Havana syndrome affected Cuba-based diplomats


A new interdisciplinary study on the “Havana Syndrome” led by Dr. Alon Friedman M.D. of Ben-Gurion University of the Negev (BGU) in Israel and Dalhousie University Brain Repair Center in Nova Scotia, Canada, points to overexposure to pesticides as a likely cause for neurological symptoms among Canadian diplomats residing in Havana, Cuba in 2016. This is the first study of its kind focused on Canadian diplomats.

The “Havana Syndrome” was the name given to the symptoms initially believed to be acoustic attacks on U.S. and Canadian embassy staff, first reported in Cuba.

Beginning in August 2017, reports surfaced that American and Canadian diplomatic personnel in Cuba had suffered a variety of health problems including headaches and loss of balance, as well as sleep, concentration, and memory difficulties.

To ensure Dr. Friedman and his team’s findings are properly interpreted and understood, Dr. Friedman elected to discuss his research in advance of peer-reviewed publication with the Canadian Broadcasting Service which obtained a draft report to the Canadian government, leaked by an unknown source.

The research will be presented at Breaking the Barriers of Brain Science Symposium in New York on Sunday, October 27.

The study details the nature of the injury, specifies the brain regions involved, including the blood-brain barrier and suggests a possible cause in the form of “cholinesterase inhibitors,” with “organophosphorus insecticides” being a likely source.

Cholinesterase (ChE) is one of the key enzymes required for the proper functioning of the nervous systems of humans, invertebrates and insects.

In total, there were 26 Canadian participants: 23 Canadian diplomats and their family members who lived in Havana were included in the study, as well as individuals who didn’t live in Cuba.

“We were also able to test several of the subjects before and after they returned from Cuba,” Dr. Friedman says.

“Our team saw changes in the brain that definitely occurred during the time they were in Havana.”

Dr. Friedman and his team attribute the study’s findings to multidisciplinary and quantitative research methods, in particular, their use of new brain imaging tools including advanced Magnetic Resonance Imaging (MRI) techniques and magnetoencephalography.

“We followed the science, and with each discovery we asked ourselves more questions,” said Dr. Friedman. “Pinpointing the exact location of where the brain was injured was an important factor that helped lead us to perform specific biochemical and toxicological blood tests and reach the conclusion that the most likely cause of the injury was repeated exposure to neurotoxins.”

This shows the US embassy in Cuba

In total, there were 26 Canadian participants: 23 Canadian diplomats and their family members who lived in Havana were included in the study, as well as individuals who didn’t live in Cuba. The image is credited to U.S. Embassy in Cuba.

The researchers involved also represented a wide range of disciplines, including neuroscience, neurology, psychiatry, audio-vestibular, ophthalmology, toxicology and even veterinary medicine.

“The study validates the need for us to continue to learn more about the use of pesticides and other toxins,” said Dr. Friedman. “It is a global health issue that reminds us how much we still have to learn about the impact that toxins have on our health.”

Funding: The study was requested and funded by Global Affairs Canada, who partnered with the Nova Scotia Health Authority. Also participating in the study were Dr. Friedman’s group at BGU and Dr. Shamir from The Koret School of Veterinary Medicine at Hebrew University.

Several psychiatric conditions exhibit a pattern of communicability, including mass psychogenic illness, folie à deux or folie à famille and epidemic koro (Ventriglio & Bhugra, 2017).

While each is widely viewed as being triggered by psychosocial stress which affects vulnerable individuals, it is essential to view stress ‘as a matter of definition in a specific sociocultural context rather than as an objective given from which predictions can be made’ (Lee & Ackerman, 1980, p. 79).

Therefore, when investigating outbreaks of psychogenic illness and kindred phenomena, it is important to focus on the social context underpinning the beliefs, instead of the symptoms per se. A recent, relevant illustration of this occurred in Cuba.

Between November 2016 and October 2017, a mysterious illness was recorded among 24 diplomatic staff working at the United States Embassy in Havana.

