Susan Deuville caught COVID in 2021 and never fully recovered. In the years since, she has lived with the fatigue, brain fog, and loss of motivation that have become defining symptoms of long COVID for millions of people.
Deuville was a part of a new study that used brain scans to find signs of damage in the parts of the brain that produce dopamine, and the pattern of that damage varied by region in ways that matched each patient's specific symptoms.
The study, led by researchers at the Centre for Addiction and Mental Health in Toronto and published in eBioMedicine, provides some of the most direct evidence yet that long COVID affects the brain's dopamine system, building on earlier work from the same team that had found inflammation in these same regions.
“For five years I have been seeking answers on what happened to me after I contracted COVID in 2021,” said Deuville, lived experience research advisor to senior study author Jeffrey Meyer, in a press release. “It was a crushing loss of the life I had and the person I was before. The research of Dr. Meyer brings hope. It also validates what long COVID sufferers have always known — long COVID is real and the effects are devastating.”
Long COVID Brain Scans Show Dopamine System Changes
Researchers used a specialized brain scan capable of detecting how many dopamine-releasing nerve endings remain intact in a given brain region. They compared scans from 24 adults with long COVID to those of 24 healthy adults matched for age, later expanding the healthy comparison group to 43 for additional analyses.
Lower marker levels in the ventral striatum, a region involved in motivation and reward, were tied to apathy, and lower levels in the dorsal putamen, which helps control movement, were tied to slower physical responses. Both of those links were part of the study's main planned analysis.
A third link, between lower levels in the dorsal caudate, a memory-related region, and worse recall, turned up only in additional testing done afterward, so it carries less weight than the other two. Across all three regions, the marker ran roughly 16 to 20 percent lower than in healthy adults of the same age.
It's worth being clear about what the scans can and can't show. They don't count neurons directly or measure dopamine itself, only a marker linked to nerve-terminal density. That means the findings point to injury within the dopamine system without yet establishing whether the change is permanent or whether long COVID itself is the direct cause.
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Dopamine Changes Could Point to New Long COVID Treatments
Long COVID is estimated to affect about 5 percent of the global population. Until now, treatment options for those neurological symptoms have been almost nonexistent, with most prior research concentrated on brain inflammation rather than on whether the dopamine system itself was affected.
“Long COVID is, at least in part, a disorder of the brain’s dopamine system,” added Meyer in the press release. “This suggests that repurposing medications that augment the function of dopamine-releasing neurons, including dopamine precursors and inhibitors of dopamine metabolism, could be a promising approach.”
Meyer and his colleagues are organizing a clinical trial to test whether restoring dopamine activity can ease fatigue, memory loss, and lack of motivation in long COVID patients. They note that a correlation seen on a scan doesn't yet prove that fixing one problem will fix the other, and that the study's relatively small size means larger trials will be needed to confirm the findings.
The scan may not be able to undo years of unanswered questions, but for Deuville and thousands of others living with long COVID, it offers physical evidence that something real is happening inside their brains and a place to start looking for a solution.
Read More: Catching COVID-19 or the Flu Could Triple Your Risk of Stroke and Heart Attack
This article is not offering medical advice and should be used for informational purposes only.
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
- This article references information from a study published in eBioMedicine: Loss of vesicular monoamine transporter 2 in striatum of long COVID and relationship to neuropsychiatric symptoms
