Medieval period The earliest studied cases linked with epidemic hysteria are the
dancing manias of the
Middle Ages, including
St. John's dance and
tarantism. These were supposed to be associated with spirit possession or the bite of the
tarantula. Those with dancing mania would dance in large groups, sometimes for weeks at a time. The dancing was sometimes accompanied by stripping, howling, the making of obscene gestures, or reportedly laughing or crying to the point of death. Dancing mania was widespread over Europe. Between the 15th and 19th centuries, instances of motor hysteria were common in
nunneries. The young women that made up these convents were sometimes forced there by family. Once accepted, they took
vows of chastity and
poverty. Their lives were highly regimented and often marked by strict disciplinary action. The nuns would exhibit a variety of behaviors, usually attributed to
demonic possession. They would often use crude language and exhibit suggestive behaviors. In the English translation of Hecker's
The Epidemics of the Middle Ages (1844), the translator and 18th century epidemiologist
Benjamin Guy Babington included a personal note of his in the Hysteria section of The Dancing Mania chapter. Babington's note recalled reading an uncited French medical journal that described a large convent of nuns in France that collectively began to meow like cats one day. The nuns meowed for long periods of time throughout the day, for several hours, until they were beaten with rods to cease the excessive meowing. Priests were often called in to
exorcise demons. They were characterized by (1) hysterical seizures of screaming and general violence, wherein tranquilizers were ineffective (2) trance states, where a worker would claim to be speaking under the influence of a spirit or
jinn and (3) frightened spells: some workers complained of unprecedented fear, or of being cold, numb, or dizzy. Outbreaks would subside in about a week. Often a
bomoh (medicine man) would be called in to do a ritual exorcism. This technique was not effective and sometimes seemed to exacerbate the MPI outbreak. Females and
Malay people were affected disproportionately. In June 1962, a peak month in factory production, 62 workers at a dressmaking factory in a textile town in the
Southern United States experienced symptoms including severe nausea and breaking out on the skin. Most outbreaks occurred during the first shift, where four fifths of the workers were female. Of 62 total outbreaks, 59 were women, some of whom believed they were bitten by bugs from a fabric shipment.
Entomologists and others were called in to discover the pathogen, but none was found. Kerchoff coordinated the interview of affected and unaffected workers at the factory, and summarized his findings: • Strain – those affected were more likely to work overtime frequently and provided the majority of the family income. Many were married with children. • Affected persons tended to deny their difficulties. Kerchoff postulates that such were "less likely to cope successfully under conditions of strain." • Results seemed consistent with a model of
social contagion. Groups of affected persons tended to have strong social ties. Kerchoff linked the rapid rate of contagion with the apparent reasonableness of the bug infestation theory and the credence given to it in accompanying news stories. In 1974, Stahl and Lebedun described an outbreak of mass sociogenic illness in the
data center of a university town in the
United States Midwest. Ten of 39 workers smelling an unconfirmed "mystery gas" were rushed to a hospital with symptoms of dizziness, fainting, nausea and vomiting. They reported that most workers were young women, either putting their husbands through school or supplementing the family income. Those affected were found to have high levels of job dissatisfaction. Those with strong social ties tended to have similar reactions to the supposed gas, which only one unaffected woman reported smelling. No gas was detected in tests of the data center. On the morning of Thursday 7 October 1965, at a girls' school in
Blackburn in England, 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. Moss and McEvedy published their analysis of the event about one year later. Their conclusions follow. In June 1990, thousands were affected by the spread of a supposed illness in a province of
Kosovo in March to June 1990, exclusively affecting
ethnic Albanians, most of whom were young adolescents. Symptoms included headaches, dizziness, impeded respiration, muscle weakness, burning sensations, cramps, retrosternal/chest pain, dry mouth and nausea. After the illness had subsided, a bipartisan Federal Commission released a document, offering the explanation of psychogenic illness. Radovanovic of the Department of Community Medicine and Behavioural Sciences Faculty of Medicine in Safat, Kuwait, reported: In the end, scientists were divided over the scale of the outbreak, whether it fully explains the many different symptoms and the scale to which sociogenic illness affected those involved. Starting around 2009, a spate of apparent poisonings at girls' schools across Afghanistan began to be reported; symptoms included 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 experiencing a mass psychogenic illness. In 2011, a possible outbreak of mass psychogenic illness occurred at Le Roy Junior-Senior High School, in
Le Roy, New York, in which multiple students began having symptoms similar to
Tourette syndrome. Various health professionals ruled out such factors as
Gardasil, drinking water contamination, illegal drugs, carbon monoxide poisoning and various other potential environmental or infectious causes, before diagnosing the students with a
conversion disorder and mass psychogenic illness. In August 2019 the BBC reported that schoolgirls at the
Ketereh national secondary school (SMK Ketereh) in
Kelantan, Malaysia, started screaming, with some claiming to have seen 'a face of pure evil'.
Simon Wessely of
King's College Hospital, London, suggested it was a form of 'collective behaviour'.
