While the long-term effects of COVID-19 are still unknown, a recent study showed that those who had severe cases of the virus and now suffer from cognitive impairment have lost the equivalent of 10 IQ points.
Researchers at the University of Cambridge and Imperial College London looked at 46 patients for six to 10 months after they had been hospitalized due to severe cases of the disease, and published their findings in the journal eClinicalMedicine.
The study also compared the cognitive impairment caused by a severe case of COVID-19 "to the effects of aging between 50 and 70 years of age."
This study comes as patients that have recovered from the virus have reported a number of lingering symptoms, including "brain fog" or cognitive difficulties, "problems finding the words," and sleep disturbances, among other psychiatric disorders.
"In the UK alone, 13.7% of 20,000 individuals reported having symptoms inclusive of cognitive difficulties 12 weeks after a positive COVID-19 test (UK Office for National Statistics, April 2021)," the study said.
"Mild cases can report persistent cognitive symptoms; however, prevalence is higher in severe cases, with ∼33–76% of patients suffering cognitive symptoms 3–6 months post hospitalisation."
The patients in the study went through a series of computerized cognitive tests that measured their memory, attention and reasoning, in addition to measuring anxiety, depression, and post-traumatic stress disorder (PTSD).
The results were compared to 66,008 people from the general public, and showed that those who suffered from severe COVID-19 "were less accurate and with slower response times than the matched control population." The findings also said the cognitive effects on people that had to be put on a ventilator were the most severe.
"Cognitive impairment is common to a wide range of neurological disorders, including dementia, and even routine ageing, but the patterns we saw – the cognitive 'fingerprint' of COVID-19 – was distinct from all of these," the study's lead author, Professor David Menon from the Division of Anaesthesia at the University of Cambridge, said in a statement.
Menon went on to say that the study continued to follow up with patients up to 10 months after they had the virus, and indicated there was cognitive improvements in some people, but not everyone.
"We followed some patients up as late as ten months after their acute infection, so 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."
Professor Adam Hampshire from the Department of Brain Sciences at Imperial College London, the study's first author, said in the statement that there needs to be something done to help those people dealing with cognitive effects from COVID-19. He suggested that there are likely even more people suffering than the study indicated, but they were lucky enough to avoid hospitalization.
"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," Hampshire 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."