COVID-19 has proven that it can affect almost any part of the body, including the brain. A study of 1.28 million people who had the disease, published August 17 in Lancet Psychiatrysheds light on the often complex and sometimes long-term impacts of COVID-19 on the minds of children and adults.
Analyzing data from patients in the U.S. and several other countries, researchers found that in the first two months after contracting COVID-19, people were more likely to experience anxiety and depression than people who contracted a different type of respiratory infection. And for up to two years afterwards, people remain at greater risk of conditions such as brain fog, psychosis, seizures and dementia.
Prolonged COVID—marked by at least one symptom that persists for months after COVID-19—is a growing problem worldwide. Earlier research from the US Centers for Disease Control and Prevention (CDC) estimates that approximately one in five people in the US who get COVID-19 develop it. This week’s study helps researchers better understand the manifestations of Long COVID.
The results “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 to treat them when they do occur,” said lead author Maxime Take. of Research and Senior Research Fellow at the University of Oxford, in a statement.
The researchers found that the risks of poor neurological or psychiatric outcomes after infection with Delta were higher than the risks after infection with the original variant—and about the same as the risks after Omicron. Effects also vary by age group. Older people age 65 and older who had COVID-19 had brain fog, dementia, and psychotic disorders at higher rates than adults of the same age who had other respiratory infections.
Among patients with COVID-19 in this age group, 450 cases of dementia were found per 10,000 people, compared with 330 cases per 10,000 people who had other respiratory infections. Brain fog also occurred at a higher rate: there were 1,540 cases per 10,000 people infected with COVID-19, compared to 1,230 cases per 10,000 people with other infections.
The results were less dramatic for the younger groups. There was little difference in the risk of dementia for people 64 and younger who had either COVID-19 or another respiratory infection. For brain fog, there were 640 cases per 10,000 people with COVID-19, compared to 550 cases per 10,000 people with various respiratory infections.
Although children had a lower overall risk of poor brain outcomes than adults, they were still twice as likely to develop epilepsy or seizures within two years of contracting COVID-19 (260 cases per 10,000 ) compared to children who had other respiratory infections. And while the risk of children being diagnosed with a psychotic disorder remains low, the study authors saw an increase among children with COVID-19 (18 per 10,000) compared to children who had other respiratory infections (6.3 per 10,000).
Meanwhile, the risk of anxiety and depression was no greater for children who had COVID-19 than for those who had other respiratory infections. Although mood and anxiety disorders were shown to peak during SARS-CoV-2 infections, these risks returned to baseline after two months, after which the risk of anxiety and depression actually decreased among all ages studied.
“The good news is that the over-diagnosis of depression and anxiety following COVID-19 is short-lived and that it is not seen in children,” said study author Paul Harrison, professor in Oxford’s Department of Psychiatry, in statement. “Worryingly, however, some other diseases, such as dementia and seizures, continue to be more likely to be diagnosed after COVID-19, even two years later.”
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