Danvers, Massachusetts has a long and, well, unusual history.
Originally known as Salem Village, the mid-sized town (with a population of 26,493 according to a 2010 census) is best known for the Salem witch trials and being the site of one of Massachusetts’ oldest psychiatric hospitals. While rarely appearing in the news otherwise, the town of Danvers got more international publicity that they likely wanted starting in January 2013. That was when about two dozen teenagers at the Essex Agricultural and Technical School in Danvers began reporting bizarre symptoms including “mysterious” hiccups and vocal tics. After the Massachusetts State Health Department ruled out any physical cause for the outbreak, the epidemic gradually subsided over the next few months. Despite speculations that the outbreak may be due to mass psychogenic illness (MPI), the State Health Department has not made any official statement on the cause to date.
While the location of the outbreak seems ironic given Danvers’ legendary history, epidemics of MPI have become increasingly common over the past few years, especially in the United States. According to New Zealand sociologist and skeptic Robert Bartholomew, the Danvers epidemic resembles other cases that occurred. Bartholomew has studied over 6,000 cases of MPI dating back to the 16th century and argues that social media may be playing a strong role in the recent upsurge of cases.
Formerly known as “mass hysteria”, MPI is defined as “the rapid spread of illness signs and symptoms affecting members of a cohesive group, originating from a nervous system disturbance involving excitation, loss or alteration of function, whereby physical complaints that are exhibited unconsciously have no corresponding organic aetiology.” Episodes of MPI have occurred around the world and throughout history with common factors including:
- Symptoms with no known organic basis
- Symptoms with rapid onset and recovery
- Symptoms that are typically transient in nature
- Occurring in a specific group
- Extreme anxiety
- Symptoms are spread by word of mouth or through popular media
- Spreading down the age scale from older to younger victims
- Predominantly female victims
Symptoms linked to MPI outbreaks can include nausea, headaches, abdominal cramps or pain, fainting, chest pain, vomiting, diarrhea, and anxiety attacks. According to British psychologist, Simon Wessely, MPI can manifest itself as either “mass anxiety hysteria” with episodes of acute anxiety (primarily in schoolchildren), or as “mass motor hysteria” involving abnormal motor behaviour.
To read more, check out my new Psychology Today post.