Overview
Two new government studies conducted at the National Institutes of Health (NIH) in Bethesda found no unusual pattern of injury or illness in people with Havana syndrome. The findings challenge the theory that diplomats and intelligence workers have been targeted by foreign adversaries.
Study Design
- Participants: More than 80 individuals thought to have Havana syndrome compared with dozens of similar control subjects without symptoms
- Duration: Participants spent approximately one week at NIH receiving extensive evaluations
- Testing included: Cognitive, auditory, vision, ocular motor, vestibular, balance assessments and blood biomarker testing
- Imaging: Two separate brain scans per participant
- Control groups: Carefully matched for age, profession, and location to affected individuals
Key Findings
No Structural Brain Differences
Dr. Leighton Chan of NIH reported: "We didn't see differences in brain volumes or other metrics that look at the structure of the brain or even in the functional connectivity of the brain."Psychological Symptoms More Prevalent
The studies found people with Havana syndrome symptoms were more likely to report:- High levels of fatigue
- Depression
- Post-traumatic stress
Researcher Perspectives
Dr. Carlo Pierpaoli (NIH imaging expert)
> "We were very careful about designing the imaging study as a research study with very high reproducibility."Dr. Louis French (Walter Reed National Military Medical Center neuropsychologist)
> "Some of these people are in distress. Many people are sad and feel overwhelmed, and so we are doing our best to try to address some of that distress that's associated with them feeling sick."Criticisms and Limitations
Dr. David Relman (Stanford University)
In an editorial accompanying the new research, Relman identified two key problems: 1. Methodological limitations: "The inadequacy of currently available methods for detecting the kind of brain disruption that may be involved in some of these cases." 2. Study design issue: The studies may have lumped together people who actually sustained a brain injury with those whose symptoms have psychological explanations, making it harder to detect differences.Relman stated: "And one of the problems is the inadequacy of currently available methods for detecting the kind of brain disruption that may be involved in some of these cases."
Context and Implications
Comparison with Prior Research
The NIH findings stand in contrast to a 2019 University of Pennsylvania imaging study that found subtle changes in the brains of affected people.Government Terminology Shift
The U.S. government now refers to Havana syndrome cases as "anomalous health incidents" (AHI).Attribution vs. Medical Research
Dr. Leighton Chan emphasized: "Medical research may not be the answer to this if what you're looking for is attribution. The answer to this is counterintelligence - somebody taking a photo of somebody doing this, somebody actually getting whatever it is."Related Pages
- havana-syndrome-medical-findings — Medical documentation of neurological manifestations among U.S. government personnel reporting directional audible and sensory phenomena
- gaov-havana-syndrome-report-2024 — GAO report documenting systemic failures in military healthcare delivery for Havana Syndrome patients
- havana-guangzhou-embassy-cases — U.S. Embassy Havana (late 2016) and Consulate Guangzhou cases involving directional auditory symptoms
- friedman-calkin-havana-canadian-diplomats-2019 — First multimodal brain imaging documentation of acquired neurotoxicity in diplomats exposed to Havana Syndrome