Mass psychogenic illness

set of medical symptoms affecting U.S. and Canada government personnel

feeling of fear spread among a large number of people that some evil threatens the well-being of society

physical illness or symptoms caused by serious emotional stress

medieval social phenomena

shared psychosis, a psychiatric syndrome in which symptoms of a delusional belief are transmitted from one individual to another

phenomenon that transmits collective illusions of threats, whether real or imaginary, through a population in society as a result of rumors and fear

1962 outbreak of mass hysteria

abuse in the context of occult rituals

Morgellons () is the informal name of a self-diagnosed, scientifically unsubstantiated skin condition in which individuals have sores that they believe contain fibrous material. Morgellons is not well understood, but the general medical consensus is that it is a form of delusional parasitosis, on the psychiatric spectrum. The sores are typically the result of compulsive scratching, and the fibers, when analysed, are consistently found to have originated from cotton and other textiles.

spontaneous spread of emotions among a group

genital-related neurosis, in which an individual has an overpowering belief that one’s genitalia are retracting and will disappear, despite the lack of any true longstanding changes to the genitals

form of public humiliation and torture used by the Chinese Communist Party in the Mao era

spread of illness symptoms through a population where there is no viral or bacterial agent responsible for contagion

form of addiction that involves a compulsion to engage in a rewarding non-drug-related behavior despite any negative consequences to the person's physical, mental, social or financial well-being

thumb|Lycosa tarantula carrying her offspring

alleged capture of an extraterrestrial being in Brazil in 1996

game and Internet meme

Popobawa, also Popo Bawa, is the name of an evil spirit or shetani, which is believed by residents of Zanzibar to have first appeared on the Tanzanian island of Pemba. In 1995, it was the focus of a major outbreak of mass hysteria or panic which spread from Pemba to Unguja, the main island of the Zanzibar Archipelago, and across to Dar es Salaam and other urban centres on the East African coast.

1841 collection of historic anecdotes about human follies by Charles Mackay

behavior, emotions, or conditions spreading spontaneously through a group or network

Homohysteria is the fear of being thought homosexual because of behavior that is typically considered gender atypical. Homohysteria can exist in cultures where it is understood that people are and can be homosexual, even if closeted, and that homosexuality is perceived as less desirable than heterosexuality. This combination leads to men fearing others will think they are gay if they do not fit male gender stereotypes. Not fitting into gender stereotypes (gender atypicality) has historically been associated with gay men, with the trials of Oscar Wilde furthering this belief in Britain and else

effect in which a group exhibits physical symptoms due to a psychological cause