Study Details
The research, led by Professor Adam Hampshire, analyzed data from over 112,000 volunteers who underwent Covid tests during the pandemic. The participants were categorized based on the severity of their Covid-19 infection, ranging from those who avoided the disease entirely to individuals who required intensive care due to severe illness. The analysis revealed a clear correlation between the severity of Covid-19 infection and cognitive decline:
- Severe Infections: Individuals admitted to intensive care with Covid-19 scored approximately nine IQ points lower on average in cognitive exams compared to those who avoided infection altogether.
- Long Covid: Participants reporting persistent symptoms such as ‘brain fog’ scored six points lower on IQ tests.
- Mild Infections: Even individuals with mild Covid-19 infections experienced a decline in cognitive abilities, scoring two points lower on average in IQ tests.
Long-Term Cognitive Impacts
Further examination of the data suggested that the cognitive impacts of Covid-19 could be long-lasting, with some individuals experiencing declines in cognitive abilities even a year or more after infection. Interestingly, the study found that the original Covid strain was associated with a more significant drop in IQ compared to the Omicron variant. Additionally, vaccination appeared to have a protective effect against cognitive decline, highlighting the importance of vaccination efforts in combating the long-term effects of the virus.
Interpretation and Caution
While the study provides valuable insights into the cognitive effects of Covid-19, Professor Hampshire and his team urge caution in interpreting the results. The study did not compare the cognitive abilities of individuals before and after infection, which limits the ability to establish causality definitively. However, the findings underscore the need for further research into the long-term consequences of Covid-19 on cognitive health.
“Participants with resolved persistent symptoms after Covid-19 had objectively measured cognitive function similar to that in participants with shorter-duration symptoms, although short-duration Covid-19 was still associated with small cognitive deficits after recovery. Longer-term persistence of cognitive deficits and any clinical implications remain uncertain.”
Cited from the report by Professor Hampshire and his team on a large-sample research.
Insights From Field Experts
Professor Benedict Michael, director of the University of Liverpool’s infection neuroscience laboratory, acknowledged the existence of a severely affected group but expressed skepticism regarding widespread cognitive declines across the population. He highlighted the need for more evidence to support claims of widespread cognitive impacts.
“Clearly a very severely affected group, (but) I haven’t yet seen convincing evidence that the vast majority of the population have been knocked back by X number of IQ points.”
Professor Benedict Michael added.
Brain Fog and Blood Brain Barrier Damage
The study’s findings align with emerging research linking long Covid symptoms, such as brain fog, to underlying biological changes in the brain. MRI scans revealed signs of damaged blood vessels in the brains of individuals experiencing brain fog, suggesting a potential link between leaky blood brain barriers and cognitive symptoms associated with long Covid.
This Won’t Be The Last We Hear From Covid-19
While the immediate health impacts of Covid-19 have been widely documented, the long-term effects on cognitive health are only beginning to be understood. The study underscores the importance of continued research into the neurological consequences of Covid-19 and highlights the need for comprehensive strategies to mitigate the long-term cognitive effects of the virus.
As scientists continue to unravel the complexities of Covid-19, addressing the cognitive impacts of the virus remains a crucial aspect of public health efforts worldwide. Through ongoing research and vigilance, healthcare professionals can better understand, mitigate, and ultimately prevent the long-term cognitive consequences of Covid-19.