Robert Bartholomew, an American medical sociologist and author, said, "It is no coincidence that Kelantan, the most religiously conservative of all Malaysian states, is also the one most prone to outbreaks." This view is supported by Afiq Noor, an academic, who argues that the stricter implementation of
Islamic law in school in states such as Kelantan is linked to the outbreaks. He suggested that the screaming outbreak was caused by the constricted environment. In Malaysian culture, burial sites and trees are common settings for supernatural tales about the spirits of dead infants (
toyol), vampiric ghosts
(pontianak) and vengeful female spirits (
penanggalan). Authorities responded to the Kelantan outbreak by cutting down trees around the school. Episodes of mass hysteria have been frequent in
Nepalese schools, at times even leading to the temporary closure of those schools involved. In 2018, a unique phenomenon of "recurrent epidemic of mass hysteria" was reported from a school of
Pyuthan district of western Nepal after a nine-year-old school girl developed crying and shouting episodes. Other children of the same school became affected in rapid succession, resulting in 47 affected students, 37 females, 10 males, in the same day. Since 2016, similar episodes of mass psychogenic illness have been occurring every year at the same school. This is seen as a rather atypical case of recurrent mass hysteria. In July 2022, reports of up to 15 girls showing unusual symptoms such as screaming, trembling, and banging their heads came up from a government school in
Bageshwar,
Uttarakhand, India. Mass psychological illness has been suggested as a possible cause. In late 2022 and early 2023, thousands of students, mostly girls, in numerous schools in Iran were
initially believed to have been poisoned in various and undetermined manners by unidentified perpetrators and numerous arrests were made. On 29 April 2023, the Iranian Intelligence Ministry released the findings of a comprehensive investigation which concluded that the reported illnesses were not caused by any toxic substances. Instead they were suggested to have been due to a variety of reasons, including exposure to a variety of non-toxic substances, mass hysteria, and malingering. In October 2023, over 100 students from the St. Theresa's Eregi Girls' High School in Musoli, Kenya were hospitalized due to rapid and involuntary arm and leg movement, sometimes accompanied by headaches and vertigo. Routine medical tests revealed nothing unusual, and there were no signs of infectious disease as a cause. Ultimately it was decided that the events were caused by "stress due to upcoming exams" and the incident was determined to be an incident of "hysteria". Due to the determination of collective stress as the cause, medical sociologist
Robert Bartholomew favors the neutral term mass psychogenic illness over mass hysteria, as people respond more favorably to a diagnosis of stress induced symptoms than to a diagnosis of mass hysteria. Bartholomew notes such outbreaks are not unusual in schools in the developing world. This is particularly true in schools in which discipline is tight and accompanied with cultural strain between administrators and students. An outbreak can be preceded by months of such tension, which then results in physical symptoms such as seen in Musoli. Far from faking it, "Under such prolonged stress, the nerves and neurons that send messages to the brain become disrupted, resulting in an array of neurological symptoms such as twitching, shaking, convulsions, and trance-like states." Bartholomew observes that school-stress borne illness such as occurred here have not been uncommon in Africa since the 1960s. Some appear to be due to Christian missionary schools largely ignoring local traditions and mythologies. Instead, such schools impart their own mythologies and culture. This may create overwhelming anxiety due to the students being taught one thing at home, such as ancestor worship, which is then forbidden at a Christian mythology based school. The episode was watched by approximately 4.6 million households. The Pokémon anime went into a four-month hiatus before returning in April 1998 with significant changes to prevent similar incidents. While initial reports suggested thousands of children were affected, research by
Benjamin Radford and sociologist
Robert Bartholomew revealed a more complex picture. Their study, published in the
Southern Medical Journal in 2001, found that while some children experienced genuine
photosensitive epilepsy seizures, the vast majority of the over 12,000 children who reported symptoms exhibited signs more consistent with mass psychogenic illness. A warning about viewing distance and room lighting was added to the beginning of all Japanese television anime shows. The episode "Dennō Senshi Porygon" has never been rebroadcast anywhere in the world and was removed from rotation. The Pokémon incident demonstrates how mass psychogenic illness can occur alongside genuine medical events. The initial physical stimulus of the strobe effect causing real seizures in photosensitive individuals triggered a broader wave of psychogenic symptoms through social contagion, amplified by extensive media coverage and public panic. Seven U.S. intelligence agencies headed by the CIA spent years reviewing thousands of possible cases of Havana syndrome and preparing a report. On 1 March 2023, the
House Intelligence Committee released an unclassified version of the report, titled an "Intelligence Community Assessment".
Politico summarized the results by saying, "The finding undercuts a years-long narrative, propped up by more than a thousand reports from government employees, that a foreign adversary used pulsed electro-magnetic energy waves to sicken Americans." A 2023 academic review article stated that the U.S. intelligence community had concluded that Havana Syndrome is "a socially constructed catch-all category for an array of pre-existing health conditions, responses to environmental factors, and stress reactions that were lumped under a single label".
Children in recent refugee families Refugee children in Sweden have been reported to fall into coma-like states on learning their families will be deported. The condition, known as
resignation syndrome (), is believed to only exist among the refugee population in Sweden, where it has been prevalent since the early part of the 21st century. Commentators state "a degree of psychological contagion" is inherent to the condition, by which young friends and relatives of the affected individual can also come to have the condition. In a 130-page report on the condition, commissioned by the government and published in 2006, a team of psychologists, political scientists and sociologists hypothesized that it was a
culture-bound syndrome, a psychological illness endemic to a specific society. This phenomenon has later been called into question, with children witnessing that they were forced, by their parents, to act in a certain way in order to increase chances of being granted residence permits. As evidenced by medical records, healthcare professionals were aware of this scam, and witnessed parents who actively refused aid for their children, but remained silent. Later,
Sveriges Television, Sweden's national public television broadcaster, were severely critiqued by investigative journalist
Janne Josefsson for failing to uncover the truth. == Society and culture ==