Covid-19 is more likely than other respiratory infections to lead to conditions such as psychosis, dementia, brain fog and seizures for up to two years after contraction, a study of more than 1.25 million people has found.
The research also found there is an increased risk of anxiety and depression in adults, but this subsides within two months of infection.
For children infected with Covid-19, the study suggested they were more susceptible to some conditions such as seizures and psychotic disorders, although the likelihood of most diagnoses after infection was lower than in adults.
Covid-19 variants were assessed, too, and the Delta variant was associated with more disorders than the previous Alpha variant. Omicron's neurological and psychiatric risks were similar to Delta's.
The study involved 185,748 children (aged under 18 years), 856,588 adults between 18 and 64, and 242,101 adults over 65. They were matched to an equal number of patients with another respiratory infection to act as a control group.
Records from Covid-19 patients infected during different pandemic waves were compared to investigate differences in the impact of the Alpha, Delta and Omicron variants on the risk of neurological and psychiatric diagnoses.
“The results have important implications for patients and health services as it suggests new cases of neurological conditions linked to [Covid-19] are likely to occur for a considerable time after the pandemic has subsided,” said study lead author Prof Paul Harrison from the University of Oxford.
“Our work also highlights the need for more research to understand why this happens after [infection], and what can be done to prevent or treat these conditions.”
The research team did note that their study had a number of limitations, with uncertainty over when disorders began, how severe they were, or how long they lasted.
In addition, the vaccination status of every case studied was not always clear, and those with mild Covid-19 infections were probably underrepresented in the data.
