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Evidence Mounts that Mass Suggestion Caused "Havana Syndrome"

Studies suggest that a 'mystery illness' in Cuba was caused by social contagion.

Key points

  • Classified reports conclude that psychogenic illness played a major role in "Havana Syndrome."
  • Recent actions by Defense Department are tantamount to a global experiment in mass suggestion.
  • Myths about ‘Havana Syndrome’ continue to circulate

The contents of two U.S. government investigations into the origins of the 'Havana Syndrome' both found that mass psychogenic illness was likely a major driver of the outbreak. The condition was first reported in late 2017 by U.S. diplomats in Cuba and includes fatigue, memory problems, nausea, ear pain, dizziness, confusion, headaches, trouble sleeping, and sensations of pressure. While it is commonly reported that brain damage is part of the condition, such claims are not supported by the data. As R. Douglas Fields of the National Institutes of Health observes, "There is no evidence of any pathology…when you look at the data, there's no coherent syndrome, no pattern" (Hamilton 2019).

Source: DedMityay/Shutterstock

The first report, Acoustic Signals and Physiological Effects on U.S. Diplomats in Cuba was produced by a group of specialist scientists who issue advice on matters of national security. Their findings were publicly released in September 2021 under the Freedom of Information Act. The report deemed that claims of microwave radiation involving the ‘Frey Effect’ to be far-fetched. This effect involves the production of barely audible clicking sounds. However, the sounds heard by the diplomats in Cuba did not resemble the Frey Effect. Furthermore, over a dozen recordings were made during 'attacks.' Analysis revealed they were identified as the sounds of crickets and cicadas. One of the first scientists to identify how the Frey Effect works, bioengineering professor Ken Foster at the University of Pennsylvania, said, “the Frey Effect is real, but it has nothing to do with the Havana syndrome.” Foster says it is highly unlikely the effect could ever be weaponized (Foster 2021). The findings of a second report, produced by the FBI's Behavioral Analysis Unit, were recently leaked to Pulitzer Prize-winning journalist Adam Entous. It concluded that the victims were experiencing “mass psychogenic illness.”

A Global Experiment in Mass Psychology

In 2018, after ‘attacks’ were reported by several American diplomats stationed in China, the State Department cautioned that its foreign corps should be vigilant for attacks at other locations. To date, ‘attacks’ have been reported on U.S. officials in over a dozen countries including China, Australia, the United Kingdom, Uzbekistan, Colombia, Germany, Austria, Vietnam, and near the White House. The spread of 'Havana Syndrome' around the world is unsurprising given that the symptoms are so vague and common. By warning diplomats and intelligence officers to be on the lookout for "anomalous health incidents" that may or may not be accompanied by strange sounds, the U.S. government has created a global experiment in the nocebo effect whereby negative expectations produce negative symptoms. Think of it as the opposite of the placebo effect. To complicate matters, in September, Defense Secretary Lloyd Austin sent letters to nearly 2.9 million military personnel, civilian officials, and contractors, warning them to be vigilant for any unusual health incidents. It stated, in part, “Over the course of the last several years, and predominantly overseas, some DOD (Department of Defense) personnel have reported a series of sudden and troubling sensory events such as sounds, pressure, or heat concurrently or immediately preceding the sudden onset of symptoms such as headaches, pain, nausea, or disequilibrium (unsteadiness or vertigo)." That nearly 3 million people have been told to be alert for anomalous health incidents is a recipe for a forthcoming cluster of anomalous health incidents as subjects redefine a plethora of conditions under a new label, ‘Havana Syndrome.’

The Myth of Brain Damage

One of the reasons for the spread of the belief that ‘Havana Syndrome’ is caused by a secret weapon is the continued reporting of misinformation. Perhaps the biggest myth is that many victims suffered brain damage. This was popularized after the publication of a 2019 study in the Journal of the American Medical Association. The study found brain anomalies in the patients. However, this is not the same as brain damage, but it was widely reported as such. In fact, the same study admitted that the anomalies were not so significant that they could not rule out the possibility they were caused by individual variation (Ragini et al., 2019). Furthermore, similar anomalies have been elicited from exposure to long-term stress, which is what embassy personnel were experiencing after rumors spread that they were being targeted for sonic attacks using a secret weapon. Also, 12 of the patients had histories of concussions, compared to zero in a healthy control group. This alone could explain the differences between the two groups (Baloh & Bartholomew 2020).

‘Havana Syndrome’ is the most recent in a long history of fears about new technologies prompting health complaints. It won't be the last.


Acoustic Signals and Physiological Effects on U.S. Diplomats in Cuba, November 2018. Declassified U.S. Government study.

Austin, Lloyd (2021). “Anomalous Health Incident.” Memorandum for All Department of Defense Employees, September 15.

Bartholomew, Robert, and Baloh, Robert (2019). “Challenging the diagnosis of ‘Havana Syndrome’ as a novel clinical entity.” Journal of the Royal Society of Medicine 113(1):7-11.

Bartholomew, Robert, and Perez, Dionisio F. Zaldivar (2018). “Chasing ghosts in Cuba: Is mass psychogenic illness masquerading as an acoustical Aattack?” International Journal of Social Psychiatry 64(5):413-416.

Baloh, Robert, and Bartholomew, Robert (2020). Havana Syndrome. Cham, Switzerland: Copernicus Books.

Cortex Editorial Board (2018). Responsibility of neuropsychologists: the case of the ‘sonic attack’. Cortex 108:A1–2.

Della Sala, Sergio, Cubelli, Robert (2018). Alleged ‘sonic attack’ supported by poor neuropsychology. Cortex 2018;103:387–8.

Entous, Adam (2021). “Are U.S. officials under silent attack?” The New Yorker, May 24:

Foster, Ken (2021). Personal communication, October 2.

Hamilton, Jon (2019). “Brain scans find differences but no injury in U.S. diplomats who fell ill in Cuba.” All Things Considered, National Public Radio (Washington DC), July 23.

Ragini V, Swanson, RL, Parker D, Ismail A, Shinohara RT, Alappatt JA, et al. (2019).“Neuroimaging findings in US government personnel with possible exposure to directional phenomena in Havana, Cuba.” JAMA 322(4):336-47 (July 23).

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