More than three years since the COVID-19 pandemic's onset, new research is still aiming to answer questions about the infection's long-term effects. For example, what is its impact on the brain, our thinking and memory skills?
That's the question researchers at King's College London sought to answer in a recent study published Friday. And their answer: Long COVID "brain fog" is comparable to aging 10 years.
To come to this conclusion, the team studied groups of people in the United Kingdom COVID Symptom Study Biobank, all with varying degrees of symptoms and some without the illness. There were 3,335 individuals in the study's first round, and 1,768 went on to complete a second round.
Each participant underwent 12 cognitive tests to measure speed and accuracy, including working memory, attention, reasoning and motor control.
In both rounds, researchers found cognitive deficits were highest in those with 12 weeks or more of symptoms, and the deficits were still detectable nearly two years after the infection. Those with symptoms showed no signs of cognitive recovery in the nine months between the first and second rounds.
These cognitive impairments were only detectable in participants who still felt long COVID symptoms; no deficits were found in those who felt fully recovered.
As COVID health emergency ends, long haulers fear being forgotten
The CDC estimates 1 in 5 Americans who have had COVID have at least one lingering symptom. One woman shares how her life has changed with long COVID.
The study states that whether these deficits from a COVID infection improve over time is unclear, as the persistence of these effects "remain relatively unexplored."
But it compared those with deficits to "an increase in age of approximately 10 years, or exhibiting mild or moderate symptoms of psychological distress." However, this cognitive decline was less severe than other symptoms or factors, like high levels of fatigue or lower educational attainment.
"The scale of deficits we observed may have detrimental impacts on quality-of-life and daily functioning at an individual level as previously reported, as well as socio-economic impacts on society more broadly due to both a reduced capacity to work and an increased need for support," lead author Dr. Nathan Cheetham said.
Census data from February states 2 million U.K. residents self-reported long COVID symptoms, meaning they last more than four weeks since the start of the infection. And January data from the CDC says 11% of people who have had COVID report long COVID symptoms.
Doctors are still hunting for the cause of long COVID brain fog, but there has been progress in how its symptoms can be identified, with hope more specific treatment is next in line for research.
