COVID-19 increases risk of brain fog and dementia

People recovering from COVID-19 suffer from increased rates of brain fog and dementia, according to the largest study of its kind, which was published on Thursday.

The research suggests such neurological and psychiatric conditions remain more common for as long as two years after a COVID-19 infection, compared with other respiratory infections.

Researchers also found an increased risk of anxiety and depression, but noted that this subsides to rates in line with other respiratory diseases within two months of contracting COVID-19.

The study, published in The Lancet Psychiatry journal, analyzed data on 14 neurological and psychiatric diagnoses gathered from more than a million patient health records, mostly in the United States, during a two-year period, reported Sky News.

Max Taquet of the department of psychiatry at the University of Oxford, one of the study authors, said the finding that the excess risk of depression and anxiety disorders disappeared within two months was "very reassuring indeed". Speaking during a news briefing, he said: "The more worrying news is that other disorders including brain fog, dementia, psychotic disorders, and epilepsy and seizures remain elevated, with more new cases still being newly diagnosed two years after COVID-19 infection."

The researchers cautioned that the study also likely under-represented people with mild or asymptomatic COVID-19, and in some cases vaccination status may have been unrecorded.

The study sought "to pull out what COVID, as the virus, does to you specifically, versus what other viruses affecting the same part of your body in a generally similar fashion might be doing," said lead author Paul Harrison. "The results have important implications for patients and health services as it suggests new cases of neurological conditions linked to COVID-19 infection are likely to occur for a considerable time after the pandemic has subsided."

The study's results add to a growing body of research identifying long-lasting damage caused by the novel coronavirus. Such symptoms, known as "long COVID," include both neurological problems as well as fatigue and shortness of breath.

Taquet said: "The findings shed new light on the longer-term mental and brain health consequences for people following COVID-19 infection. The results have implications for patients and health services and highlight the need for more research to understand why this happens after COVID-19, and what can be done to prevent these disorders from occurring, or treat them when they do."

The World Health Organization said it is estimated that 3.7 percent of COVID-19 patients develop a post-COVID symptom. It says the average severity of post-COVID conditions are equivalent to those experienced by patients with severe neck pain, or the long-term consequences of traumatic brain injury.