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The study, published in The Lancet Psychiatry journal on Tuesday, analyzed data from the electronic health records of 236,379 Covid-19 patients from the U.S.-based TriNetX network, which includes more than 81 million people.
This group was compared with 105,579 patients diagnosed with influenza and 236,038 patients diagnosed with any respiratory tract infection (including influenza).
Overall, the estimated incidence of being diagnosed with a neurological or mental health disorder following Covid-19 infection was 34%, the study led by researchers at the University of Oxford found when looking at 14 neurological and mental health disorders.
For 13% of these people, it was their first recorded neurological or psychiatric diagnosis.
The most common diagnoses after having the coronavirus were anxiety disorders (occurring in 17% of patients), mood disorders (14%), substance misuse disorders (7%), and insomnia (5%). The incidence of neurological outcomes was lower, including 0.6% for brain hemorrhage, 2.1% for ischemic stroke, and 0.7% for dementia.
After taking into account underlying health characteristics, such as age, sex, ethnicity and existing health conditions, there was overall a 44% greater risk of neurological and mental health diagnoses after Covid-19 than after flu, and a 16% greater risk after Covid-19 than with respiratory tract infections.
Since the coronavirus first emerged in China in late 2019, there have been over 132 million reported cases of the virus and over 2.8 million deaths, according to data from Johns Hopkins University.
Professor Paul Harrison, lead author of the study from the Department of Psychiatry at Oxford University, said the latest study highlights the need for health care systems to be equipped to deal with potentially higher numbers of neurological disorders in survivors of the virus.
“These are real-world data from a large number of patients. They confirm the high rates of psychiatric diagnoses after Covid-19, and show that serious disorders affecting the nervous system (such as stroke and dementia) occur too. While the latter are much rarer, they are significant, especially in those who had severe Covid-19,” he noted.
“Although the individual risks for most disorders are small, the effect across the whole population may be substantial for health and social care systems due to the scale of the pandemic and that many of these conditions are chronic. As a result, health care systems need to be resourced to deal with the anticipated need, both within primary and secondary care services.”
Dr. Max Taquet, a co-author of the study from Oxford University, said further research needed to be done to see “what happens beyond six months.”
“The study cannot reveal the mechanisms involved, but does point to the need for urgent research to identify these, with a view to preventing or treating them.”
Since the pandemic emerged and spread throughout the world in spring 2020, there have been a number of investigations into the short and long-term effects of the virus. The University of Oxford’s Psychiatry department noted that there has been growing concern that survivors might be at increased risk of neurological disorders.
“A previous observational study by the same research group reported that Covid-19 survivors are at increased risk of mood and anxiety disorders in the first three months after infection. However, until now, there have been no large-scale data examining the risks of neurological as well as psychiatric diagnoses in the six months after Covid-19 infection,” the department said.
Read More: 1 in 3 Covid survivors suffer neurological or mental disorders: study