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Does "Mass Formation Psychosis" Really Exist?

Psychiatric terms shouldn't be misused to label our ideological opponents.

Key points

  • "Mass formation psychosis" is not an appropriate psychiatric term or a clinical diagnosis to describe "groupthink."
  • Terms like "mass delusion" and "mass psychosis" are being used inappropriately as pejoratives to denigrate our ideological opponents.
  • Psychiatric terminology should not be used to advance political agendas.
U.S. National Archives & DVIDS/Public Domain
Source: U.S. National Archives & DVIDS/Public Domain

"Mass psychosis," "mass delusion," "mass formation psychosis," and "mass delusional psychosis" are terms being thrown around a lot lately to describe our ideological opposites. This is a pejorative and inappropriate use of psychiatric terminology as I explained in my previous post. Here are some additional thoughts that came up during a recent discussion on this topic.1

Does something like “shared delusion” or “mass psychosis” exist? And are there true cases of it that have been documented?

Psychiatry has always been careful not to label culturally sanctioned beliefs—like religious beliefs—as delusions. Accordingly, delusions are defined as fixed and false beliefs that are idiosyncratic to the believer and not shared within a culture or subculture. That said, it has long been recognized that delusions are sometimes shared between people. This traditionally occurs within a dyad like a parent and a child where one person is delusional and the other is impressionable—this has been referred to as “folie à deux” or the “insanity of two.” Shared psychosis, or shared delusion, has sometimes been applied to a handful of people sharing a delusional belief, but the term was never meant to describe what the journalist Charles Mackay called “Popular Delusions and The Madness of Crowds” back in 1841. Groupthink, whether it occurs in religion or politics, is not a matter of delusional thinking, psychosis, or mental illness and it’s a disservice to those who have mental illness to claim it is. It’s also a disservice to ourselves because it distracts us from the real social forces that lead to widespread false belief.

The physician Robert Malone claimed that getting vaccinated, or taking other COVID precautions, can be explained by "mass formation psychosis." Why isn't that correct?

A delusion is a belief, not a behavior. The question we should ask is what beliefs are driving whether people get vaccinated or not? If they’re getting vaccinated because they believe that the advice of scientists and public health epidemiologists is sound, or that following evidence from research studies supporting the efficacy of vaccines or wearing masks makes sense, that’s obviously not a delusion. But not believing scientists, or Dr. Fauci and the CDC, or research studies and instead following the guidance of Robert Malone isn’t a delusion either. The end result may be a fixed, false belief, but that’s not a product of mental illness, it’s a product of pervasive mistrust in authoritative sources of information resulting in vulnerability to misinformation and disinformation that’s out there in the world.2 That reflects a kind of social ill of society, not the mental illness of individuals en masse.

Mass delusional thinking or mass psychosis are terms that have been used on both ends of the political spectrum. Why are these constructs so easily co-opted and applied?

What’s going on right now is a kind of tit-for-tat. Conservatives and anti-vaxxers like Robert Malone are claiming that following scientific evidence about the pandemic and supporting vaccine mandates can be explained by “mass formation psychosis.” Meanwhile, articles in a liberal magazine like The Atlantic have been using terms like “mass delusion” and “mass psychosis” to describe the kind of conspiracy theory beliefs that motivated the Capitol insurrectionists. This is pejorative name-calling of our ideological opposites on both sides of the political fence. It’s not a proper or responsible use of psychiatric terminology. It’s also the equivalent of Hillary Clinton’s “basket of deplorables” gaffe—calling our ideological opposites “crazy” just alienates people further and worsens political polarization rather than getting us closer to the kind of collaborative work we need to do to get us through the pandemic as a nation and as a world.

How can we distinguish between extreme ideological beliefs and delusions?

Most things in nature can be conceptualized on a continuum. We recognize that there’s a color called “red,” but the reality is that “red” represents a spectrum or range of wavelength intensity and sorting out where red ends and orange begins is “fuzzy.” It’s the same when we talk about delusions and what psychiatry sometimes calls “overvalued beliefs” and what some have recently called “extreme overvalued beliefs.”3 It’s often a matter of degree, where the degree depends on cognitive dimensions like “conviction” (how strongly we believe something) and preoccupation (how much time we spend thinking about it).

