Covid linked to longer-term elevated risk of brain fog and dementia

Millions of people who have had Covid-19 still face a higher risk of neurological and psychiatric conditions, two years after their illness, compared with those who have had other respiratory infections.

Within two months of having Covid-19, the risk of anxiety and depression disappears. The risk is not likely to go up over the next two years. The findings can be found in the journal.

Almost 600m Covid-19 cases have been recorded worldwide since the start of the Pandemic, and there has been growing evidence that people who survive the disease face increased risks.

People are more likely to suffer from neurological and mental health conditions in the first six months after an infectious disease. There has been no large-scale data looking at the risks for a long time. 1.28m Covid-19 cases were analysed by the University of Oxford and the National Institute for Health and Care Research.

The findings shed new light on the long-term mental and brain health consequences of Covid-19 infections. The results show 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 study looked at diagnoses from health records in the US. The risk of depression or anxiety in adults increased after Covid-19 but returned to normal within two months.

The risk of other neurological and mental health conditions remained higher after Covid-19 than at the end of the two year follow-up.

Adults under the age of 64 who had Covid-19 had a higher risk of brain fog than adults who had other respiratory infections.

There was a higher incidence of brain fog, dementia, and psychotic disorders in people who had Covid-19 than in people who had a different respiratory illness.

Children and adults had similar results. Children who had other respiratory infections were not at higher risk of anxiety or depression than children who had Covid-19. Children recovering from Covid-19 are more likely to be diagnosed with a variety of conditions.

Neurological and psychiatric disorders were more common during the Delta variant wave. The Omicron wave had the same risks as Delta.

There were some important limitations that the researchers warned against. There are unlikely to be recorded cases of Covid-19 that are self-diagnosed. The severity and length of conditions after Covid-19 were not looked at.

It is good news that the excess of depression and anxiety diagnoses after Covid-19 is not observed in children. Some disorders, such as dementia and seizures, are more likely to be diagnosed after Covid-19.