Is Havana Syndrome real or just a kind of mass delusion? That question is circulating again because last week Buzzfeed published a previously secret report which concluded in 2018 that the sounds recorded of alleged attacks were in fact, probably crickets.

The State Department report was written by the JASON advisory group, an elite scientific board that has reviewed US national security concerns since the Cold War. It was completed in November of 2018, two years after dozens of US diplomats in Cuba and their families reported hearing buzzing noises and then experiencing puzzling neurological injuries, including pain, vertigo, and difficulty concentrating.

The report, obtained by BuzzFeed News via a Freedom of Information Act request, was originally classified as “secret.” It concluded that the sounds accompanying at least eight of the original 21 Havana syndrome incidents were “most likely” caused by insects. That same scientific review also judged it “highly unlikely” that microwaves or ultrasound beams — now widely proposed by US government officials to explain the injuries — were involved in the incidents. And though the report didn’t definitively conclude what caused the injuries themselves, it found that “psychogenic” mass psychology effects may have played a role.

The issue here is that some of the people who claimed they were attacked in this way made audio recordings of what they heard. After listening to those recordings, the JASON group said they sound most like a specific type of very loud cricket. However, there’s more to it than that.

One of the arguments made in favor of pulsed microwave attacks was something called the Frey effect. The Frey effect is thought to be a reaction of the ear to microwave exposure which results in pops or clicking sounds. However, because those sounds are produced directly in the ear, they are not audible to someone standing nearby. In other words, if the Frey effect were happening, they should not be able to make an audio recording of the sound.

James Lin, a University of Illinois biomedical engineer who has argued that the microwave explanation for the injuries is very likely, told BuzzFeed News that the recordings of incidents analyzed in the JASON report provided by at least eight victims could not have come from real cases of Havana Syndrome. “A typical sound recorder would not be able to record the ‘microwave sound’, period,” he said by email, after reviewing the JASON report’s findings.

But today, McClatchy reports the White House is pushing back against claims that Havana Syndrome is some kind of mass delusion. In fact, they recently issued a warning about it to national security staff.

The U.S. government is sending a message to diplomats, national security staff and intelligence officers that “anomalous health incidents” — also known as “Havana syndrome” because it was first detected in Cuba — are serious, widespread and pose real danger to their health at home and abroad.

The new workplace guidance is part of a broader strategy by the Biden administration to act with greater speed on reported cases, after finding that quicker action benefits the health of the victim and the investigation of the incident…

The official disputed that the syndrome may have been “mass hysteria,” saying, “The physical effects we’ve seen in several cases are very, very real.”…

While some cases after review do turn out to be unrelated to “Havana syndrome,” there are enough convincing cases to establish a clear pattern, officials say.

Just last month the BBC reported that recent cases of Havana Syndrome showed distinct markers in the blood that could be detected within a few days of the incident. Those markers fade fairly quickly, meaning that people who reported an attack months ago can’t be tested retroactively.

Still, it sounds like there could be two things going on here. One is actual attacks of some kind which create real damage and leave traces and the other is people who wrongly become convinced they were targeted because they hear about it from others in their line of work. That’s not to say those people are lying but perhaps some of them are simply wrong.