Older people who have contracted covid-19 have a substantially increased risk of developing Alzheimer’s over the next year, according to a study conducted on more than six million patients 65 years or older.

This is stated in an article published in the specialized magazine Journal of Alzheimer’s Disease, which also indicates that this increased risk is especially pronounced in women older than 85 years.

Infections and inflammation

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The results show that the risk of developing Alzheimer’s in older people it almost doubled (from 0.35% to 0.68%) over a one-year period after infection with covid-19. The researchers, however, point out that it is not clear whether covid-19 triggers the disease or accelerates its emergence.

The factors involved in the development of Alzheimer’s, they say, are not fully understood; but it is known that two important ones are previous infections, especially viral ones, and inflammation.

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Furthermore, it should be noted here that the SARS-CoV-2 infection it has been associated with central nervous system abnormalities including inflammation, which is why the authors decided to test whether the disease was related to an increase in diagnoses, even in the short term.

The emerging consequences of covid-19

To that end, the team analyzed the electronic records of 6.2 million adults aged 65 and older in the United States who received some form of medical treatment between February 2022 and May 2021 and who did not have a previous diagnosis of Alzheimer’s.

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Later, they divided this population into two groups: one who contracted covid-19 during this period and one who had no documented cases of covid-19. Thus, more than 400,000 people were included in the first group, while 5.8 million were included in the second.

What is worrying, they say, is that if this increase in Alzheimer’s diagnoses is sustained over time, the wave of patients with an incurable disease, such as Alzheimer’s today, will be substantial and could a heavy burden on care systems long-term. For this reason, they consider it relevant to continue investigating the long-term consequences of covid-19, especially with regard to neurodegenerative disorders.


Wang, Lindsey et al. Association of COVID-19 with New-Onset Alzheimer’s Disease. Journal of Alzheimer’s Disease (2022). DOI: 10.3233/JAD-220717