Victims reported hearing a high-pitched sound within an hour of their symptoms which included headaches, lightheadedness, nausea, fatigue, tinnitus, difficulty concentrating, memory problems, confusion, insomnia, hearing loss, vertigo, nosebleeds, ‘mild brain trauma’ and ‘white matter tract’ changes.

Several Canadian Embassy employees experienced similar symptoms. Each of the victims reported being targeted either in their homes or in hotels.

The US government has attributed the illness cluster to a series of ‘acoustical attacks’ by a malevolent agent acting with the complicity of the Cuban government. Despite these assertions, no concrete evidence of an attack has been provided.

The episode has been reported as a conundrum because development of acoustic weapons has proved problematic due to an array of physical limitations such as the conspicuous size of any device, the rapid diffusion of the waves and the close proximity required.

Acoustical weapons are bulky, inefficient and impractical, and even if they were able to be focused on a specific target, they are incapable of producing the symptom cluster reported in Cuba. Sound waves below the spectrum of human hearing at 20 Hz (infrasound) are difficult to weaponise due to difficulties in focusing on the wavelengths. Sound waves above the upper range of hearing at 20,000 Hz (ultrasound) dissipate rapidly with distance and would require direct contact from a device to be effective.

These limitations have led military specialists in acoustics to conclude that it is ‘unlikely that high-intensity acoustic energy in the audible, infrasonic, or low-frequency range can provide a device suitable for use as a nonlethal weapon’ (Jauchem, 2007).

There is a consensus among experts on acoustics and human health that something other than a ‘sonic attack’ is responsible for the symptoms in Cuba. British professor of Ultrasonics and Underwater Acoustics, Timothy Leighton, observes that to produce an ultrasonic beam capable of affecting someone 50 m away would require a device the size of a car, and even then the impact would be relatively minor such as difficulty concentrating and anxiety (Devlin, 2017).

The US psychoacoustics specialist Joseph Pompei concurs, ‘Brain damage and concussions, it’s not possible’, as to produce such an effect someone ‘would have to submerge their head into a pool lined with very powerful ultrasound transducers’ (Lederman, Weissenstein, & Lee, 2017).

What attracts much of the media headlines surrounding this case are reports of ‘mild brain trauma’ and ‘white matter tract changes’ in the brain. However, white matter changes are common in a variety of conditions from depression and dementia to the effects of normal aging. There is no evidence that acoustical waves affect white matter tracts or cause concussions, nor is there any plausible pathway as to how this could even happen.

The Federal Bureau of Investigation sent a team of experts to Cuba but found no evidence of a sonic device or other possible agents such as poison (Cerullo, 2018). The irregular patterning of the ‘attacks’ is atypical of an infectious agent. Incidents are confined to diplomats’ homes and the Hotel Capri and Hotel Nacional de Cuba. Based on the nature of the symptoms, their presentation and spread, a possible explanation for the illness cluster is mass psychogenic illness (MPI). This condition is a nervous system disturbance characterized by the rapid spread of illness signs and symptoms among members of a cohesive social group, for which there is no corresponding organic origin. Episodes can be traced to the Middle Ages with reports of St. Vitus Dance across Europe in response to natural disasters such as floods and famine, and stress associated with the Black Death. Outbreaks occur amid a backdrop of anxiety. Prior to the 18th century, most cases were triggered by the fear of witches and demons. Since the 19th century and the rise of scientific rationalism, the majority of outbreaks have occurred in schools and factories, prompted by strict academic or capitalist discipline (Bartholomew & Wessely, 2002).

The socio-political backdrop

The employees affected belong to a common work environment and social network containing a high degree of stress, given the recent waxing and waning political tension between the two countries. The historical context of the ‘attack’ may have contributed to anxieties. During the Cold War, following attempts by US agents to destabilize the Castro regime, Cuban agents responded with a series of ongoing actions that are well known in the diplomatic corps and have become part of American Intelligence folklore. Agents would enter the homes of diplomats and rearrange furniture and bookshelves, deflate their tires and disturb their sleep (Bruno, 2004). Once the administration of US President Donald Trump first identified the illness cluster in February 2017 and defined it as a resumption of Cold War hostilities, its Cuban diplomats were counseled on the ‘mysterious threat’ that was causing colleagues to fall ill (Oppmann & Labott, 2017). This likely created further uncertainty and anxiety. Word of the ‘attacks’ quickly spread through the diplomatic community resulting in several foreign embassies testing their employees for possible exposure. This could explain why a few staff at the Canadian Embassy reported feeling unwell from similar ‘attacks’. It is conspicuous that Cubans working with American diplomats and their neighbors did not experience symptoms.

