* Basel and Groß Tinz "Writing Tremor Epidemic" (1892, 1904) - The right hand of a ten-year-old girl in Groß Tinz began trembling, which developed into full-body seizures that spread to 19 other students. A similar epidemic affected 20 in Basel, Switzerland. Twelve years later, the Basel school experienced another outbreak that affected 27 students. Legend of the first outbreak was said to have played a role.
* Montreal (1894) - Sixty students at a ladies' seminary suffered an outbreak of fits and seizures, some for as long as 2 months.
* Meissen "Trembling Disease" (1905–06) - An estimated 237 children were afflicted between October 1905 and May 1906.
* Halifax Slasher (1938) - The Halifax Slasher was the name given to a supposed attacker of residents, mostly women, of the town of Halifax, England in November 1938. The week-long scare began after two women claimed to have been attacked by a mysterious man with a mallet and "bright buckles" on his shoes. Further reports of attacks by a man wielding a knife or a razor followed. The situation became so serious that Scotland Yard was called in to assist the Halifax police. On November 29 one of the alleged victims admitted that he had inflicted the damage upon himself for attention. Others soon had similar admissions, and the Yard investigation concluded that none of the attacks had been real. Five local people were subsequently charged with public mischief offenses, and four were sent to prison.
* Bellevue, Louisiana (1939) - A girl developed a leg twitch at the annual homecoming high school dance. Attacks worsened and spread to friends over the next several weeks.
* Mad Gasser of Mattoon, Illinois, 1940s

## 1950-2000

* Seattle windshield pitting epidemic of 1954
* Tanganyika laughter epidemic (1962) - The Tanganyika laughter epidemic began on January 30, 1962, at a mission-run boarding school for girls in Kashasha, Tanzania. The laughter started with three girls and spread haphazardly throughout the school, affecting 95 of the 159 pupils, aged 12–18. Symptoms lasted from a few hours to 16 days in those affected. The teaching staff were not affected but reported that students were unable to concentrate on their lessons. The school was forced to close down on March 18, 1962. After the school was closed and the students were sent home, the epidemic spread to Nshamba, a village that was home to several of the girls. In April and May, 217 people had laughing attacks in the village, most of them school children and young adults. The Kashasha school was reopened on May 21, only to be closed again at the end of June. In June, the laughing epidemic spread to Ramashenye girls' middle school, near Bukoba, affecting 48 girls. Another outbreak occurred in Kanyangereka and two nearby boys schools were closed.
* June bug epidemic (1962) - The June bug epidemic serves as a classic example of hysterical contagion. In 1962 a mysterious disease broke out in a dressmaking department of a US textile factory. The symptoms included numbness, nausea, dizziness, and vomiting. Word of a bug in the factory that would bite its victims and cause them to develop the above symptoms quickly spread. Soon 62 employees developed this mysterious illness, some of whom were hospitalized. The news media reported on the case. After research by company physicians and experts from the US Public Health Service Communicable Disease Center, it was concluded that the case was one of mass hysteria. While the researchers believed some workers were bitten by the bug, anxiety was probably the cause of the symptoms. No evidence was ever found for a bug which could cause the above flu-like symptoms, nor did all workers demonstrate bites.
* Welsh, Louisiana (1962) - With students' sexual activity under close scrutiny by school officials, and following rumors of mandatory pregnancy tests, 21 girls and one boy in grades six to eleven were affected by seizures and other symptoms over six months.
* Blackburn, England (1965) - In October 1965 at a girls' school in Blackburn, several girls complained of dizziness. Some fainted. Within a couple of hours, 85 girls from the school were rushed by ambulance to a nearby hospital after fainting. Symptoms included swooning, moaning, chattering of teeth, hyperpnea, and tetany. A medical analysis of the event about one year later found that outbreaks began among the 14-year-olds, but that the heaviest incidence moved to the youngest age groups. There was no evidence of pollution of food or air. The younger girls proved more susceptible, but disturbance was more severe and lasted longer in the older girls. Using the Eysenck Personality Inventory, those affected had higher scores for extroversion and neuroticism. It was considered that the epidemic was hysterical, that a previous polio epidemic had rendered the population emotionally vulnerable, and that a three-hour parade, producing 20 faints on the day before the first outbreak, had been the specific trigger.
* Mount Pleasant, Mississippi (1976) - School officials suspected drug use after 15 students fell to the ground writhing, but no drugs were found and hysteria is assumed to be the culprit. At one point, one third of the school's 900 students stayed home for fear of being "hexed".
* Malaysia (1970s–1980s) - Mass hysteria occurred in Malaysia from the 1970s to the 1980s. It affected school-age girls and young women working in factories. The locals have explained this outbreak as "spirits" having possessed the girls and young women.
* Hollinwell incident (1980) - Around 300 people, mostly children, but including adults and babies, suddenly suffered fainting attacks, nausea and other symptoms. The Hollinwell incident remains one of the prime examples of mass hysteria.
* The 1983 West Bank fainting epidemic was a series of incidents in March 1983 in which 943 Palestinian teenage girls, mostly schoolgirls, and a small number of IDF women soldiers fainted or complained of feeling nauseous in the West Bank. Israel was accused of using chemical warfare to sterilize West Bank women while IDF sources speculated that a toxic substance had been employed by Palestinian militants to stir up unrest, but investigators concluded that even if some environmental irritant had originally been present, the wave of complaints was ultimately a product of mass hysteria. This conclusion was supported by a Palestinian health official, who said that while 20% of the early cases may have been caused by the inhalation of some kind of gas, the remaining 80% were psychosomatic.
* San Diego (1988) - The US Navy evacuated 600 men from barracks; 119 were sent to San Diego hospitals with complaints of breathing difficulty. No evidence of toxins, food poisoning, or any other cause was found.
* Kosovo student poisoning, 1990 - Zoran Radovanović, a professor in the Faculty of Medicine in Kuwait argues in an article for the European Journal of Epidemiology that the "Kosovo Student Poisoning" that affected at least four thousand, mostly ethnic Albanians, was a product of mass hysteria.
* Belgium (June 1999) - Soft drink giant Coca-Cola withdrew 30 million units of its product from sale after more than a hundred people in Belgium and northern France complained of cramps, nausea and other problems after consuming the soft drinks. Testing found no evidence of tainted product and the incident was reported to be a panic, perhaps fueled by the discovery of dioxins in Belgian meat, which had brought down the national government earlier that year.

