People hospitalized with COVID-19 early in the pandemic could suffer health problems and brain confusion for years, with some patients experiencing more severe and new symptoms 12 months later, researchers said.
They found that while many long-term COVID-19 patients’ symptoms improved over time, a significant number still had cognitive problems two to three years later, and symptoms such as depression, anxiety and fatigue worsened rather than subsided.
Scientists studied Long Covid in 475 people who were hospitalised with the virus before a vaccine was available, to see whether symptoms of brain fog, fatigue and mental health issues persisted or emerged beyond a year.
Although the researchers didn’t have information about participants’ thinking abilities before they were infected with COVID-19, cognitive tests two to three years later found that patients’ IQs were, on average, 10 points lower than would be expected for their age, education and other factors. One in nine showed signs of “severe cognitive impairment,” equivalent to an IQ 30 points lower than expected.
Surveys filled out by participants showed that many experienced moderate to severe depression (47%), fatigue (40%) and anxiety (27%) two to three years after COVID-19 infection. Rather than improving over time, symptoms were, on average, worse two to three years after infection than six to 12 months later.
“We knew before we conducted our study that COVID-19 carries a higher risk of cognitive impairment, depression and anxiety compared to other respiratory infections,” said study author Dr Max Tuckett from the University of Oxford. “In our cohort, we found there was a significant neuropsychiatric burden after two to three years.”
More than one in four people surveyed changed jobs after contracting the virus, often because they could no longer cope with the cognitive demands of their work.
Patients whose condition worsened over the years were most likely to be ill six months after infection, but the severity of their original illness did not appear to affect their long-term outcome.
After 6 months, the proportion of patients reporting depression, anxiety, and fatigue increased, but cognitive impairment appeared to have improved: 44% of patients had objective cognitive impairment 6 months after infection, compared with 33% 2 to 3 years later.
This work, The Lancet PsychiatryConsequently, the authors emphasized the importance of early diagnosis and management of long COVID-19 symptoms to reduce the risk of developing more complicated disease.
The number of people with long Covid-19 continues to rise, with two million people now experiencing symptoms in England and Scotland, according to the Office for National Statistics, and a recent study has found that the brain confusion reported by many is equivalent to a six-point drop in IQ.
Danny Altman, a professor of immunology at Imperial College London who was not involved in the research, said the findings were “serious and worrying” and warned against complacency in an era of vaccines and milder COVID-19 variants.
While the risk of long-term illness has fallen from about 10% during the first wave of the coronavirus pandemic to about 2.5% now, that still amounts to a “huge number of cases,” Altman said. “There couldn’t be a more stark warning that COVID-19 is still here and it can still do terrible things, so it’s worth doing the work to prevent infection and avoid reinfection.”
But scientists have urged caution about the results. Only 19% of the 2,500 people invited to take part in the study participated, and the results would be skewed if those who agreed were much worse off or better off than the overall population. It is also unclear whether people who develop long Covid after vaccination in the later stages of the pandemic without being hospitalized will experience serious health problems.
