A recent Canadian study has shed light on the potential biological causes of memory issues and cognitive impairment experienced by some individuals after recovering from COVID-19. The study, published in the journal eBioMedicine in 2026, used positron emission tomography (PET) scans to examine 24 individuals with long-haul COVID-19 and compared them to 24 healthy individuals of similar ages. The researchers focused on a protein called VMAT2, which is abundant in neural terminals that release dopamine in the brain.
The study found that the VMAT2 protein signal was lower in individuals with long-haul COVID-19 in the areas of the brain examined. Notably, the location of the signal correlated with specific symptoms: reduced motivation and apathy were linked to decreased signal in one area, slowed movement in another, and memory complaints in a third. The findings suggest that COVID-19 may be associated with changes in brain function, particularly in regions involved in motivation, movement, and memory.
The researchers emphasize that the PET scan measures the binding of a tracer to the VMAT2 protein and does not directly show dead neurons or prove that COVID-19 is the sole cause of the observed changes. Additionally, the study's small sample size and lack of longitudinal data limit the conclusions that can be drawn. Further research is needed to confirm the findings and determine whether the changes are permanent.
Despite these limitations, the study provides valuable insights into the experiences of individuals with long-haul COVID-19, who often report difficulties with memory and cognitive function. The researchers suggest that their findings may have implications for the development of targeted treatments in the future. However, at present, there is no evidence that medications that boost dopamine can restore memory.
The study's lead author, Liao, and colleagues are cautious in their interpretation of the results, emphasizing that the findings are exploratory and require replication in larger studies. Nevertheless, the research represents an important step forward in understanding the biological mechanisms underlying post-COVID-19 cognitive impairment.
The study's results are consistent with reports from patients who have experienced persistent cognitive symptoms after recovering from COVID-19. These individuals often describe difficulties with memory, concentration, and mental processing, which can be debilitating and affect daily life. By exploring the biological basis of these symptoms, researchers hope to develop effective treatments and improve the lives of those affected.
The research community continues to investigate the long-term effects of COVID-19 on brain function and cognitive health. As the pandemic has shown, COVID-19 can have far-reaching consequences for individuals and society, and it is essential to understand and address these effects to provide adequate support and care for those affected.
Key points
- Researchers found a possible link between COVID-19 and changes in the VMAT2 protein in the brain, which may contribute to memory issues and cognitive impairment.
