Senior neurologists have suggested that a spate of mysterious ailments among US diplomats in Cuba – which has caused a diplomat rift between the two countries – could have been caused by a form of “mass hysteria” rather than sonic attacks.



The unexplained incidents have prompted the US to withdraw most of its embassy staff from Havana and expel the majority of Cuban diplomats from Washington.

The neurologists who talked to the Guardian cautioned that no proper diagnosis is possible without far more information and access to the 22 US victims, who have suffered a range of symptoms including hearing loss, tinnitus, headaches and dizziness.

The state department has described the incidents as “attacks”, saying they began at the end of last year with the last recorded incident in August.

But US and Cuban investigations have produced no evidence of any weapon, and the neurologists argue that the possibility of “functional disorder” due to a problem in the functioning of nervous system – rather than a disease – should be considered.



“From an objective point of view it’s more like mass hysteria than anything else,” said Mark Hallett, the head of the human motor control section of the US National Institute of Neurological Disorders and Stroke.

“Mass hysteria” is the popular term for outbreaks among groups of people which are partly or wholly psychosomatic, but Hallett stressed there should be no blame attached to them.

“Psychosomatic disease is a disease like anything else. It shouldn’t be stigmatised,” said Hallett, who is also president of the International Federation of Clinical Neurophysiology. “It’s important to point out that symptoms like this are not voluntary. They are not a sign of weakness in an individual’s personality.”

Hallett said it was more common for such disorders to affect smaller groups of people, often in families, but he added that it was feasible for larger numbers of individuals to be affected, especially when they were working closely together in a tense and hostile environment.

“There are a very large number of individuals that have relatively vague complaints as far as I can see,” Hallett said. “There has been an exploration of possible causes for this and nothing has been found and the notion of some sonic beam is relatively nonsensical.

“If it is mass hysteria that would clarify all the mystery – and presumably normalise US-Cuban relations again,” said Hallett. “These people are all clustered together in a somewhat anxious environment and that is exactly the situation that precipitates something like this. Anxiety may be one of the critical factors.”

The Associated Press reported on Thursday that it had been provided audio tapes of high-pitched whining noises which some US embassy workers said they heard in Havana, but it is unclear whether the sounds were linked to the health complaints. The report noted that not all the Americans injured in Cuba heard sounds, and of those who did, it is not unclear if they heard the same thing.

Alan Carson, a consultant neuropsychiatrist and former president of the British Neuropsychiatry Association told the Guardian: “Typically what one gets in a functional disorder is some trigger. It is often relatively mild and non-specific, it can be a minor physical injury. But then a combination of a degree of anxiety and also belief and expectation distort that feeling.”

“If there is a strong enough expectation that something is going to happen, that will distort in an entirely real way the incoming information,” Carson said. “In certain circumstances that can be transmitted from person to person... If one person has that experience strongly enough and sets off that train of thought in somebody’s else’s mind, that can happen too.”

Many acoustics experts have said that it is highly unlikely that the range of symptoms reported could have been caused by any kind of sonic weapons.

Another theory was that the health complaints were caused by a surveillance operation that had gone wrong – but that has also met with scepticism from experts and a dearth of evidence.

The US has not directly blamed the Cuban government but said Havana had failed in its obligation to protect foreign diplomats on its territory. The Cuban government has denied conducting any form of attack and has offered its cooperation in discovering the cause of the symptoms.

“I don’t think the Cuban government is behind it,” said Ben Rhodes, Barack Obama’s foreign policy adviser, who was involved in negotiating the previous administration’s rapprochement with Havana.

“First, these things apparently started in December … At the same time the attacks were starting the Cuban government was frantically concluding agreements with us, signing business deals … in other words trying to preserve the relationship. So the notion that at the same time as doing that, they would initiate something that is so obviously designed to blow up the relationship doesn’t make any sense.”



Asked about the possibility of functional disorders, a state department spokesperson said: “We have no definitive answers on the cause or the source of the attacks on US diplomats in Cuba, and an aggressive investigation continues. We do not want to get ahead of that investigation.”

Donald Trump has struck a markedly more hostile tone towards Cuba than his predecessor, and in June announced a partial rollback of Obama’s rapprochement, tightening travel and trade rules with the island.

Jon Stone, a University of Edinburgh neurologist and the co-editor of a book on functional neurologic disorders, said that such disorders were very common, and the second commonest reason to see a neurologist.

“There is a misconception that only people who are weak-willed, people who are neurotic, get these symptoms. It isn’t true,” Stone said. “We are talking about genuine symptoms that people have of dizziness, of headaches, of hearing problems, which they are not faking.”

He added that the outbreak could have started with one or two people falling ill with headaches or hearing problems, and those spread in a high-stress atmosphere and then amid talk of a “sonic attack”.

“None of this makes sense until you consider the psychogenic explanation,” said Robert Bartholomew, a medical sociologist and the author of series of books on outbreaks of mass hysteria.

“American intelligence agencies are the most sophisticated in the world, and they reportedly don’t have a clue as to what’s causing the symptoms. I will bet my house that there are agents in the intelligence community who have also concluded that this is a psychogenic event – but their analysis is either being repressed or ignored by the Trump administration because it doesn’t fit their narrative. Mass psychogenic illness is by far the most plausible explanation.”