Counseling staff over the perceived threat created an expectation of illness and a new frame through which to interpret future sounds and symptoms. The events in Cuba parallel reports of illness clusters in the vicinity of wind farms that have been attributed to the infrasonic sounds of the turning blades.

In healthy volunteers exposed to wind turbine sounds, positive and negative expectations were shown to affect the symptoms that were attributed to the sound. Negative expectations increased the frequency and intensity of symptoms; positive expectations engendered a reduction in symptoms. Hence, framing the turbine sound in more benign or neutral ways could potentially nullify the negative effects (Crichton et al., 2014). These results could be instructive if the Trump administration adopts a counter-narrative as to the origin of the outbreak.

Historical acoustic scares

The Cuban saga has historical antecedents. In 1992, several residents of Taos, New Mexico reported feeling ill after hearing a mysterious humming sound. Symptoms included headaches, general discomfort, insomnia and ear pain. A US government-funded study of the ‘Taos Hum’ failed to identify an acoustic, seismic or electromagnetic origin, prompting researchers to shift their inquiry from the physical environment to those reporting the sound and symptoms. Frosch (2016) concluded that a majority of sufferers were likely experiencing tinnitus. Between 1999 and 2002, about 100 residents of Kokomo, Indiana, reportedly became ill after hearing a mysterious intermittent humming sound. Symptoms were headaches, lightheadedness, muscle and joint pain, insomnia, fatigue, nosebleeds and diarrhea. In 2002, the Kokomo City Council allocated USB $100,000 for an environmental consulting firm to study ‘The Kokomo Hum’. No acoustical origin was identified (Cowan, 2002). More recently, the Canadian government allocated CAD $60,000 to study ‘The Windsor Hum’ in Ontario province. It was concluded that the source of the sound was from blast furnaces at a nearby US steel mill (Novak, 2014).

The politics of mass psychogenic illness

The handling of the outbreak by the Trump administration has exacerbated the episode due to its contradictory claims and the use of ambiguous, dramatic descriptions such as ‘brain trauma’ and ‘white matter tract changes’. The vague character of the symptoms and the attributed cause (sound) are conducive to the mechanism of contagion because the symptoms can arise from several clinical conditions including tinnitus, while sounds are common in the environment. Publicity surrounding the events have served to reaffirm, magnify and propagate the suggestive effect.

The US State Department officially revealed the existence of the ‘attacks’ on 9 August 2017. Since this time, the Trump administration has expelled several Cuban diplomats serving in the United States as retaliation. The ranking members of the Senate Intelligence Committee have urged the administration to declare Cuban diplomats in the United States persona non grata and close the American Embassy in Cuba, unless ‘the harassment and acoustic attacks’ cease (Rubio, 2017).

MPI has stoked political tensions in the past. In 1983, nearly 1,000 mostly Arab schoolgirls in the disputed Israeli-occupied West Bank were reportedly poisoned by Jewish agents, prompting the United Nations to pass a resolution condemning the ‘attack’ and threats of war. Symptoms included fainting, headache, abdominal pain, blurred vision and muscle weakness. Three separate investigations concluded that the outbreak was MPI, triggered by odor from a school latrine (Landrigan & Miller, 1983Modan et al., 1983) and propagated by inaccurate media reports (Hafez, 1985).