## 2000s

* North Carolina (2002) - Ten girls developed seizures and other symptoms at a rural high school in North Carolina. Symptoms persisted for five months across various grade levels. Incidents tended to happen outside of class, with half of all incidents estimated to have occurred around lunch hour. Half of the affected were cheerleaders or former cheerleaders.

* "*Strawberries with Sugar* virus" (2006) - In May 2006, an outbreak of the so-dubbed Morangos com Açúcar Virus (Strawberries with Sugar virus) was reported in Portuguese schools, named after the popular teen girl's show *Morangos com Açúcar* (*Strawberries With Sugar*). 300 or more students at 14 schools reported similar symptoms to those experienced by the characters in a then recent episode where a life-threatening virus affected the school depicted in the show. Symptoms included rashes, difficulty breathing, and dizziness. The belief that there was a medical outbreak forced some schools to temporarily close. The Portuguese National Institute for Medical Emergency eventually dismissed the illness as mass hysteria.
* Mexico City (2007) - In 2007 near Chalco, a working-class suburb of Mexico City, mass hysteria resulted in a massive outbreak of unusual symptoms suffered by adolescent female students (600) at Children's Village School, a Catholic boarding-school. The afflicted students had difficulty walking and were feverish and nauseated.
* Vinton, Virginia (2007) - An outbreak of twitching, headaches and dizziness affected at least nine girls and one teacher at William Byrd High School. The episode lasted for months amid other local public health scares.
* Afghanistan (2009–) - Starting around 2009, a spate of apparent poisonings at girls' schools across Afghanistan began to be reported, with symptoms including dizziness, fainting, and vomiting. The United Nations, World Health Organization and NATO's International Security Assistance Force carried out investigations of the incidents over multiple years, but never found any evidence of toxins or poisoning in the hundreds of blood, urine, and water samples they tested. The conclusion of the investigators was that the girls were suffering from mass psychogenic illness. Despite these findings, Afghan officials often blame the incidents on the Taliban, accusing them of contaminating the school's water supply or using poison gas.
* Brunei (2010) - In April and May 2010, incidents of mass hysteria occurred at two all-girls secondary schools in Brunei. The most recent notable event happened on the 24 April 2014 in a public secondary school. The phenomenon caused a wave of panic among many parents, educators, and members of the community. Some of the students affected by the phenomenon claimed to have been possessed by spirits, or jinn, displaying histrionic symptoms such as screaming, shaking, fainting, and crying.
* LeRoy, New York (2011–12) - In late 2011, 12 high school girls developed Tourette-like symptoms. Their school was tested for toxins, and all other factors for their symptoms were ruled out. The case, and some of the girls and their parents, gained national media attention. In January 2012, several more students and a 36-year-old adult female came forward with similar symptoms. They were all diagnosed with conversion disorder.
* Sri Lanka (2012) - From November 15–20, 2012, incidents of mass hysteria occurred at 15 schools in Sri Lanka. More than 1,900 school children of 15 schools in Sri Lanka and five teachers were treated for a range of symptoms that included skin rashes, vomiting, vertigo, and cough due to allergic reactions believed to be mass hysteria. It originated at the Jinaraja Balika Vidyala in Gampola, Central Province on November 15, 2012 when 1,100 students were admitted to hospital with a range of symptoms that included skin rashes, vomiting, vertigo and coughing. Later, authorities had to close down the school for 3 days. After that on November 16–19 there were more reports of students from other parts of the country showing similar symptoms.
* Charlie Charlie panic (2015) - Four teens in Tunja, Colombia were hospitalized, and several in the Dominican Republic were considered "possessed by Satan" after playing the Charlie Charlie Challengeviral game.
* 2016 clown sightings - Sightings of people in evil clown costumes in the United States, Canada, and 18 other countries were dismissed as a case of mass hysteria, stating that a fear of clowns (which is common in children and adults) may be an underlying cause. The website *Vox* likewise claimed that "The Great Clown Panic of 2016 has been perpetuated by pretty much everyone except actual clowns."
* Emirates Flight 203, September 2018 - 106 of 521 passengers on a 14-hour flight from Dubai to New York reported symptoms including coughing, sneezing, fever, or vomiting. The pilot notified airport ground staff, and personnel from the U.S. Centers for Disease Control and Prevention met and quarantined the plane in New York and evaluated passengers, 11 of whom were sent to the hospital. A few passengers on the "flight from hell" turned out to have common colds or flu, with the other passengers coming to the belief that they were also sick after observing those around them
* Bee dance all teh way auditory hallucinations, April 2019 - A server on the Discord app used the gif function sanctioned by the app. There was a gif of users from the game Wizard 101 displaying a dance that this server could "hear" when on mobile.