- Rachel Schreyer
- Health affairs correspondent
Researchers have found that people who have had Covid-19 in the past six months were more likely to have depression, dementia, psychosis and stroke.
The researchers found that a third of those who had previously had a Covid infection either became suffering from psychological or neurological conditions, or they had relapses of cases that were already existing.
The injured, who were transferred to hospitals or intensive care departments, were more at risk.
It is likely that this is caused by the consequences of stress, as well as the direct effect of the virus on the brain.
Scientists in Britain examined the electronic medical records of more than half a million patients in the United States, and looked at their likelihood of having one of the 14 common neurological or psychiatric conditions, which include:
- Cerebral hemorrhage
- brain attack
- Parkinson’s Disease
- Guillain-Barre syndrome
- Mood disorders
- Anxiety-induced disturbance
The researchers explained that anxiety and mood disorders were the most common diagnoses among people with Covid-19, and that this was most likely due to the stress of experiencing severe illness or taking them to hospital.
It is more likely that conditions such as stroke and dementia were due to the biological effects of the virus, or the body’s reaction to infection in general.
Covid-19 was not associated with an increased risk of Parkinson syndrome or Guillain-Barre syndrome (which may be caused by influenza).
Cause and effect
The study was observational, so the researchers were unable to determine whether Covid had caused any of the previous diagnoses, and whether it was possible that some people had a stroke or depression in the six months that would have occurred regardless of infection with the virus.
By comparing a group of people who have contracted Covid-19 with two other groups, in one of them individuals with influenza, and in the second with infections in the respiratory system, researchers at Oxford University have concluded that Covid is linked to later brain conditions, more than other respiratory diseases.
The researchers made sure that the participants matched their age, gender, ethnicity, and health conditions, so that a comparison could be made.
It was found that people with Covid are 16 percent more likely to have a mental or neurological disorder, compared to those with other respiratory infections, and 44 percent more likely to have recovered from influenza.
In addition, the more serious a patient has a Covid, the more likely he or she will later develop a mental health disorder or a brain disorder.
Mood, anxiety, and psychotic disorders affected 24 percent of the total patients. But this percentage rose to 25 percent for patients who were hospitalized, to 28 percent for people who were in intensive care, and to 36 percent for people who experienced delirium during illness.
Strokes affected 2 percent of all Covid patients, and the percentage increased to 7 percent among those transferred to intensive care units, and 9 percent among those with delirium.
Cases of dementia were diagnosed in 0.7 percent of all Covid patients, but the rate was 5 percent among those who suffered from delirium as a symptom.
Sarah Imaricio, head of research at the Alzheimer’s Research Center in Britain, said: “Previous studies indicated that people with dementia are at greater risk of contracting severe Covid-19 virus. This new study verifies whether this relationship exists in the opposite direction.”
She adds: “The study does not focus on the reason for this relationship, and it is important for researchers to reach what lies behind these results.”
Masoud Hussein, a professor of neuroscience at Oxford University, explained that there is evidence that the virus enters the brain and causes direct damage.
It can have other indirect effects, such as affecting blood clotting that can lead to strokes. The general inflammation that occurs in the body when it responds to infection can affect the brain.
For just over a third of people diagnosed with one or more of these conditions, this was their first diagnosis.
The researchers say that even in the case of a recurring problem that previously existed, this does not mean that it is not excluded that Covid is the cause of the new episode of the disease.
“The study confirms our suspicions that the diagnosis of the Coronavirus is not only related to respiratory symptoms, but also related to psychological and neurological problems,” said Tale Wakes, from the Institute of Psychiatry, Psychology and Neuroscience at Kings College London.
She adds: “After more than six months of diagnosis, it became clear that” after-effects “could appear much later than expected, which is not surprising for those who suffer from long-term Covid disease.
And she said: “Although, as expected, the results are more serious among those who were transferred to the hospital, the study indicates that dangerous effects also appear in those who were not transferred to the hospital.”