When a large number of people may come to believe obviously false and potentially distressing things based purely on hearsay, these beliefs are not considered to be clinical delusions by the psychiatric profession, and are instead labelled as mass hysteria. As with most psychological disorders, the extent and type of delusion varies, but the non-dominant persons delusional symptoms usually resemble those of the inducer. Prior to therapeutic interventions, the inducer typically does not realize that they are causing harm, but instead believe they are helping the second person to become aware of vital or otherwise notable information. Type of delusions
Psychology Today magazine defines delusions as "fixed beliefs that do not change, even when a person is presented with conflicting evidence." Types of delusion include:
Bizarre delusions
Those which are clearly implausible and not understood by peers within the same culture, even those with psychological disorders; for example, if one thought that all of their organs had been taken out and replaced by someone elses while they were asleep without leaving any scar and without their waking up. It would be impossible to survive such a procedure, and even surgery involving transplantation of multiple organs would leave the person with severe pain, visible scars, etc. Non-bizarre delusions
Common among those with personality disorders and are understood by people within the same culture.
As no drugs or poison were found in her system, her death remains a mystery. Fulfilling their pact, June proceeded to live an otherwise-normal life. The Burari Deaths, wherein a family of 11 members was found hanging in their home in Delhi, was ruled as a case of "Shared Psychosis," led by the youngest son of the matriarch. In popular culture
In Folie à Deux (The X-Files) Season 5, Episode 19 (1998), Mulder is taken hostage by an employee who believes his boss is turning his coworkers into zombies. Bug (2006) is a film that depicts a couple with a shared delusion that aphids are living under their skin. In Season 2, Episode 3 of Criminal Minds, "The Perfect Storm" (2006), Dr. Reid mentions that the rapists had this condition. Folie à Deux (2008) is an album by American rock band Fall Out Boy
The independent film Apart (2011) depicts two lovers affected and diagnosed with induced delusional disorder, trying to uncover a mysterious and tragic past they share. In a 2011 interview, director Aaron Rottinghaus stated the film was based on research from actual case studies. Nine Perfect Strangers shows a couple who lost one of their two children. The couple and the surviving child have shared hallucinations of the dead child.