New Study Reveals Long COVID Damages Dopamine-Producing Brain Neurons
A new brain-imaging study reveals that long COVID damages dopamine-producing neurons in the brain, explaining persistent symptoms like fatigue, memory issues, and loss of motivation.
A new brain-imaging study conducted by scientists at the Centre for Addiction and Mental Health (CAMH) in Canada and published in the scientific journal eBioMedicine has revealed that long COVID causes damage to brain cells that release dopamine, a chemical messenger responsible for motivation, movement, and pleasure. According to the researchers, this discovery explains persistent symptoms experienced by patients, such as loss of movement speed, memory issues, and a lack of motivation.
Brain Scan Insights and Dopamine Decline
Long COVID is estimated to affect roughly five percent of the global population, including about two million people in Canada alone, with symptoms lingering for at least three months post-infection. Previously, evidence-based treatments were lacking largely because scientists did not fully understand the underlying neurological mechanisms.
Using advanced PET scans—a imaging technique measuring biological brain activity—the researchers tracked a marker indicating dopamine cell health. Long COVID patients exhibited significantly lower marker levels in the striatum, an interconnected group of brain regions regulating motivation, movement, and cognitive thought. Different patterns of dopamine depletion correlated directly with specific symptoms:
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Lower levels in the lower striatum linked to loss of motivation.
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Reduced activity in movement-controlling areas tied to slowed physical movement.
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Decreased levels in the caudate nucleus associated with cognitive and memory difficulties.
"Our findings provide compelling evidence that long COVID involves a loss of dopamine-producing neurons," explained Dr. Jeffrey Meyer, a senior scientist at the CAMH Brain Health Imaging Centre and lead author of the study. "This type of injury is well known to produce symptoms like lack of motivation and motor slowing, and may contribute to memory difficulties in other neurological conditions."
Potential Treatments and Future Clinical Trials
Dr. Meyer noted that these findings build upon previous research demonstrating high levels of neuroinflammation in dopamine-rich brain areas among long COVID sufferers. While past studies highlighted inflammation, the current research directly connects lower dopamine marker levels with patient-reported symptoms, suggesting that long COVID is, at least in part, a dopaminergic system disorder.
Researchers plan to launch a clinical trial in the coming months in collaboration with the University Health Network (UHN) and funded by the Canadian Institutes of Health Research (CIHR). The upcoming trial will explore repositioning existing medications that enhance dopamine function—such as dopamine precursors and enzyme inhibitors—to determine whether cognitive function, motivation, and fatigue can be effectively restored in long COVID patients.
