Cell magazine has published a study conducted several months after COVID-19 with patients with symptoms of permanent COVID-19. According to him, symptoms of permanent COVID-19 may be related to decreased serotonin. They also propose a mechanism to explain it.
The study was conducted by researchers from Penn University. After analysis of stool samples from patients with permanent COVID-19, it was observed that some had sequelae of SARS-CoV-2 virus. It was inferred that the virus compounds remained in the intestine, and they found that they activated the immune system response. In particular, they produced anti-interferon proteins.
It is explained that interferons cause inflammation of the intestine which prevents the correct absorption of the amino acid tryptophan. This amino acid is part of several neurotransmitters that are produced in the intestine, including serotonin. And serotonin plays a fundamental role in many of the major functions that connect the brain and body: it regulates memory, sleep, digestion and nerve vagus. Therefore, researchers believe that lowering the level of serotonin can cause some typical symptoms of permanent COVID-19: having a “bruised” head and concentration problems, memory loss, fatigue…
Moreover, mice have shown that increasing serotonin levels improves memory problems. According to the researchers, this opens the way to testing treatment with patients with low serotonin levels.