People who experience anxiety and depression months after a mild case of COVID-19 may have changes that affect the structure and function of their brains.
Researchers from the University of Campinas in São Paulo studied 254 people who had a mild COVID-19 infection. On average, the patients were 41 years old and had COVID-19 three months earlier. Each participant completed tests for symptoms of anxiety or depression and underwent brain scans. In all, 102 people had symptoms of both anxiety and depression, and 152 had neither, the researchers found.
The researchers then looked for evidence of shrinkage in the brain’s gray matter. The scans were compared to those of 148 people who had not had COVID-19. Those who had COVID-19 and experienced anxiety and depression had a shrinkage in the limbic area of the brain, which is involved in memory and emotional processing. Those who did not have symptoms of anxiety and depression after COVID-19 did not experience brain shrinkage.
Using a special type of software to analyze networks with resting-state brain activity, the researchers also looked at brain function and changes in connectivity between brain areas. They did this in 84 people in the symptom-free group; 70 people from the anxiety and depression group; and 90 people who did not have COVID-19. The researchers found widespread functional changes in each of the 12 networks they tested in the group with symptoms of anxiety and depression. The symptom-free COVID group also had changes, but in five instead of 12 networks.
The results suggest a severe pattern of changes in the way the brain communicates and in its structure, primarily in people with anxiety and depression with long-term COVID syndrome, which affects so many people. The magnitude of these changes suggests that they could lead to problems with memory and thinking skills, so we need to explore treatments even in people mildly affected by COVID-19.
These findings were made public on February 20 ahead of their presentation in Boston and online at a meeting of the American Academy of Neurology April 22-27.