According to a study, patients with persistent symptoms of depression and cognitive impairment after mild to moderate Covid-19 infection had elevated levels of the protein, which indicates brain inflammation.
Many patients have been found to have long-lasting symptoms of COVID-19, often referred to as long COVID. Psychiatric symptoms such as anxiety and depression are most common and can last for weeks, even months, after recovery.
Researchers from the Center for Addiction and Mental Health in Canada used positron emission tomography (PET) to compare levels of translocator protein—a marker for gliosis (brain inflammation), persistent symptoms of depression and cognitive impairment—in 20 participants. 20 healthy controls with symptoms.
The results, published in JAMA Psychiatry, showed that the amount of translocator proteins in the brain regions of interest was higher in participants with depressive and cognitive symptoms compared to controls (17 percent).
The difference was most pronounced in two brain regions: the ventral striatum (22 percent) and the dorsal putamen (20 percent).
“Gliosis may result from inflammation, injury, or both, particularly in the ventral striatum and dorsal putamen, which may explain some of the persistent depressive and cognitive symptoms, including slow motor movements, low motivation or energy, and anhedonia ( decreased ability to experience pleasure),” the researchers said.
In a related comment, Alexander Gerhard of the University of Manchester in the UK said the study was limited by the PET signal, which is not restricted to microglial cells.
“To therapeutically target neuroinflammatory changes, we will need a more detailed understanding of microglial activation at different time points of neurological disorders,” Gerhard wrote.
“Not surprisingly, relatively simplistic attempts to suppress microglial activation have not yet resulted in clinically meaningful results.”