MPI poses a significant public health challenge as the diagnosis is often contentious and can inflame international relations. The initial outbreak prompted the State Department to warn diplomatic staff traveling to or in Cuba to be aware of the illness cluster, generating more anxiety and intensifying the outbreak. The ‘sonic attack’ claims also provided a convenient ‘catch all’ category for a variety of staff to place an array of ambiguous, ever-present ailments and sounds that were redefined as related to the ‘acoustical attack’. Since news of the ‘attacks’ was first made public in August 2017, nearly three dozen American tourists have contacted the Associated Press to report that upon visiting Cuba within the past 4 years, they had heard noises and experienced symptoms similar to the affected diplomats and believed that they too had been attacked (Lederman, 2017).

The ambiguous nature of the complaints, their irregular patterning in hotels and homes, the physical limitations of sonic weapons and the absence of concrete evidence, all point to MPI exacerbated by mundane sounds and Cold War beliefs. During the Senate Hearing on the ‘sonic attacks’, State Department Medical Director Dr Charles Rosenfarb said that when the initial cluster appeared, he immediately consulted a specialist in acoustical weaponry due to the accompanying sounds (Rubio, 2018). His actions call to mind the medical adage: ‘When you hear the sound of hoofbeats, first think horses, not zebras’. In this instance, the sounds are more likely to have been the mundane noises of everyday life, crickets, cicadas and tinnitus, framed within the historical context of antagonistic Cuban–American relations. The episode exemplifies the power of beliefs and its potential in triggering psychiatric conditions.


On 15 February 2018, Swanson et al. published the preliminary findings of a study of 21 of the 24 patients affected in the Journal of the American Medical Association. They found that each of the patients ‘appeared to have sustained injury to widespread brain networks without an associated history of head trauma’. Their conclusions include assumptions that are unverified. For instance, they presumptuously wrote that the purpose of their study was ‘To describe the neurological manifestations that followed exposure to an unknown energy source associated with auditory and sensory phenomena’. This claim is yet to be confirmed by objective medical measures.

There are several reasons to exercise caution in interpreting their findings. The patients completed a battery of medical tests, on average, 203 days after onset, making it difficult to determine an accurate timeline of the evolution of symptoms and whether subjects were aware of preceding reports. Furthermore, the authors dismiss the possibility of MPI because the patients were not malingerers as they expressed a desire to go back to work. This does not eliminate the possibility of conversion disorder and suggests that they are not fluent in the MPI literature. They marginalize the condition as being in the category of ‘collective delusional disorders’; in reality, there is a psychiatric consensus that it is a collective stress response common in normal individuals. In dismissing the role of conversion disorder, they note that MPI is typified by a ‘rapid onset and recover’. Howevery, Wessely (1987) has identified two main types. The first ‘anxiety hysteria’ involves the sudden exposure to a perceived harmful agent, most commonly a strange odor, in a close-knit group lacking pre-existing tension and usually involves rapid onset and recovery. The second type, ‘motor hysteria’, is more enduring, is typified by neurological dysfunction and incubated over weeks or months. Cases often take months and occasionally years to subside once the stressful agent is believed to have been eliminated.

In an accompanying editorial, Muth and Lewis (2018) also urge caution, observing that brain imaging revealed ‘nonspecific white matter changes in some individuals, but was otherwise unrevealing’. As for their main finding of concussion-like symptoms, they are equally skeptical as many of the complaints ‘occur in other medical, neurological, or psychiatric conditions’. The symptoms overlap with a variety of conditions ranging from postural–perceptual dizziness to vestibular migraine.

In a commentary in the same issue, Rubin (2018) was also cautious, citing an interview with S. Andrew Josephson, chair of neurology at the University of California, San Francisco, School of Medicine, who observed that ‘There’s not something on the conventional magnetic resonance imaging (MRI) … that you can point to and definitively say there is a common issue’. He notes that most of the neuroimaging data are either normal or nonspecific, suggesting the absence of a structural injury.

American Associates, Ben Gurion University of the Negev
Media Contacts:
Andrew Lavin – American Associates, Ben Gurion University of the Negev
Image Source:
The image is credited to U.S. Embassy in Cuba.

Original Research: The findings will be presented at the Breaking the Barriers of Brain Science Symposium in New York.


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