Nikhil Prasad Fact checked by:Thailand Medical News Team Aug 02, 2026 43 minutes ago
Scientists Warn Long COVID Could Raise Future Dementia and Parkinson’s Risks
Millions of people have recovered from COVID-19, but growing evidence suggests that the virus may leave behind lasting effects on the brain. A new scientific review has highlighted how long COVID may trigger changes linked to memory loss, depression, anxiety, and even increase the risk of future neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease.
The review was conducted by researchers from the Dr. Jurasz University Hospital in Bydgoszcz, The Mazovian University in Płock, Medical University of Gdansk, Fahrenheit Biobank BBMRI.pl, University Clinical Centre in Gdansk, and the Medical Simulation Centre, Medical University of Gdansk, all in Poland.
Why Long COVID Can Affect the Brain
Although COVID-19 is primarily known as a respiratory illness, researchers explain that SARS-CoV-2 can also have profound effects on the central nervous system. Instead of simply disappearing after the initial infection, the virus may trigger prolonged immune activation, widespread inflammation, blood vessel injury, and damage to the protective blood-brain barrier.
When this barrier becomes weakened, inflammatory molecules and immune cells can enter the brain more easily, causing ongoing injury to nerve cells. The researchers note that this process may continue for months after the infection has resolved, contributing to the symptoms commonly reported by long COVID patients.
Memory Problems and "Brain Fog" Have Real Biological Causes
One of the most common complaints among long COVID patients is "brain fog," a condition marked by forgetfulness, poor concentration, slower thinking, mental fatigue, and difficulty performing everyday tasks.
The review found that inflammation inside the brain can interfere with areas responsible for learning, memory, attention, and decision-making. Elevated levels of inflammatory molecules such as IL-6 and TNF-alpha may disrupt the formation of new brain cells within the hippocampus while reducing communication between neurons.
Brain imaging studies have also shown reduced activity in parts of the frontal and parietal brain regions, thinning of the cerebral cortex, white matter abnormalities, and evidence of damage to blood vessels supplying the brain. This
Medical News report highlights that these biological findings help explain why many patients continue experiencing cognitive problems long after recovering from COVID-19.
Possible Links to Dementia and Parkinson's Disease
Perhaps the most concerning finding is the growing evidence that SARS-CoV-2 infection could accelerate processes already associated with neurodegenerative diseases.
According to the review, persistent inflammation, mitochondrial dysfunction, abnormal protein accumulation, oxidative stress, and activation of immune cells called microglia resemble many of the same biological pathways seen in Alzheimer's disease and Parkinson's disease.
The researchers also discuss evidence showing increased levels of biomarkers linked to nerve cell injury, including neurofilament light chain (NFL), glial fibrillary acidic protein (GFAP), tau proteins, beta-amyloid, and alpha-synuclein. While scientists have not yet proven that COVID-19 dir
ectly causes these diseases, they believe the infection may accelerate existing silent disease or increase susceptibility in vulnerable individuals.
Long COVID Remains a Major Health Concern
The review estimates that long COVID affects between 10% and 43% of infected individuals worldwide, with hospitalized patients facing an even greater risk. Symptoms can develop after severe illness, mild infection, or even asymptomatic cases.
Besides cognitive impairment, patients may experience chronic fatigue, anxiety, depression, sleep disturbances, headaches, mood changes, hallucinations, impaired executive function, and reduced quality of life. Children and adolescents can also develop long COVID, although symptoms and severity vary.
The researchers emphasize that there are currently no definitive biomarkers capable of diagnosing long COVID, making the condition particularly challenging for physicians.
Conclusion
The review concludes that long COVID should no longer be viewed as simply a lingering viral illness but as a condition capable of producing persistent inflammation, vascular injury, and immune abnormalities that may have lasting neurological consequences. Although more long-term studies are needed to determine whether COVID-19 directly causes neurodegenerative diseases, the existing evidence strongly supports continued monitoring of survivors, early cognitive assessment, and the development of therapies aimed at reducing inflammation and protecting the brain before irreversible damage occurs.
The study findings were published in the peer reviewed International Journal of Molecular Sciences.
https://www.mdpi.com/1422-0067/27/15/6897
Read Also:
https://www.thailandmedical.news/articles/coronavirus
https://www.thailandmedical.news/articles/long-covid
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