Researchers from the University of Cambridge in England suggest that a severe case of COVID can result in a person losing as many as 10 IQ points. In fact, even in recovered patients, there is evidence that the disease can result in cognitive and mental health issues including brain fog, issues with remembering words, sleeplessness, anxiety, and PTSD.
“Cognitive impairment is common to a wide range of neurological disorders, including dementia, and even routine aging, but the patterns we saw – the cognitive ‘fingerprint’ of COVID-19 – was distinct from all of these,” David Menon, lead author on the study, published in the journal eClinicalMedicine, said in a statement.
1 in 7 people with COVID reported cognitive issues 12 weeks later
A separate study mentioned in the statement suggests that one out of every seven people who caught COVID in the U.K. were reporting cognitive difficulties up to 12 weeks after their initial positive test.
Although mild cases can lead to these symptoms, between 66 and 75 per cent of people hospitalized with COVID are reporting cognitive symptoms three to six months later, another study from Cambridge says.
To examine why COVID was causing a sudden dip in cognitive function, researchers studied 46 people who had been in the hospital, either in a ward or ICU, to treat the infection. Of those 46, 16 required a ventilator during their stay in the hospital. All of them were admitted between March and July of 2020.
Each of the patients later underwent computerized cognitive tests about six months after getting sick, using the Cognitron platform — an online tool that measures aspects of mental acuteness including memory, attention, and reasoning, as well as anxiety, depression and PTSD.
This was the first time that this level of assessment had been performed on COVID-19 patients. The results showed that the subjects of the study were slower and less accurate in testing than the control population, and the same sort of impact was seen at a six-month follow up test. Although researchers did note that some improvement was seen as time passed.
“We followed some patients up as late as ten months after their acute infection, so we were able to see a very slow improvement,” Menon said. “While this was not statistically significant, it is at least heading in the right direction, but it is very possible that some of these individuals will never fully recover.”
When compared against 66,008 members of the general population, the scientists estimated that the COVID patients had cognitive loss similar to 20 years of aging between 50 and 70 years old.
The patients were particularly bad at verbal analogical reasoning, which supports the thought that COVID has an impact on people’s word retention.
Previous studies have shown that there is a possibility of decreased brain glucose, which is essentially fuel for the brain. Since the patients showed slower processing speeds, researchers believe this was observed in their study as well.
And while the research team focused primarily on people who had been hospitalized for the study, they suggest that there are people who were never in the hospital who could still be impaired in similar ways.
“Around 40,000 people have been through intensive care with COVID-19 in England alone and many more will have been very sick, but not admitted to hospital,” Adam Hampshire, author of the study, said. “This means there is a large number of people out there still experiencing problems with cognition many months later. We urgently need to look at what can be done to help these people.”
In Canada, 3.7 million people have had COVID-19, and 39,000 have died, according to the federal government.
Chris Arnold is a Toronto-based writer.