The long-term effects of Covid-19 infection may include decreased intelligence, according to new research.
Between January and December last year, scientists conducted the Great British Intelligence Test, which examined the IQ of 81,337 people. Among them there were 13,000 people infected with the virus.
After taking into account factors such as age, gender, language, and educational level, they found that people who recovered from Covid experienced the largest decrease in intelligence.
Tasks requiring problem solving, planning and reasoning were more difficult for them than for people who were not infected with the virus.
In the most severe cases, when people were on a ventilator to defeat the disease, the researchers recorded a drop in intelligence by seven points.
The findings were compiled and published in a study titled: Cognitive Deficits In People Who Have Recovered From COVID-19 '.
It was published in the medical journal The Lancet and brought together researchers from Imperial College London, King's College and the universities of Cambridge, Southampton and Chicago.
These results are consistent with reports of long-term Covid history, where "brain fog", trouble concentrating, and difficulty finding the right words are common, "the authors write.
"In people who have been hospitalized, these deficiencies have had a significant effect."
Scientists speculate that one of the reasons for the decline in intelligence is the continuing impact of the virus on a person's ability to think clearly.
"Previous studies in hospitalized patients with respiratory diseases not only demonstrate objective and subjective cognitive impairments, but also indicate that they persist in some of them for 5 years," the authors note.