One Third of COVID-19 Survivors Show Signs of 'Brain Disease' or 'Psychological Conditions' within Six Months of Infection
Kevin William Grant
Published on
April 07, 2021

Researchers found that 34% of coronavirus survivors received a diagnosis for a neurological or psychological condition within six months of infection, according to the research published in Lancet Psychiatry and other global research studies.

 One-third of people who survived ICU care for COVID-19 showed profound cognitive impairment through poor neuropsychological testing performance compared to those with moderate traumatic brain injury. In daily life, such cognitive effects on memory, attention, and executive function can lead to difficulties managing medications, managing finances, comprehending written materials, and even carrying on conversations with friends and family.

Commonly observed long-term psychological effects of ICU stays include anxiety, depression, and post-traumatic stress disorder (PTSD). Effects due to COVID ICU stays are expected to be similar — a prediction that the studies in Britain have already confirmed in Canada and Finland.

The results help light how health care systems ought to continue assisting COVID-19 survivors. According to research at the University of Oxford, brain diseases and psychiatric disorders are more common after COVID-19 than after flu or other respiratory infections, even when patients are matched for other risk factors. 

While the neurological effects are more severe in hospitalized patients, they are still common in those who were only treated in an outpatient setting, according to the study. 

The research is the largest of its kind and involved the electronic health records of more than 236,000 Covid-19 patients, mainly in the US. 

The findings provide a sweeping view of the long-term burden the virus will have on those it impacted. 

Other, smaller studies have pointed to the same conclusion. Research in February 2021 followed 381 patients treated for COVID-19 at a hospital in Rome, Italy and found that 30% of them experienced post-traumatic stress disorder after recovery.

How COVID Impacts the Brain

COVID can cause damage to the brain directly by encephalitis, which may have devastating or subtle consequences. In one British study of 12 patients with encephalitis, one made a full recovery, 10 made a partial recovery, and one died. This study also found that several patients with COVID suffered strokes. COVID infection is a risk factor for strokes. A group of Canadian doctors found that over 70 were at exceptionally high risk for stroke related to COVID infection. Still, even young individuals are seven times more likely to have a stroke from this coronavirus versus a typical flu virus.

Autopsy data from COVID patients in Finland suggests that another major cause of brain damage is lack of oxygen. Particularly worrisome is that several autopsied patients did not show any brain injury signs during their COVID infection, yet all had brain damage. There was a loss of taste in one patient, and in two, there was “minimal respiratory distress,” but none of these patients were thought to have any brain damage while alive.

A study by doctors from Johns Hopkins University and Harvard Medical School found that large cells called megakaryocytes may be found in the brain capillaries of individuals who died from COVID-19 infection. Megakaryocytes make platelets — part of the body’s clotting system — and these cells should not be there. These neuropathologists had never seen megakaryocytes in the brain before, and this observation had never before been reported in the medical literature. These cells could be related to strokes observed in individuals with COVID-19.

The Subtle Cognitive Effects of COVID-19

COVID can cause brain damage by direct infection (encephalitis), strokes, and lack of oxygen. It is also clear that when patients experience severe illness requiring an ICU stay, brain damage is highly likely to occur, and its effects are typically evident. But what if the COVID illness is not so severe? Can brain damage still happen?

The Long-Term Cognitive Effects of COVID-19 Infection

Why would sustained attention be persistently impaired in individuals who were thought to have fully recovered from COVID?

A Chinese group of doctors and researchers examined several cognitive function aspects in 29 individuals who were thought to have fully recovered from COVID infection. They found persistent impairment in sustained attention — the ability to attend to important information for as long as it is relevant.

The Chinese group thought it might be linked to underlying inflammatory processes. But it is equally likely that patients with COVID suffered silent strokes or lack of oxygen that damaged their brains. As discussed above, strokes due to COVID are common, particularly in those over 70.

We know that silent strokes frequently occur and are a risk factor for large strokes and dementia. Silent strokes typically affect the brain’s white matter — the wiring between brain cells that enables different parts of the brain to communicate with each other. This wiring is essential for attention, and when it is damaged, sustained attention is impaired.


One inevitable conclusion from these studies is that COVID-19 infection frequently leads to brain damage, particularly in those over 70. While sometimes the brain damage is apparent and leads to significant cognitive impairment, the injury is mild, leading to difficulties with sustained attention.

A German and American group of doctors recently concluded that the combination of the direct effects of the virus, systemic inflammation, strokes, and damage to bodily organs could potentially make COVID-19 survivors at high risk of Alzheimer’s disease in the future, although more research is required.

Individuals whose professions involve medical care, legal advice, financial planning, or leadership may need to be carefully evaluated with formal neuropsychological testing, including sustained attention measures, to assure that their cognition has not been compromised. 

Although many people who have recovered from COVID can resume their daily lives without difficulty, even if they have some attention deficits, many people may experience trouble now or later.