Long COVID symptoms linked to measurable damage in the brain's dopamine system

Key Points:

• A study published in eBioMedicine found that individuals with long COVID exhibit an approximate 18% reduction in dopamine-releasing neurons in key brain regions, correlating with symptoms like apathy, memory problems, and slowed physical movement.
• Researchers used positron emission tomography to measure vesicular monoamine transporter 2 (VMAT2) protein levels, a marker of dopamine neuron integrity, in 24 long COVID patients compared to healthy controls, revealing significant decreases linked to neuropsychiatric symptoms.
• The findings suggest that dopamine dysfunction may underlie some long COVID symptoms and highlight the potential for dopamine-enhancing treatments to improve motivation, cognitive function, and motor speed in affected patients.
• Limitations include the small sample size, focus on neuropsychiatric symptoms rather than other long COVID manifestations, and the inability to determine causality or permanent neuron loss from this observational, single time-point study.
• An accompanying commentary emphasized that these brain changes reveal measurable biological correlates of long COVID symptoms invisible to standard MRI scans and called for larger, longitudinal studies combining various brain imaging techniques to better understand and treat the condition.