Thread by @ZdenekVrozina

A new 5-year study from Brazil shows that surviving COVID-19 can significantly alter the natural course of Alzheimer’s disease (AD).🧵

Patients who had COVID-19 were nearly five times more likely to experience rapid cognitive decline (measured by MMSE).
Their memory, orientation, and mental abilities worsened faster than expected for typical AD progression.

Katz Index scores dropped, showing patients became less able to perform daily activities - washing, dressing, eating.
This decline appeared even after mild COVID-19, not only in those who were hospitalized.

At 5-year follow up, patients who had been hospitalized for COVID-19 showed lower survival than those who never caught the virus.
SARS-CoV-2 can have lasting effects on both health and survival in AD patients.

What it means.
The impact of COVID-19 on AD was detectable years later - not just a temporary post-infection effect.
Cognitive and functional decline occurred across all severities of COVID-19, not only severe cases

The authors suggest that SARS-CoV-2 may accelerate Alzheimer’s pathology, although the precise biological mechanism remains to be determined.

This is the 5-year follow up (!) showing that COVID-19 can accelerate Alzheimer’s progression and worsen long-term outcomes.

People with Alzheimer’s who had COVID-19 may need closer monitoring for faster cognitive and functional decline.
The authors call for larger, multicenter studies to confirm causality and identify risk factors.

Ursi at al., Alzheimer Disease & Associated Disorders 2025. Alzheimer Disease Patients Who Survived COVID-19 Have Rapid Disease Progression and a Higher Risk of Death at 5-year Follow-up. journals.lww.com/alzheimerjourn…

Previous work already hinted at this:
Wang et al., 2022 (J. Alzheimer’s Disease) - COVID-19 increased the risk of a new Alzheimer’s diagnosis by 50-80 % in older adults.
BMC Geriatrics, 2024 - meta analysis confirmed higher risk of new-onset dementia after COVID-19. Etc.
Ursi et al., 2025 now adds the missing piece - in those already living with AD, SARS-CoV-2 can speed up the disease itself.

These findings highlight a growing blind spot in pandemic policy.
Faster cognitive decline after COVID-19 means more patients entering advanced Alzheimer’s stages sooner -increasing the burden on families, caregivers, and already overstretched healthcare systems.

Yet, there are no systematic post-COVID monitoring or prevention programs for neurodegenerative outcomes.
Ignoring this link between infection and brain aging is a public health failure in slow motion. @szupraha @ZdravkoOnline @adamvojtech86

@szupraha @ZdravkoOnline @adamvojtech86 To clarify - the two earlier studies (Wang et al., 2022; BMC Geriatrics 2024) looked at new-onset dementia or Alzheimer’s disease after COVID-19 in people who had no prior diagnosis.
They showed that infection can trigger or accelerate the appearance of Alzheimer-like pathology.

@szupraha @ZdravkoOnline @adamvojtech86 By contrast, this Ursi 2025 focused on patients who already had Alzheimer’s disease before infection.
It shows that COVID-19 can accelerate the existing neurodegenerative process itself - leading to faster cognitive decline, loss of independence, and higher mortality.

@szupraha @ZdravkoOnline @adamvojtech86 Together, these findings outline a double impact
the possibility of more new Alzheimer’s cases emerging after COVID-19
faster progression in those already affected
Both trends increase the long-term burden on healthcare systems and caregivers.