People who’ve had COVID are at a higher risk of developing neurological and psychiatric conditions like psychosis, dementia and brain fog for up to two years after infection — compared to those who’ve had other respiratory illnesses, new research suggests.
Adults are also at increased risk for anxiety and depression, but this decreases within two months of their illness, researchers found.
The study of 1.25 million people diagnosed coronavirus also found that children are more likely to be diagnosed with certain conditions, such as seizures and psychotic disorders.
However, the probability of most diagnoses after having COVID-19 was lower than in adults.
The study analyzed data on 14 neurological and psychiatric diagnoses collected from electronic health records, mostly from the US, over a two-year period.
It found that in adults, the risk of depression or anxiety increased after COVID-19, but was back to the same as with other respiratory infections within about two months.
However, the risk of being diagnosed with a number of other neurological and mental health conditions remained higher after coronavirus than for other respiratory infections at the end of the two-year follow-up.
Adults 64 and younger had a higher risk of brain fog and muscle disease, compared with those who had other respiratory infections.
In adults 65 years of age and older who have a COVID there were more brain fog (1,540 cases per 10,000 people), dementia (450 cases per 10,000 people) and psychotic disorders (85 cases per 10,000 people) compared to those who previously had another respiratory infection.
Researchers found that the Delta variant was associated with more disorders than the Alpha, and Omicron with similar neurological and psychiatric risks as Delta.
Professor Paul Harrison, from the University of Oxford and lead author of the study published in The Lancet Psychiatry, said that while the numbers are not trivial, they are not huge and should be compared with the increasing burden of brain and mental health problems that can be caused by the pandemic has occurred across the population.
He said: “In addition to confirming previous findings that COVID-19 may increase the risk of some neurological and psychiatric disorders in the first six months after infection, this study suggests that some of these increased risks may persist for at least two years.
“The results have important implications for patients and health services as it suggests that new cases of neurological disorders related to COVID-19 infection are likely to emerge well after the pandemic has subsided.
“Our work also highlights the need for more research to understand why this happens after COVID-19 and what can be done to prevent or treat these conditions.”