Researchers employed a specialized brain imaging technique to identify a potential biomarker and therapeutic target for Long COVID. Despite how widespread Long COVID is, its root causes remain unclear. The systemic increase in AMPARs provides a direct biological explanation for the cognitive symptoms, highlighting a target for potential treatments. For example, drugs that suppress AMPAR activity could be a viable approach to mitigate brain fog. “Our findings clearly demonstrate that Long COVID brain fog should be recognized as a legitimate clinical condition.