Mass Psychosis: Understanding Its Causes And Mental Health Symptoms

Mass psychosis, also referred to as mass psychogenic illness (MPI), mass hysteria, or mass sociogenic illness (MSI), is generally defined as a psychological and social phenomenon in which individuals experience severe collective distress caused by delusions or false beliefs. These irrational behaviors or beliefs often spread rapidly within the group, frequently creating mass outbreaks of fear and anxiety and leading to physical symptoms.

The potential reasons for mass psychosis are varied and often reflective of cultural factors, interactions between individuals, and social constructs. This complex phenomenon has been observed throughout history in varying contexts, and its consequences can range from mild and minor to severe and widespread. However, there are ways to counter mass psychosis and cultivate better mental health in the community and for individuals. In general, these include public health education and awareness efforts and increased availability of mental health services.

What is mass psychosis?

Mass psychosis can describe a psychological phenomenon in which a cohesive group begins to exhibit similar symptoms that are typically associated with mental or physical illness. Groups experiencing mass psychosis may have extreme stress or fear related to a perceived threat. This threat is often exaggerated or nonexistent. They may believe that something specific led to their symptoms, although there is typically no identifiable medical cause, and their behavior when affected by mass psychosis is usually out of character. Mass psychosis, which is frequently referred to by other names, is often studied as part of social psychiatry.

Mass psychosis, mass hysteria, and mass psychogenic illness

When people talk about mass psychosis, mass hysteria, and mass psychogenic illness (MPI), they are usually referring to the same phenomenon. Collective panic can lead to various physical complaints or illness symptoms with no identifiable physical cause. However, just because there is no identifiable medical, physical, or environmental cause does not mean these unexplained symptoms are imagined. 

Stressful situations and mental distress can affect the nervous system and lead to various illness signs, which can be exhibited unconsciously. Common examples include getting a headache when stressed or a stomachache when nervous. Consider the experience of stage fright as well. In mass psychosis, this phenomenon of mental distress leading to physical symptoms can happen on a larger scale.

Types of MPI or mass psychogenic illness

The British psychiatrist Simon Wessely labeled two types of MPI in 1987. Although updated research may be beneficial, Wessely’s contributions are still frequently referenced in discussions of MPI today.

Mass anxiety hysteria

This type of mass psychosis can be characterized by shorter, more acute episodes of anxiety without prior distress. According to Wessely, mass anxiety hysteria:

• Is often observed in schoolchildren
• Is confined to group interaction 
• Spreads rapidly via visual stimuli

In this type of MPI, positive outcomes may be achieved by separating individuals within the group.

Mass motor hysteria

Mass motor hysteria is typically characterized by a slower accumulation of repressed anxiety with prior distress. It can occur in any age group. Dysfunction in personalities and environments is normally identified as a source of disruption, and the spread tends to be gradual in nature. Mass motor hysteria often features abnormalities in motor behavior, like tremors and unusual symptoms of dissociation and panic. Effective treatment for mass motor hysteria generally involves addressing and managing underlying stressors.

Wessely's models are those most commonly referenced when examining cases of MPI. However, other scientists posit that features of the two types often overlap, and one comprehensive definition might be more suitable.

How mass psychogenic illness begins and spreads

Mass psychogenic illness (MPI) typically begins with environmental factors–for example, a bad smell. In most cases, one person begins to feel sick, and suddenly, the others in the group begin to feel sick as well. It may be important to note that the first individual who exhibits symptoms may be legitimately sick for a reason separate from the environmental stimulus. 

Symptoms typically spread due to a heightened sense of worry and anxiety among the group. Factors like rumors and news reports about the incident, as well as the sight of ambulances and emergency services workers, can heighten stress and contribute to the spread of symptoms as well. Even hearing that someone you know is experiencing symptoms or seeing someone get sick may lead you to develop similar symptoms. The rapid onset of such outbreaks, as well as similarities between reported illnesses and reported symptoms affecting members of a group, can point to the probability of MPI or mass hysteria-related phenomena, particularly if a clear physical cause cannot be identified.

