Researchers have found that people diagnosed with Covid-19 have higher risk of developing some mental disorders, such as psychosis, seizures or epilepsy, brain fog, and dementia.
The study, led by Maxime Taquet, a Senior Fellow at Taquet at the Oxford Biomedical Research Centre, also found that adults have an increased risk of developing mental disorders after Covid-19 than children.
These are the latest in the long line of research findings on the effects of Covid-19 and mental health. It is long established that Covid-19, particularly Long Covid, affects a person's mental health.
Here we explain the findings of the Lancet's recently-published study, its significance, and the existing understanding of Long Covid.
Findings a mix of good and bad news
The Lancet Psychiatry study examined electronic health records of about 1.25 million people diagnosed with Covid-19 and tracked the occurrence of 14 major neurological and psychiatric diagnoses in these patients for up to two years, according to Paul Harrison, one of the authors of the study. They examined children, adults (18-65), and older adults (over 65) separately.
Harrison described the findings as "a mixture of good and bad news" in an article in The Conversation.
The good news
First mentioning the good news, Harrison wrote that although they observed a greater risk of anxiety and depression after Covid-19 infections, rates of these disorders among people who had Covid-19 were no different than those who had other respiratory infections. This means that Covid-19 does not case an increase in anxiety and depression.
"It was also good news that children were not at greater risk of these disorders at any stage after Covid infection. We also found that people who had had Covid were not at higher risk of getting Parkinson’s disease, which had been a concern early in the pandemic," noted Harrisson, a professor of psychiatry at University of Oxford.
The bad news
However, other findings are indeed worrying, suggesting an increase in serious mental disorders.
The risk of developing psychosis, seizures or epilepsy, brain fog, and dementia remained high for people who had Covid-19. Harrison noted that the risk of dementia in older adults was 4.5 per cent in the two years after Covid-19 compared with 3.3 per cent in those with another respiratory infection.
"We also saw an ongoing risk of psychosis and seizures in children," noted Harrison.
The researchers further noted that the risks were same across variants, meaning that the lesser serious variant or coronavirus could also cause the same mental effects as a severe variant such as Delta.
"The fact that neurological and psychiatric outcomes were similar during the delta and omicron waves indicates that the burden on the health-care system might continue even with variants that are less severe in other respects," noted researchers in their study.
Covid-19 and cognitive decline
Covid-19 has long been associated with mental health issues, particularly with cognitive decline.
Cognitive decline is a major feature of Long Covid, with "brain fog" being its main feature. Brain fog is an umbrella term used to describe a certain conditions marking cognitive decline after contracting Covid-19.
Healthline lists the following conditions of brain fog:
- memory problems
- lack of mental clarity
- poor concentration
- feeling “out of it”
An earlier study found that people hospitalised due to severe Covid-19 can experience cognitive decline that they would otherwise experience in 20 years of ageing. The study, published in the eClinicalMedicine journal, found tha brain damage caused by Covid-19 —found in another study— could be behind this cognitive decline.
Significance of research findings
The findings add to the current understanding of Covid-19 and its effect on mental health. It reinforces the need of a holistic approach to treat and Covid-19 management.
The study highlights the importance to bring mental health experts too in the folds of Covid-19, as the resolution of physical symptoms such as cough, cold, or breathing issues is just one step of the process. The complete recovery would also include the recovery of mind from mental effects of Covid-19.
"Our findings are relevant to understanding individual-level and population-level risks of neurological and psychiatric disorders after SARS-CoV-2 infection and can help inform our responses to them," note the researchers in their Lancet paper.
Existing research on Covid and mental health
Despite highlighting the importance of their findings, Harrison also noted its limitations. He said that the study is only observational, which means they can only tell "what" happens and not "how" it happens. Therefore, their findings cannot tell the reason behind the increased or not-so-increased risk of certain mental health conditions after Covid-19.
"And we cannot fully account for the effect of vaccination, because we didn’t have complete information about vaccination status, and some people in our study caught Covid before vaccines became available," noted Harrison.
However, pre-existing research has answers to these questions. The eClinicalMedicine journal study, cited above, noted that brain damage caused by Covid-19 could be a reason for cognitive decline.
"Direct viral infection is possible, but unlikely to be a major cause. Instead, it is more likely that a combination of factors contributes, including inadequate oxygen or blood supply to the brain, blockage of large or small blood vessels because of clotting, and microscopic bleeds," said Adam Hampshire of Imperial College London and David Menon of University of Cambridge in an article.
Hampshire is the lead researcher of the eClinicalMedicine journal study and Menon is a senior author.
As for vaccination's effects, New York University health expert Leora Horwitz said since Long Covid is more likely with severe Covid and since vaccines prevent severe Covid, vaccinations are likely to prevent Long Covid too.
"You're more likely to have long Covid with more severe disease, and we have ample evidence that vaccination reduces the severity of disease. We also now have quite a lot of evidence that vaccination does reduce your risk of Long Covid – probably because it reduces your risk of severe disease," said Horwitz, a professor of population health and medicine, to Medical News Today.