Neurodegeneration in older adults is a common and dangerous complication of COVID-19. Mental confusion not only occurs more often in this age group, but it is associated with increased disease severity and death. Experts say that early detection is critical in recovery.

According to Ladders, recent research conducted at St. Thomas Hospital in London found that frail, older adults exhibited a higher prevalence of symptoms of delirium, fatigue, and shortness of breath, and 33% of them did not experience classic symptoms such as fever and coughing. The study authors found such a high correlation between mental confusion and elderly patients that they urged health officials to add delirium to screening guidelines for this age group.

A separate study at Northwestern Medicine in Chicago found that people who exhibit signs of confusion and unresponsiveness have an increased risk of death from COVID-19. According to The New York Times, patients with altered mental function, or encephalopathy, are seven times more likely to die than infected patients with healthy brains.

"Encephalopathy is a generic term meaning something's wrong with the brain," said Dr. Igor Koralnik, senior author of the Northwestern study. Koralnik said that can include lack of attention and concentration, loss of short-term memory, disorientation, unresponsiveness, and a lack of consciousness.