The lasting mental impacts of severe Covid are similar to 20 years of ageing, researchers have found.
Experts at the University of Cambridge and Imperial College London found that cognitive impairment following severe infection was similar to that sustained between 50 and 70 years of age.
One in seven individuals surveyed reported having symptoms that included cognitive difficulties 12 weeks after a positive test.
Between a third and three-quarters of patients reported still suffering cognitive symptoms three to six months later.
This included the likes of fatigue, brain fog, problems recalling words, sleep disturbances, anxiety and PTSD after infection.
Researchers analysed data from 46 people who received in-hospital care for Covid - 16 of which required mechanical ventilation during their stay.
All of the patients were admitted to Addenbrooke’s Hospital in Cambridge between March and July 2020.
Patients then took cognitive tests an average of six months after their illness, which measures memory, attention and reasoning. Scales measures anxiety, depression and PTSD were also assessed.
Covid survivors were found to be less accurate and had slower response times when compared with 66,008 members of the general public.
And the effects were said to be strongest for those who required mechanical ventilation.
Researchers came to the conclusion that the magnitude of cognitive loss was similar to that sustained with 20 years of ageing - which is the equivalent of losing 10 IQ points.
The patients’ scores and reaction times improved over time, but the researchers say that the recovery in cognitive facilities was at best gradual and likely to be influenced by a number of factors - including illness severity and its neurological and psychological impacts.
It is believed that this decrease in cognitive capabilities may be due to a number of factors - including inadequate oxygen supply to the brain, blockage of large and small blood vessels during clotting and microscopic bleeds.
Emerging evidence suggests that the most important reason may be damage caused by the body’s own inflammatory response and immune system.
While research solely focused on those hospitalised with Covid, the team has suggested that patients not sick enough to be admitted may also have tell-tale signs of mild impairment.
Professor Adam Hampshire, who is the first author of the study, said: “Tens of thousands of 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.
“This means there are 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.”
