COVID-19's Profound Impact on Brain Health: New Studies Highlight Cognitive Decline and Brain Fog

Since the early days of the pandemic, COVID-19 has been linked to a concerning health condition known as "brain fog." This colloquial term describes a state of mental sluggishness and lack of clarity, making it challenging for individuals to concentrate, remember things, and think clearly. Now, after four years of the pandemic, research has unveiled significant evidence that COVID-19 can have various adverse effects on brain health.

Uncovering the Impact

Dr. Ziyad Al-Aly, chief of research and development at VA St. Louis Health Care System, has been dedicated to studying long COVID and its effects on the brain. Numerous studies have highlighted the ways in which COVID-19 can impact brain health, including:

• Increased risk of cognitive deficits, such as memory problems, in individuals who had COVID-19.
• Shrinkage of brain volume and altered brain structure observed in imaging studies of individuals before and after COVID-19 infections.
• Prolonged inflammation of the brain and changes equivalent to seven years of brain aging in people with mild to moderate COVID-19.
• Cognitive deficits and brain damage equivalent to 20 years of aging in individuals with severe COVID-19 requiring hospitalization or intensive care.
• Fusion of brain cells triggered by SARS-CoV-2 infection in laboratory experiments, leading to compromised brain function.
• Persistence of the virus in brain tissue, as indicated by autopsy studies, suggesting that SARS-CoV-2 can enter the brain in some individuals.
• Provocation of brain inflammation and impairment of brain cell regeneration, even in cases where the virus is mild and confined to the lungs.
• Disruption of the blood-brain barrier, making it "leaky" and leaving the nervous system vulnerable.
• Increased risk of new-onset dementia in people older than 60 years of age, as indicated by a preliminary analysis of almost 1 million individuals with COVID-19.

Drops in IQ

A recent study published in the New England Journal of Medicine assessed cognitive abilities in nearly 113,000 individuals who had previously contracted COVID-19. The findings revealed significant deficits in memory and executive task performance among the infected individuals. Those with unresolved persistent symptoms, such as shortness of breath or fatigue, experienced a six-point loss in IQ, while those admitted to the intensive care unit had a nine-point loss in IQ. Reinfection with the virus contributed an additional two-point loss in IQ. These declines in IQ highlight the profound impact of COVID-19 on cognitive function.

Considering that the average IQ is about 100, a three-point downward shift in IQ among those with mild and resolved COVID-19 could increase the number of U.S. adults with an IQ less than 70 by 2.8 million, requiring significant societal support. These alarming findings underscore the far-reaching implications of COVID-19 on cognitive health.

Long-Term Effects and Population-Level Impact

Studies also demonstrate that the effects of COVID-19 on brain health are long-lasting and can affect individuals at a population level. An analysis of the U.S. Current Population Survey revealed that after the onset of the pandemic, an additional 1 million working-age Americans reported significant difficulty with memory, concentration, or decision-making, especially among younger adults between the ages of 18 and 44. Similarly, data from the European Union showed that 15% of people reported memory and concentration issues in 2022.

The implications of these findings extend to educational attainment, economic productivity, and the epidemiology of dementia and Alzheimer's disease. The cumulative research affirms that COVID-19 has a substantial impact on brain health, prompting the need for a better understanding of the risks and long-term consequences.

Challenges and the Road Ahead

As researchers continue to unravel the true causes behind cognitive impairments associated with COVID-19, it is evident that addressing this global health concern will require sustained efforts over the coming years. With the widespread impact of COVID-19 on brain health, the need for comprehensive research and intervention is paramount.