Beyond the continuum, the categorical guidelines to separate delusions from non-delusions are fairly straightforward. Delusions are fixed and false, but for the most part, aren’t shared beliefs. They’re idiosyncratic and self-referential, meaning they’re often about the believer rather than beliefs about the world. It’s relatively easy to find other people who share the belief that there will be a Second Coming of the Messiah, but it isn’t nearly as easy to find people who agree that you’re the Messiah. Delusions also aren’t typically based on information or misinformation that one encounters in the world. If someone believes something because they “did their research” and found “evidence” somewhere on the internet, that’s not what psychiatrists are talking about when we talk about delusions.

The response to Malone's statement is that "mass formation psychosis" just doesn't exist. Is this a helpful response? People can see online that there have been studies on phenomena that are similar to what he's talking about.

“Mass formation psychosis” doesn’t exist as a recognized psychiatric diagnosis so that it’s a misuse—and arguably a deliberate misuse—of psychiatric terminology. But then Malone isn't really claiming that it’s a psychiatric diagnosis and “mass formation psychosis” isn’t even his idea—he borrowed the concept from a Belgian psychologist named Matthias Desmet who uses the term "mass formation" without referring to "psychosis" and psychiatrist Mark MacDonald who prefers the phrase “mass delusional psychosis." Physicians and mental health professionals should know better than to toss such stigmatizing terms around so casually, but then we also had psychiatrists try to tell the American public that Donald Trump was mentally unfit to be President because he had a psychiatric disorder. So unfortunately, we have mental health professionals on both sides of the political fence using psychiatric terms irresponsibly to advance political views.

When psychiatrists and psychologists say that "mass formation psychosis" doesn't exist, we mean that what Malone, Desmet, and MacDonald are trying to describe isn't psychosis or evidence of mental illness. But despite their poor choice of words, they're not really claiming that people who support vaccination and vaccine mandates are actually delusional or mentally ill. Instead, they’re using “psychosis” as a pejorative to say that people are ill-informed because they’re victims of fear that makes them vulnerable to authoritarianism.§ But meanwhile, MacDonald is out there promoting ivermectin to treat COVID-19 and acting as an advisor to Ronald DeSantis—the governor of a state near the very top of per capita COVID-19 cases here in the US. Desmet and MacDonald are right that fear can lead us to over-estimate risk and take excessive precautions—like what we’ve been putting up with when we get on an airplane since 9/11—but there have been over 860,000 deaths in the US from COVID-19 since the start of the pandemic and an average of 1600 deaths a day this week during the peak of Omicron.

Based on these realities, is concern about getting COVID-19 irrational or smart? That’s the wrong question to ask. The right question is how to best prevent morbidity and mortality from COVID-19 and how to protect the most vulnerable people in our country—like our parents and grandparents who are most at risk. When we’re dealing with a global pandemic, the evidence-based answer is herd immunity, which is best and most safely achieved through vaccination and behavioral measures like masking and social distancing to prevent spread. It would be great if we could achieve that without mandates, but here we are.

Although we Americans take pride in our individualism and like to talk about “not giving up our freedoms,” we could really use more altruism for the greater good right now. There’s nothing delusional or psychotic about that.

To read more on this topic:


1. This post was adapted from an interview I did with Shayla Love for her VICE magazine article: Love S. Protecting yourself from COVID isn’t a sign of mental illness. VICE; January 20, 2022.

2. Pierre JM. Mistrust and misinformation: A two component, socio-epistemic model of belief in conspiracy theories. Journal of Social and Political Psychology 2020; 8:617-641.

3. Pierre JM. Forensic psychiatry versus the variety of delusion-like beliefs. Journal of the American Academy of Psychiatry and the Law 2020; 48:327-334.

§. Malone and Desmit's claim that "mass formation" is a telltale feature of emerging authoritarian movements is something that the late Hannah Arendt, one of the most respected political scholars of authoritarianism, wrote about extensively.

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