Signs of mass psychosis: Common symptoms reported during outbreaks

Mass psychosis can manifest in various ways. Outbreaks often follow a sensory experience like an unpleasant smell, a suspicious-looking object or substance, an unidentified sound, or another form of stimuli that may create fears of exposure to environmental danger. 

Stimuli leading to mass psychosis may contribute to the "nocebo effect," in which an individual develops symptoms or physical complaints because they expect to do so. The nocebo effect can be considered the opposite of the placebo effect, in which an individual experiences symptom relief because they expect a treatment to work. In both cases, outcomes aren't necessarily based on reality.

Who is most commonly affected and why

It’s thought that children, adolescents, females, and groups under stress tend to be most commonly affected by MPI, with adolescent girls perhaps constituting the most reported demographic. Common settings in which MPI has taken place during its long history include schools, factories, convents, towns, and villages. MPI has taken place in various historical periods, albeit by different names, and may be more common than many realize. 

Contributors to MPI

There are many potential sociological contributors that may explain why large groups of individuals can experience shared psychogenic symptoms with no identifiable physical cause. Social psychiatry notes that these are real physical symptoms, not imagined ones, but that their root causes are not clear and seem to be linked to collective panic. Examples of potential contributors to unexplained symptoms of MPI include, but aren't limited to, those listed below.

Echo chambers and confirmation bias

Groups may isolate themselves from differing perspectives and only consume information that reinforces their existing beliefs. Echo chambers and confirmation biases often lead to distorted perceptions of reality.

Moral panic leading to mass psychosis

Moral panic can be described as sudden and widespread fear or concern over an issue that is perceived to threaten societal values or norms. Such panic often leads to collective overreactions or disproportionate responses.

Scapegoating and group blame 

Blaming specific individuals or groups for perceived societal problems or injustices can cultivate discrimination, persecution, or violence within a group. Scapegoating may contribute to MPI in some circumstances.

Cultural or societal paranoia that causes mass psychogenic illness

The pervasive fear or distrust of external forces, such as government institutions, foreign powers, or minority groups, can sometimes lead to irrational behaviors. It can also impact society on a larger scale when hurtful laws or policies are created due to that paranoia.

Cultural or religious mass movements

These can refer to instances where large groups adopt extreme or irrational beliefs or behaviors under the influence of charismatic leaders or societal pressures. Like cultural or societal paranoia, mass movements can impact society on a larger scale when laws and policies are enacted at the expense of others because of irrational beliefs.

Social contagion of beliefs or behaviors

This generally refers to the rapid spread of particular beliefs or behaviors through social networks. This often occurs without critical evaluation or examination of evidence.

Loss of critical thinking and individuality

Individuals within a group may abandon rational thought and uncritically accept the beliefs or behaviors of the collective. This may lead to a loss of personal autonomy.

It can be relevant to note that not all instances of collective belief or behavior are indicative of mass psychosis. Sometimes, shared beliefs can emerge from valid sources or experiences. 

Mass psychosis events in history

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V) doesn't officially recognize mass psychogenic illness as a type of mental health disorder. However, scientists have researched the condition throughout history. 

There are many well-known examples of events where collective fear, misinformation, and societal pressures led to irrational beliefs and behaviors among groups. Here are a few global examples of mass hysteria from ancient to modern times.

The dancing plague of 1518

The dancing plague occurred in the Middle Ages when a woman began to dance in the streets of a village in Germany. She danced uncontrollably for a week, and within two months, 400 people were reportedly experiencing the same symptom. The reasons for the plague remain unknown, but experts posit that the villagers could have been experiencing stress-induced delusions caused by religious fears associated with St. Vitus (some at the time believed he cursed the impious with uncontrollable dancing), disease, and famine. Some others believe the dancing may have resulted from delusions caused by ergot food poisoning. 

The Salem witch trials (1600s)

Historians believe the Salem witch trials began when doctors and religious leaders in the village of Salem proclaimed that two young girls experienced convulsions and other symptoms because they had been "bewitched." When other girls in the town began experiencing the same symptoms, village leaders began to single out scapegoats (typically marginalized or unpopular individuals in the community, most of whom were women) and label them as the witches responsible for the mass illness. The accusations continued, and cases of witchcraft began emerging around the world, creating epidemic hysteria and fear that led to the false allegations and deaths of many innocent people. 

