COVID-19 linked to “significant” drop in intelligence: research

TORONTO – People who recovered from COVID-19, including those who no longer had symptoms, had significant ‘cognitive deficits’, large UK study finds

The research, conducted by academics from Imperial College London, Kings College and the universities of Cambridge, Southampton and Chicago, aimed to find out how COVID-19 is affecting mental health and cognition.

For the study, the researchers analyzed data from 81,337 participants from the Great British Intelligence Test from January to December 2020. Among these participants, nearly 13,000 declared having contracted the new coronavirus.

Importantly, the study indicated that only 275 participants completed the intelligence test before and after contracting COVID-19.

For the rest of the participants, the researchers said they used a linear model to predict general cognitive performance, or premorbid intelligence, based on age (third order), sex, laterality, ethnic origin, mother tongue, country of residence, professional status. , and earnings.

“Predicted and observed overall performance was strongly correlated, providing an indirect measure of premorbid intelligence performance comparable to common explicit tests such as the National Adult Reading Test,” the study said.

What’s more, academics also found that their intelligence estimates for individuals before the disease indicated that those who contracted COVID-19 were in fact likely to have had “somewhat higher than lower cognitive ability” before. to be sick.

After controlling for these factors, they found that those who had COVID-19 underperformed compared to those who had never contracted the disease.

Cognitive deficits were particularly pronounced for testing tasks that involved reasoning, problem solving, spatial planning, and target detection, while those with COVID-19 fared better when asked to ” perform simpler tasks, such as working memory and emotional processing.

“These findings are consistent with long-standing reports of COVID, where ‘brain fog’, problems with concentration, and difficulty finding the correct words are common,” the authors noted. “Recovery from a COVID-19 infection may be associated with particularly pronounced problems in aspects of higher cognitive or ‘executive’ function. “

The authors said their results appear to show that COVID-19 infection is associated with cognitive deficits that can persist until the recovery phase, such as in long COVID cases in which symptoms can last for weeks or so. months after the initial illness.

The level of underperformance also depended on the severity of the disease in the group that had COVID-19 during the pandemic. The study said those who had been placed on a ventilator during the pandemic had the greatest cognitive deficits, so much so that it was equivalent to a seven-point drop in IQ in a classic intelligence test.

The decline in intelligence in those who had been ventilated was also greater than the deficits seen in patients who had previously had a stroke or reported learning disabilities, according to the document.

The authors cautioned against drawing definitive conclusions on the neurobiological or psychological basis of intelligence deficits without brain imaging data; However, they said the findings should serve as a call for further research on the topic.

The study, “Cognitive deficits in people who have recovered from COVID-19, ”Was published in The Lancet newspaper last week.