Numerous recent research pieces suggest reasons for concern regarding the long term effect of covid on mental health. An article by Andrew E. Budson, MD in the Harvard Medical School 1 reports that research is now suggesting that there may be long-term neurologic consequences for those who survive COVID infections. Budson’s article points to increasing evidence that there may be mild brain damage that occurs in many survivors, causing persistent yet subtle cognitive, behavioural, and psychological problems.
According to the article a number of studies have suggested that COVID can cause damage to the brain directly by encephalitis. It mentions a British study found that a number of patients with COVID suffered strokes leading to the conclusion that COVID infection is a risk factor for strokes.
Separately a group of Canadian doctors found that individuals over 70 years of age were at particularly high risk for stroke related to COVID infection, but even young individuals were seven times more likely to have a stroke from this coronavirus compared to a typical flu virus. Autopsy data from COVID patients in Finland suggested that another major cause of brain damage is lack of oxygen. Of particular concern is that several of the patients studied did not show any signs of brain injury during the course of their COVID infection — yet all had brain damage. In one patient there was loss of taste, and in two there was “minimal respiratory distress,” but none of these patients were thought to have any brain damage while alive.
A new 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. In fact, these neuropathologists had never seen megakaryocytes in the brain before, and this observation had never before been reported in the medical literature. It is thought these cells could be related to strokes observed in individuals with COVID-19.
Major cognitive effects of COVID have been observed in COVID survivors who have undergone ICU treatment as a consequence of acute respiratory failure or shock from any cause. In such cases one-third of people show such a profound degree of cognitive impairment that performance on neuropsychological testing is comparable to those with moderate traumatic brain injury. In daily life, such cognitive effects on memory, attention, and executive function can lead to difficulties such as 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).
However, some of the cognitive effects of COVID appear to be far more subtle. The article points out that, whilst it may be more obvious that COVID can cause brain damage by direct infection, for example as a result of encephalitis, strokes, by lack of oxygen, or when patients experience severe illness requiring an ICU stay, there is also evidence to suggest that even in less severe cases there can be persistent impairment in sustained attention. It points to research by a Chinese group of doctors and researchers that found long-term cognitive impairment in such cases.
One possible explanation for this was that it might be linked to underlying inflammatory processes. But the research found that it is equally likely that patients with COVID suffered ‘silent strokes’ or lack of oxygen that damaged their brains. 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 is essential for attention, and when it is damaged, sustained attention is impaired.
There is one inevitable conclusion from these studies: COVID infection frequently leads to brain damage — particularly in those over 70. While sometimes the brain damage is obvious and leads to major cognitive impairment, more frequently the damage is mild, leading to difficulties with sustained attention.
Although many people who have recovered from COVID will resume their daily lives without difficulty, there are a number of people who may experience problems now or later. One recently published paper from a group of German and American doctors concluded that the combination of direct effects of the virus, systemic inflammation, strokes, and damage to bodily organs (like lungs and liver) could even make COVID survivors at high risk for Alzheimer’s disease in the future.
It may take some time for the true breadth and depth of the long term neurological impact of Covid to be fully appreciated but the evidence suggests reason for significant concern on the mental well-being of our society.
