Mass psychogenic illness and the social network: is it changing the pattern of outbreaks?
Authors: Robert E Bartholomew, Simon Wessely, G James Rubin
Journal: Journal of the Royal Society of Medicine (2012)

In October 2011, several adolescent girls at a high school in the town of Leroy, New York (pop. 7641), spontaneously developed facial tics, muscle twitching and garbled speech. By early January 2012, it was revealed that the New York State Health Department had diagnosed the students (by now, 14 women and 1 man) with conversion disorder. News of the ‘mass hysteria’ diagnosis has been vigorously challenged by parents who have formed their own advocacy group. Several victims have appeared on national television to denounce the diagnosis; celebrities have tweeted support for the students and expressed scepticism over its psychogenic origin, while some physicians have publicly suggested alternative explanations. This case has dominated headlines in the USA and continues to generate anxiety and controversy. A common folk theory attributes the symptoms to exposure from a nearby toxic dump, prompting environmental activist Erin Brockovich to challenge the diagnosis and open an independent investigation to determine the ‘real’ cause.

There is increasing recognition that mass psychogenic illness (MPI) is underappreciated, under-reported and poses a significant health and social problem.1,2 The financial impact includes the cost of testing to eliminate environmental and organic causes, and the response by emergency services and public health specialists who expend precious time and resources. Schools and factories may temporarily close, resulting in lost production and income, and educational outcomes may be disrupted. When the diagnosis is challenged, students and workers may refuse to enter the premises and erode public confidence in the health system. Ongoing anxiety over the possible existence of a toxic agent may contribute to a variety of stress-related illnesses. The financial burden can be enormous. In 1999, an MPI outbreak in the Belgian school system over the suspected contamination of Coca-Cola products prompted a recall costing the company an estimated US$250 million.3 In 2007, a fainting episode among a group of anxious Australian schoolgirls who had received inoculations for the human papillomavirus, resulted in AU$1 billion being wiped from the stock market value of the corporation producing the Gardasil vaccine.4 Disputed diagnoses surrounding vaccination programmes have resulted in social protests and parents refusing to inoculate their children, placing them at unnecessary risk for preventable diseases.5 Finally, victims can get trapped in wider social arguments and conflicts, especially when the veracity of their symptoms is challenged, impeding their recovery.

There are two main types of MPI. The most common in Western countries (anxiety hysteria) is triggered by extreme, sudden stress within a close-knit group. It is usually triggered by a foul or unfamiliar odour that is perceived to be harmful. Symptoms are transient, benign and typically include dizziness, headache, fainting and over-breathing. Most victims recover within 24 hours and there is an absence of pre-existing tension within the group. A second type (motor hysteria) arises from long-term anxiety and features motor agitation. Common symptoms include twitching, shaking, trouble walking, uncontrollable laughing and weeping, communication difficulties and trance states. Symptoms appear slowly over weeks or months under exposure to longstanding stress, and typically take weeks or months to subside, after the stress has been reduced or eliminated.6