MASS PSYCHOGENIC ILLNESS (MPI)

Mass Psychogenic Illness (MPI)

• No official definition for MPI.

• Closet is the definition for Collective Hysteria, the spontaneous outbreak of atypical thoughts, feelings, or actions in a group or social aggregate. Manifestations may include psychogenic illness, collective hallucinations, and bizarre actions.

Motor Hysteria

• A type of MPI.

• A group of people experience conversion disorder.

• Slow to develop, result of long term group stress.

Anxiety Hysteria

• A type of MPI. 

• A group of people experience psychosomatic illness that does not include a motor component. 

• Sudden onset and rapid recovery, some sort of trigger that sets off the episode. 

Pattern of MPI Outbreaks, Motor Hysteria 

• Occurs in the context of significant social change and societal stressors, with no obvious immediate trigger. 

• Starts with one person experiencing symptoms, which soon spreads to others who have seen or heard the afflicted person. 

• Dies down within days to weeks, with or without intervention. 

Pattern of MPI Outbreaks, Anxiety Hysteria

• Occurs in the context of a single triggering event.

• Starts with a single person or a small group of people, and quickly spreads to others who have heard about the outbreak (direct contact with the afflicted person is not required).

• Outcomes..

  • Sometimes die down when investigations reveal no danger.

  • Sometimes die down with just the passage of time.

  • Sometimes persist, despite evidence showing no external cause.

Historical Changes and Social Factors

Pre 1900s 

• Motor hysteria most common. 

• Related to extremely repressive social roles. 

1900s to Present 

• Anxiety hysteria most common. 

• Related to environmental concerns. 

The presentation of the behavior is influenced by social and cultural variables. 

Current Examples of MPIs

• Havana Syndrome

• Morgellons Disease