Researchers at Oxford University report that more than half of individuals who experience long-term Covid-19 show signs of lasting cognitive decline. The findings, published in EClinical Medicine, add to a growing body of evidence about persistent brain effects after infection (Source: Oxford University).
Long-term Covid-19 is defined as symptoms that endure beyond 12 weeks following a coronavirus infection. These persistent complaints can include fatigue, apathy, mental fog, headaches, a lingering cough, and chest discomfort. The duration of what is sometimes labeled as post-Covid syndrome varies from person to person, and its trajectory remains uncertain as more data are gathered (Source: study authors).
The investigation involved 194 participants, with 119 diagnosed with long-term Covid and 75 healthy volunteers serving as controls. Each participant completed two cognitive assessments, including a simple reaction time (SRT) test. This test requires a person to press the space bar in response to visual prompts on a monitor, and it measures how quickly and accurately basic cognitive processes are engaged.
Compared with healthy controls, individuals with long-term Covid exhibited a reaction time that was about 0.49 seconds slower on average. Those with persistent post-Covid symptoms also performed worse on cognitive tests assessing attention and processing speed. Moreover, a subset of long-term Covid patients with lower SRT performance reported accompanying declines in mental health, sleep quality, and mood, while some long-haulers noted increased fatigue after completing the assessments (Source: study authors).
The study also highlighted that those who had Covid-19 but did not develop long-term, negative bodily effects did not show impairments in the SRT measure, suggesting a specific association between prolonged post-infection symptoms and certain cognitive changes (Source: study authors).
Estimations from the authors indicate that cognitive decline was present in about 53% of the long-term Covid group. The data did not demonstrate an improvement in cognitive performance over the study period. The precise mechanisms driving these cognitive changes remain unclear, underscoring the need for further research. Future work should include larger, more diverse cohorts and comprehensive neuropsychological assessments to better characterize the scope and progression of cognitive effects following long-term Covid (Source: study authors).
In past discussions, there has been mention of nutritional supplements that might support recovery in some long-haulers, though such claims require rigorous evaluation within clinical contexts to determine their efficacy and safety (Source: study context).