Confusion, anxiety and mental fog. These are some post Covid symptoms that have become the subject of scientific studies and research. These are psychological consequences left by the Covid virus. For some time, experts have been investigating the psychological consequences of covid which, even months after recovery, seems to leave aftermath to many people who report feeling confused, anxious or not very concentrated, wrapped in a so-called mental fog. A Newscientist article takes stock of the situation by summarizing what has emerged from the studies conducted so far: these symptoms would not be the direct consequence of a virus attack on the brain, but rather a collateral damage of the immune response unleashed to fight the infection. There are already viruses that affect and damage the brain, such as measles, polio or flu. However, this would not be the case with SARS-CoV-2: while it is true that the coronavirus can enter the brain, it does not seem to replicate or damage its tissues and cells.

Mental health: post Covid confusion, anxiety and difficulty concentrating

IMMUNE RESPONSE. Several studies have come to the same conclusion, namely that mental fog is the consequence of inflammation caused by the body’s immune response to infection: looking at the cerebrospinal fluid of some patients infected with covid, the researchers found that some immune cells they produced chemicals that were potentially toxic to brain cells; a German study carried out on deceased patients also showed an increase in the activity of microglial cells, the immune cells of the central nervous system.

PARALLELISMS. According to neuro-oncologist Michelle Monje, of Stanford University, there are parallels between the symptoms of long covid mental fog and the chemo brain (literally chemo brain), the difficulty in remembering and thinking clearly experienced by those who have just finished a course of chemotherapy. Post-chemo symptoms appear to be caused by the body’s immune response in reaction to drugs that leads to a release of chemicals that damage brain cells and cause inflammation particularly in microglial cells, the same inflamed immune cells in the brain. deceased patients in Germany.

FOREVER? The good news is that the symptoms of mental fog appear to be reversible, although it is still unclear how long after recovery they can occur: a 2021 study found that a third of those recovered had cognitive impairment or neurological even six months after infection. “We want to conduct further research to understand what happens after 12 or 18 months,” explains Maxime Taquet, coordinator of the study.