https://www.colorado.edu/today/2024/08/19/low-cortisol-may-play-role-fueling-long-covid-study-suggests

He theorizes that the process might go something like this: COVID antigens lower cortisol, which serves to keep inflammatory responses to stressors in check in the brain. Once a stressor arises—whether it be a bad day at work, a mild infection or a hard workout—the brain’s inflammatory response is unleashed without those limits and serious symptoms come screaming back.

Those might include fatigue, depression, brain fog, insomnia and memory problems.

Frank said he is doubtful that cortisol treatments alone could be an effective treatment for long COVID, as they would not get at the root cause and come with a host of side effects.

Rooting out the source of antigens—including tissue reservoirs where bits of virus continue to hide out—might also be an approach worth exploring.