A new brain imaging study is raising questions about one of the most widely discussed explanations for long COVID. Researchers found no evidence of widespread brain inflammation in people experiencing lingering symptoms after COVID-19 infection. Instead, patients with more severe symptoms showed increased activity in brain regions linked to emotion, stress, and memory.

Long COVID has often been suspected to involve ongoing inflammation in the brain caused by SARS-CoV-2 infection. Scientists have explored this theory as a possible explanation for symptoms such as fatigue, brain fog, anxiety, and depression.…