Chapter 1: Understanding 'Havana Syndrome'

Imagine being a diplomat, intelligence analyst, or officer stationed in an unfriendly nation. You’re resting in your accommodation—be it an embassy, hotel, or safe house—when suddenly, you experience an unsettling pressure in your head along with a ringing sound. This sensation may be coupled with feelings of dizziness and confusion. Intriguingly, the discomfort seems to emanate from a specific direction, and as you move around the room, the sensations fluctuate, intensifying in certain spots. Is it possible you are under attack?

The collection of symptoms I’m referring to is officially termed "Anomalous Health Incidents" (AHIs), a term as vague as "Unidentified Flying Object." However, you may recognize this phenomenon by its more common name: Havana Syndrome. The first reports emerged in 2016 from U.S. personnel in Cuba, and since then, similar cases have surfaced among U.S. government employees in locations like China, Europe, and even Washington D.C., resulting in a significant increase in reported incidents.

The media quickly speculated about foreign involvement, with headlines implying that these symptoms were likely caused by some form of weaponry.

However, as the number of reported cases grew, the theory of a mysterious ray gun began to lose credibility. Would multiple countries really possess such technology? Furthermore, what would be the purpose of a weapon that neither kills nor incapacitates? It seemed increasingly likely that the notion of secret weapons was relegated to conspiracy theories.

Alternative explanations for the syndrome exist beyond the idea of exotic weaponry. The affected individuals endure immense stress, often in roles shrouded in secrecy within potentially hostile territories. Some theorists propose that Havana Syndrome may actually stem from mass hysteria—an epidemic of fear, fueled by stories and media coverage, which exacerbates stress levels among diplomats and intelligence officers.

The distinction between a psychological disorder and a deliberate attack is crucial. One requires therapeutic intervention, while the other might warrant a defensive response. Understanding this issue has significant implications not only for scientific inquiry but also for national security.

Ongoing investigations have explored this phenomenon from various angles, including studies on animals. Reports indicate that the Pentagon has been experimenting with directed energy weapons on ferrets to replicate the syndrome.

Today, we will delve into the latest findings from the National Institutes of Health's AHI Intramural Research Team, who conducted extensive testing on individuals with Havana Syndrome. Their findings are detailed in two recent papers published in JAMA.

The first study involved 86 patients diagnosed with Havana Syndrome through federal channels. Approximately half exhibited classic symptoms, while others presented with less conventional signs. The research also included a control group of 30 asymptomatic individuals with similar professional backgrounds.

The cases were notably severe, with one-third of participants experiencing a reduced ability to work due to persistent symptoms. It is important to note that the study participants were not perfectly matched with the control group beforehand. Those who ultimately developed Havana Syndrome had higher instances of depression, tinnitus, and peripheral neuropathy prior to the incident, and these rates surged after.

Examining the changes over time reveals a consistent pattern: the majority of alterations involve subjective experiences—difficult to quantify through traditional medical tests. Following an AHI, patients report heightened levels of depression, increased headaches, sleep disturbances, cognitive issues, dizziness, and balance problems.

Are these symptoms reflected in measurable biomarkers? A comprehensive array of factors was assessed in the study, but the short answer is no. Formal neurocognitive evaluations indicated no significant differences between those with Havana Syndrome and the control group regarding intelligence, memory, processing speed, or reasoning capabilities.

Blood tests for glial fibrillary acidic protein and neurofilament light chain (which indicate brain injury) showed no variation between the groups.

The second JAMA paper employed advanced MRI techniques to investigate brain structure, including overall volume, white and gray matter, and connectivity. The results showed negligible differences between the affected individuals and the control group, with the only exception being a slightly larger corpus callosum in the former—contrary to expectations following a brain injury.

The heat map of all measured factors highlights a single area of significant difference: psychological assessments.

Those with Havana Syndrome exhibited considerably worse scores on the Beck Depression Inventory, more severe PTSD symptoms, and lower overall life satisfaction.

In summary, while these individuals are indeed suffering, the testing fails to clarify the reasons for their distress. The evidence increasingly points away from the theory of a foreign weapon. The CIA has issued a report suggesting that it is improbable the syndrome results from an adversarial attack. Whether this conclusion reassures the public, given current trust in government agencies, remains uncertain. Congress has expressed dissatisfaction and plans to independently investigate the CIA's findings.

There are numerous uncertainties in this situation. If these studies are accurate, and if the participants are representative of the broader population with Havana Syndrome, and if the intelligence available to certain agencies aligns with these results, it appears that the syndrome may be a manifestation of depression and PTSD influenced by the perceptions of those in a hostile context. Conversely, if not… perhaps skepticism is warranted.

A version of this commentary first appeared on Medscape.com.

Chapter 2: The Latest Findings on Havana Syndrome

Recent investigations have raised questions regarding the origins and implications of Havana Syndrome. For more insights, view the following videos.

The first video titled "The Most Extensive Study Yet of 'Havana Syndrome' Turns Up… Nada?" discusses the findings of a comprehensive study that suggests no significant differences in biomarkers between affected individuals and controls.

The second video, "Havana Syndrome Evidence Suggests Who May Be Responsible for Mysterious Brain Injuries," explores potential factors and individuals behind this perplexing syndrome.