Those who have recovered from Covid-19 may have a mental decline equivalent to brain ageing by 10 years, a new study has shown.
The non-peer-reviewed study, which was conducted on 84,285 people, showed a link between Covid-19 infection and significant cognitive deficits for months.
“Our analysis … align with the view that there are chronic cognitive consequences of having Covid-19. People who had recovered, including those no longer reporting symptoms, exhibited significant cognitive deficits,” reads the research led by Adam Hampshire, a doctor at Imperial College in London.
The conclusion was made after the 84,285 people completed the Great British Intelligence Test.
The findings, which were published online on the MedRxiv website, show that the cognitive deficits were “of substantial effect size” especially those who had been hospitalized with Covid-19.
Some of those people showed effects “equivalent to the average 10-year decline in global performance between the ages of 20 to 70”.
Scientists not involved in the study have criticized the validity of the study.
“The cognitive function of the participants was not known pre-Covid, and the results also do not reflect long-term recovery – so any effects on cognition may be short-term,” Joanna Wardlaw a professor of applied neuroimaging at Edinburgh University.
A professor of medical imaging science at University College London, Derek Hill said the findings are not completely reliable because they did not compare the before and after scores. Derek also claimed a large number of people self-reported with Covid-19.
“Overall this is an intriguing but inconclusive piece of research into the effect of Covid on the brain,” Derek noted.
“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,” Derek added.