New study reveals potential brain mechanisms behind COVID-19 delirium

Researchers from Kings College London are the first group to use blood samples from COVID-19 patients to investigate why some people with the disease have developed delirium. 

They found that when brain cells are exposed to blood taken from COVID-19 patients with delirium, there is an increase in cell death and a decrease in the generation of new brain cells.  

Delirium is a state of confusion which can indicate an infection has affected the brain and is associated with prolonged hospitalisation and even death.  

The study, published in Molecular Psychiatry, analysed 36 patients who had been  admitted to Guy’s and St Thomas’ NHS Foundation Trust in London during the first wave of the pandemic. 

Half of the patients were experiencing delirium symptoms whilst the other half had no symptoms at the time of hospital admission. 

Researchers used a human cell model consisting of cells from a part of the brain fundamental in many cognitive, memory and learning skills. Professionals treated cells from this area with serum samples and observed the impacts on cell generation and death. 

Results showed that treatment with serum taken from COVID-19 patients with delirium increased cell death and decreased the generation of new brain cells.  

Funded by Rosetrees Trust and the National Institute for Health and Care Research (NIHR), the research indicates inflammatory proteins, produced by the immune system during infection, could help contribute to future treatments. 

Dr Alessandra Borsini, National Institute for Health and Care Research Maudsley BRC Senior Research Fellow, said: ‘Research is indicating that there is a neurological element to serve COVID-19 infection. 

‘Our research is the first to use blood samples from COVID-19 patients experiencing delirium to investigate how the infection impacts a process called neurogenesis, which is essential to maintain intact brain functions, including memory and thought process. 

‘We have found that there is a reduction in the generation of new brain cells and an increase in cell death, and these are likely mechanisms behind delirium in COVID-19 patients.’ 

Carmine Pariante, Professor of Biological Psychiatry at the Institute of Psychiatry Psychology and Neuroscience said, ‘The role of inflammation and our immune response in COVID-19 infection is well-known, but research like ours is now revealing how it affects our brain, our thinking and our mental health. 

‘These neurological symptoms are very concerning for patients and their families, and the hope is that our research can help identify which treatments would be most appropriate to lessen or prevent these symptoms.’ 

Photo by Steven Cornfield

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