The War of the Worlds Panic (1938)

When Orson Welles’s realistic radio adaptation of The War of the Worlds (penned by H.G. Wells) aired, it caused mass hysteria and panic among listeners who believed they were under attack by aliens. With radio being relatively new at that time, it wasn’t clear to many that they were listening to a fictional show.

The Red Scare (1950s)

During the Cold War era, the widespread fear of communism in the US led to the persecution of suspected communists. Individuals in various industries were blacklisted as a result.

The Tanganyika laughing epidemic (1962)

The laughing epidemic began with a few people in a girls' school in Tanganyika (now Tanzania), eventually spreading to what experts estimate to be roughly 1,000 people across several communities. Symptoms included chronic laughing and crying lasting from a few hours to a couple of weeks, sometimes accompanied by aimless running and violent outbursts. The exact cause of the laughing epidemic is unknown, but believed to be related to heightened, chronic stress associated with conditions in the school and societal unrest at the time. 

The Satanic Panic (1980s-1990s)

A moral panic emerged in the US during the 1980s and 1990s in which people believed that there was a widespread conspiracy of satanic rituals and abuse. This led to false accusations, legal convictions, and media hysteria. 

If you or a loved one is experiencing abuse, contact the Domestic Violence Hotline at 1-800-799-SAFE (7233). Support is available 24/7.

Consequences of mass psychosis or mass hysteria

Mass psychosis can have far-reaching consequences on individuals and societies. For example, individuals experiencing MPI often develop psychological and physical distress stemming from delusions. This can lead to irrational behaviors and poor decision-making. MPI can contribute to widespread economic, sociological, and political unrest on a larger scale. The polarization and division in society sometimes resulting from MPI can create an erosion of trust in essential institutions. 

Addressing and preventing mass psychosis: Clinical response and public health guidance

Addressing and preventing mass psychosis typically requires a multi-faceted approach involving the following:

• Education and awareness efforts to encourage critical thinking, media literacy, and fact-checking to help individuals question assumptions, seek evidence, and differentiate between credible information and misinformation
• Availability of mental health services and resources to help individuals cope with the fear and anxiety that may contribute to mass psychosis
• Open dialogue and communication within communities to address concerns, clarify misinformation, and promote rational discussion
• Fact-checking and verifying information before dissemination to avoid the spread of false beliefs
• Accountability from media outlets for responsible reporting and fact-based journalism
• Community support and solidarity to combat feelings of isolation, fear, and paranoia that can contribute to mass psychosis
• Empathy and understanding between individuals experiencing fear or anxiety during times of uncertainty or crisis
• Early intervention through recognition, support services, and awareness of targeted messaging to prevent the escalation of irrational beliefs and behaviors

It can be important for healthcare providers, such as family physicians, to rule out medical emergencies in those appearing to experience mass psychosis. Examining the environment for potential causes of symptoms can also be vital. When such outbreaks happen, public health officials may need to take steps to limit the spread of rumors, provide consistent updates, and avoid sensationalizing the situation.

How to seek mental health support for mass psychosis

Because fear and anxiety can fuel mass psychosis, mental health support tends to be a critical part of preventing it. If you or someone you love is experiencing symptoms of mass psychogenic disorder or another type of conversion disorder, seeking guidance from a mental health professional is recommended. Various therapeutic approaches can aid affected individuals in reducing stress.

Despite the importance of mental health care, some people who need therapy encounter barriers to treatment when they attempt to seek professional help. For example, scheduling or transportation issues might make attending sessions difficult. Some may feel uncomfortable talking to a therapist because of the stigmas that can be associated with mental health treatment. Still others might assume they cannot afford therapy.

Telehealth services from mental health professionals

The rise in popularity of telehealth services has provided opportunities for individuals to overcome the obstacles discussed above and receive therapy that is as effective as traditional treatment. Research suggests that online and in-person therapy typically produce the same outcomes.

Online therapy platforms usually offer flexible scheduling options and a broader pool of mental health professionals from which to choose. Additionally, if the relationship between the therapist and client isn't productive, individuals may change therapists at any time with just a few clicks.