A study published in the Lancet found that patients who had previously tested positive for COVID-19 had lower cognitive accuracy compared to negative controls.
Nearly two years after COVID-19 infection, folks with long COVID symptoms can experience a decline in cognitive function. Though, those who have reported a full recovery from the infection have not experienced this similar decline.
According to a study published in July in The Lancet, authors claimed that it’s unclear whether cognitive deficits following COVID infection improve over time, as previous studies have focused on hospitalized patients with up to a year follow-up.1
To examine cognitive performance based on the effects of COVID-19, researchers monitored participants in the United Kingdom in two rounds: from July 12, 2021, to August 27, 2021 (Round 1), and from April 28, 2022, to June 21, 2022 (Round 2). Participants were gathered through the study’s “COVID Symptom Study,” smartphone app, which included those with and without COVID infection, with varying symptom durations.
Findings revealed that among the participants who completed Round 1 (3,335 participants) and round 2 (2,435), those who had previously tested positive for COVID had lower cognitive accuracy compared to negative controls. This impact was most common in individuals who had experienced symptoms for 12 weeks or more.
The cognitive deficits were similar to the effects of being hospitalized during illness or an age-related decline of 10 years in age. However, participants' self-reported recovery results revealed deficits were found only in positive COVID individuals who did not feel fully recovered, while those who reported complete recovery showed no cognitive deficits.
A longitudinal analysis spanning almost two years since initial infection indicated that cognitive deficits persisted over time for those affected by the virus. However, it was found that there was no evidence of COVID’s impact on average reaction time during tasks, given the role of processing speed in cognitive function.
The effects of long COVID are ‘long lasting,” affecting a massive portion of the population who were infected in 2020. The UK's Office for National Statistics estimated that as of January 2023, approximately 687,000 people in the UK were experiencing self-reported long COVID after an initial infection at least two years prior.
The cognitive deficits resulting to long COVID have the potential to influence both individual quality of life and more broad economic factors due to reduced work capacity and increased support needs, researchers suggested.
This study highlights the need for continued efforts to identify and support those affected by long COVID and cognitive impairment.
It’s suggested future research should focus on understanding recovery time and the functioning of individuals with ongoing symptoms following COVID-19.