Since the start of the pandemic, there has been ever-increasing evidence that COVID-19 may have long-term health consequences, as reports came in of people suffering from debilitating effects months after being infected.
Now one of the largest studies of its kind, assessing more than 230,000 people in the US, has found that 1 in 3 COVID-19 survivors received a neurological or psychiatric diagnosis within six months of having the infection, adding to the growing list of "long COVID" consequences.
The findings, published in The Lancet Psychiatry, also confirmed that COVID-19 patients are more likely to suffer from brain conditions compared to patients who suffered from other respiratory tract ailments.
“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," said lead author Professor Paul Harrison, from the Department of Psychiatry at Oxford University, in a statement.
“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.”
The new study looked at electronic health records of 236,379 COVID-19 patients from the US and compared the outcomes with two other cohorts, 105,579 patients diagnosed with influenza (flu) and 236,038 patients diagnosed with any type of respiratory tract infection.
They found that 34 percent of COVID-19 patients were diagnosed with a neurological or psychiatric condition within 6 months of infection. For 13 percent of those patients, it was their first neurological or psychiatric diagnosis. The most common psychiatric conditions were anxiety disorders, followed by mood disorders, substance abuse disorders, and insomnia. Although neurological outcomes were at a lower incidence, brain hemorrhage, ischaemic stroke, and dementia outcomes were reported.
Commenting on the results of the paper, Professor Sir Simon Wessely, Regius Chair of Psychiatry at King’s College London, said: “This is a very important paper. It confirms beyond any reasonable doubt that COVID-19 affects both the brain and mind in equal measure. Some were already known – for example, increased rates of stroke and also anxiety disorders. Others less so – dementia and psychosis for example."
Accounting for age, sex, ethnicity, and existing health conditions, the research also found that COVID-19 patients had a 44 percent increased risk of neurological or psychiatric conditions compared to regular flu.
As this study was an observational investigation, it can't provide insights into what mechanisms may be involved, and as it focused on US cohorts, more work will need to be done to decipher the findings and how they affect people in other countries. Additionally, future investigations should also look into how the risk factors for neurological or psychiatric conditions in those experiencing only mild COVID-19 fare. Nevertheless, the new findings are of great importance.
“Our results indicate that brain diseases and psychiatric disorders are more common after COVID-19 than after flu or other respiratory infections, even when patients are matched for other risk factors," co-author Dr Max Taque concluded. "We now need 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.”
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