‘Brain fog’ is one of Covid-19’s most daunting symptoms. A new study measures its impact
Of all the lingering symptoms of long Covid, difficulty focusing and thinking, known as brain fog, may be the most frightening and baffling. A new study published Wednesday in the New England Journal of Medicine, which looks at how much cognition is impaired in the months after a coronavirus infection, shows that Covid-19’s impact can be measured in the equivalent of IQ points.
Researchers from Imperial College London found that even people who recovered from their Covid symptoms in four to 12 weeks had the equivalent of an IQ score three points lower than in uninfected people. Among those with long Covid — defined as symptoms lasting more than 12 weeks after testing positive — the drop was six IQ points. For people whose disease was severe enough to require hospital care, the deficit deepened to nine points.
