The Link between Dementia and COVID-19

By Jane Farrell

People with dementia have a higher risk of getting COVID-19, are more likely to require hospitalization, and are more likely to have severe or fatal cases of this disease compared with people without dementia. This risk is even higher in Black patients with dementia, according to a new study funded in part by the federal National Institute on Aging and published in Alzheimer’s & Dementia.

A person’s age and preexisting health conditions such as asthma, diabetes, heart disease, and obesity are significant risk factors for serious illness from COVID-19. Interestingly, these factors are also linked to dementia. However, scientists and doctors have little information about how COVID-19 affects people who have dementia. The new study, led by researchers at Case Western Reserve University, used information from the electronic health records of about 61.9 million U.S. adults from all 50 states to explore the link between dementia and COVID-19. The data was collected as part of the IBM Watson Health Explorys database. In this dataset, more than 1 million patients had dementia, 15,770 had COVID-19, and 810 had both.

The study found that people with dementia were twice as likely to get COVID-19 compared with people without dementia, even after adjusting for age, sex, living in a nursing home, and having similar preexisting conditions. The researchers suggest that the memory problems associated with dementia might make it difficult for patients to stick to safety measures such as wearing masks, washing hands frequently, and social distancing.

Results showed that 73% of Black patients with dementia and 54% of White patients with dementia were hospitalized within 6 months of their COVID-19 diagnosis, compared with 25% of patients without dementia. Only 20% of Black patients with dementia but not COVID-19 and 12% of White patients with dementia but not COVID-19 were hospitalized within the same time frame. Patients of either race with dementia were almost four times more likely to die from COVID-19 than patients without dementia. The researchers also found that vascular dementia, which is caused by damage to the vessels that supply blood to the brain, led to the highest risk of COVID-19, suggesting that damaged blood vessels might make it easier for disease-causing bacteria and viruses to get from a person’s blood into the brain.

Although their findings need to be replicated using other databases and registries, the researchers note that the study lays the foundation for future research into the interactions between COVID-19 and brain diseases, including whether COVID-19’s effects on the brain increase the risk of or worsen dementia. The study demonstrates the need for innovative and effective measures to protect older adults with dementia from COVID-19 as part of controlling the pandemic and highlights the pressing need to address health disparities.