Covid-19 could damage people’s IQ by 8.5 points

Mental decline equivalent to brain ageing 10 years in worst cases

• 

  A view of St. Nicolas street with its restaurants closed in Pamplona, northern Spain. Regional authorities ruled that restaurants must be closed for 14 days. EPA

• 

  People queue at a Covid-19 test center at the airport in Frankfurt, Germany. AP Photo

• 

  Dancer Ayami Miyata wears a face covering during a training class ahead of Northern Ballet's first live performances in more than seven months, in Leeds, England. AP Photo

• 

  Two cleaning workers disinfect the streets of Ourense, in Galicia, northwestern Spain. EPA

• 

  People wearing face masks walk past the Colosseum in Rome, Italy. Reuters

• 

  Members of the Czech Army set up equipment and beds inside of field hospital built in an exhibition center in Prague, Czech Republic. Getty Images

• 

  A man wearing a protective face mask works out in a gym in Rome, Italy. Reuters

• 

  Two women wearing face masks to protect against coronavirus walk along a bridge near a Stalin-era skyscraper in central Moscow, Russia. AFP

The IQs of people worst affected by Covid-19 plummeted by 8.5 points and their mental decline was equivalent to the brain ageing by 10 years, a research study indicates.

Researchers said their findings backed up evidence that the virus has consequences for cognitive function that persist into the recovery phase. Those who were admitted to hospital with Covid-19 were hit particularly hard.

The team analysed results from 84,285 people who took part in a study called the Great British Intelligence Test. The research has not yet been peer-reviewed.

“At a finer grain, the deficits were broad, affecting multiple cognitive domains,” the researchers wrote.

“They also were more pronounced for tests that assessed semantic problem solving and visual selective attention while sparing tests of simpler functions such as emotional processing and working-memory span.”

Neuroscientist Dr Adam Hampshire from Imperial College London said an important aspect to understand in the future was the duration of symptoms.

“What we can see in the results is that people who suspected they had Covid-19 performed less well than we would expect,” he told the BBC.

"This underperformance is greater for people who were more ill, particularly those who went to hospital, ended up in critical care or on a ventilator. It’s also greater for people who actually had a biological test, so who we know were definitely unwell with Covid-19,” said Dr Hampshire, lead author of the study.

Cognitive tests measure how well the brain performs tasks – such as remembering words or joining dots on a puzzle. Such tests are widely used to assess brain performance in diseases such as Alzheimer’s and can also help doctors assess temporary brain impairment.

The research was carried out by a team from Imperial College London, the University of Cambridge, King’s College London and the University of Chicago.

• 

  Visitors wearing protective masks ride on a roller coaster at Ocean Park during the theme park's reopening in Hong Kong, China. Bloomberg

• 

  Health workers get a blood sample from a newborn through a makeshift window on the COVID-19 isolation area in Manila, Philippines. REUTERS

• 

  Visitors pose for photographs at Antony Gormley's 'Angel of the North' in Gateshead, northeast England. AFP

• 

  Health workers wearing protective jumpsuits carry the body of a 62-year-old displaced Syrian man who died from Covid-19 in Salqin, in the northwestern Syrian Idlib province. AFP

• 

  People pass a coronavirus-themed mural in Medan, North Sumatra, Indonesia. AP Photo

• 

  A young woman wearing a face mask walks across the medieval Charles Bridge in Prague, Czech Republic. AP Photo

• 

  Government health workers check the temperature of a man at a Murutipucu River riverside community in Igarape-Miri, Baixo Tocantins, Para state, Brazil. AFP

• 

  Empty chairs sit under parasols on a beach in Legian, Bali, Indonesia. Bloomberg

• 

  Students sit at a distance as a precaution against COVID-19, as they undergo an aptitude test to access the University of Medicine, in Rome. AP Photo

• 

  A healthcare working in protective gear works at a COVID-19 testing facility in Melbourne, Victoria. EPA

• 

  An employee chats with a resident who had been infected with the new coronavirus at a nursing home in Santiago, Chile. AP Photo

But shortcomings of the study were the failure to compare “before and after” scores and the inclusion of those who suspected they had the virus, but had not officially tested positive. One expert not involved in the study said its findings should be interpreted with caution.

“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,” said Joanna Wardlaw, a professor of applied neuroimaging at Edinburgh University.

Researchers previously warned that “long Covid” may not be one syndrome but as many as four, causing a roller coaster of symptoms affecting all parts of the body and mind.

At Oxford University, one study found that many patients discharged from hospital still experience symptoms of breathlessness, fatigue, anxiety and depression two to three months after contracting the virus.

The scientists also detected abnormalities in multiple organs and believe persistent inflammation may be a factor for Covid-19 survivors.