The COVID-19 pandemic has had far-reaching consequences on various aspects of society, including physical and mental health. Recent data from the PROTECT study in England suggests that individuals aged 50 and older experienced a rapid deterioration in brain health during the pandemic. The study, led by Anne Corbett, PhD, from the University of Exeter, examined the effects of the pandemic on cognitive function and found concerning declines in executive function and working memory among participants. These findings raise important questions about the potential long-term impact on brain health and the risk of cognitive decline and dementia in the aging population.
Worsening Cognitive Function
According to the PROTECT study, both executive function and working memory worsened across the entire cohort of 3,100 people during the first year of the pandemic. The effect sizes for executive function and working memory were 0.15 and 0.51, respectively. These declines were further observed in individuals with mild cognitive impairment and those who had contracted COVID-19, albeit with slightly different effect sizes. In the second year of the pandemic, the deterioration in working memory persisted among the entire cohort, with an effect size of 0.47.
The decline in cognitive function was found to be associated with several known risk factors for dementia. Increased alcohol use and reduced exercise were among the lifestyle factors linked to cognitive decline. The restrictive measures, such as lockdowns and social isolation, imposed during the pandemic likely contributed to these changes. The study suggests that the impact of these restrictions on brain health persisted even after the lockdowns ended, emphasizing the need for policymakers to consider the broader health implications of such measures in future pandemic responses.
The consequences of the COVID-19 pandemic and the associated restrictions extend beyond respiratory symptoms. Dorina Cadar, PhD, from Brighton and Sussex Medical School, highlights the overwhelming evidence of pandemic-related effects on mental health, including isolation, loneliness, post-traumatic stress, depression, fear, anger, and confusion. The physiological effects of SARS-CoV-2 on the central and peripheral nervous systems are also becoming increasingly evident.
Corbett and colleagues analyzed neuropsychological test data from over 3,100 participants aged 50 and older in the PROTECT study. The evaluations were conducted at three time points: before the pandemic, during its first year, and during its second year. The tests assessed executive function and working memory, two critical cognitive domains. The researchers also collected data on lifestyle factors and conducted annual depression assessments.
The study results showed significant associations between cognitive decline and reduced exercise, increased alcohol use, depression, and loneliness. These relationships were observed both in individuals with a history of COVID-19 and those with mild cognitive impairment. The sustained decline in cognition underscores the need for public health interventions to mitigate the risk of dementia, particularly in individuals with mild cognitive impairment who face a higher risk of conversion to dementia within five years.
It is essential to acknowledge the limitations of the study. The PROTECT cohort is not representative of the general population, as it is self-selected and skewed towards individuals with higher education levels. The relatively small number of individuals with mild cognitive impairment also limits the generalizability of the findings. Additionally, the study’s observational nature prohibits establishing causality, and other confounding factors may have influenced the results.
The PROTECT study highlights the substantial impact of the COVID-19 pandemic on brain health, particularly among individuals aged 50 and older. The decline in cognitive function, particularly in executive function and working memory, raises concerns about the potential long-term consequences and the increased risk of dementia. Future public health interventions should focus on mitigating cognitive decline and supporting cognitive health, both in individuals with a history of COVID-19 and those with pre-existing cognitive impairment. The findings also emphasize the need for policymakers to consider the broader health implications of pandemic-related restrictions when planning for future responses. By addressing the consequences on brain health, we can ensure the well-being of our aging population in the face of future challenges.