Recent research suggests that the virus may cause a significant decrease in brain function and makes it age faster.

In some severe cases, the coronavirus infection has been linked to substantial cognitive decline equivalent to the brain ageing by 10 years among individuals who have recovered from the virus, a non-peer-reviewed study of more than 84,000 people has found. 

The study, led by Adam Hampshire, a doctor at Imperial College London, suggests the cognitive deficits can linger for months. 

The researchers say their conclusion aligns with the view that Covid-19 can trigger chronic cognitive consequences.

“People who had recovered, including those no longer reporting symptoms, exhibited significant cognitive deficits,” the report read.

The researcher group used a study called the Great British Intelligence Test to measure the brain performance of the people who joined the study. Such cognitive tests are also used to spot diseases such as Alzheimer's by giving tasks such as remembering words or asking someone to do a puzzle. All the while, the brain is being tested. The findings, generated by the results, were published online on a website called MedRxiv.

The study suggested that the people who were hospitalised because of the coronavirus had “substantial effect size” deficits.

The findings of the study however may not be entirely consistent or may be lacking, some professors suggest.

Masud Husain, a Professor of Neurology & Cognitive Neuroscience at the University of Oxford, said in a tweet that the study was the strongest evidence for cognitive consequences and their potential impact in long term impacts of Covid-19.

Joanna Wardlaw, a professor of applied neuroimaging at Edinburgh University, says any effects of the virus on cognition may be short term.

The study’s comparison with people hospitalised for other severe viral infections is being planned at the moment, said Hampshire in a tweet. He added that his team looked at depression and anxiety in terms of pre-existing diagnoses among other factors. 

“The cognitive function of the participants was not known pre-COVID, and the results also do not reflect long-term recovery,” she told Reuters.

An August study suggests that approximately 10% of people experience prolonged post-viral illness after recovering from Covid-19.

Derek Hill, a professor of medical imaging science at University College London, also pointed to the lack of data regarding the patient’s pre-Covid scores in the test.

Hill also noted that a large number of people who participated in the study had self-diagnosed, adding that even though the study was intriguing, it was inconclusive.

“As researchers seek to better understand the long term impact of COVID, it will be important to further investigate the extent to which cognition is impacted in the weeks and months after the infection, and whether permanent damage to brain function results in some people,” he told Reuters.

Severe fatigue, respiratory problems, muscle aches, joint pain, memory loss, a lack of concentration, mental health problems, as well as hair loss, are among the symptoms that Covid-19 patients report.