For almost all of us, the current COVID-19 pandemic represents the first time we have been confronted with a personal and proximate threat to our lives. Accordingly, we have supported the current strategy of personal shut-downs, social distancing and health care ramp-ups to deal with the cases of acute severe infections. But at some point, likely within a year, this will end. The virus will be contained or even killed by medicines, and a preventative vaccine will likely be developed. For most people, including politicians, this will be seen as the end of the episode, but in truth it will not be. The sequelae of COVID-19 will reverberate through a significant percentage of the population, maybe hundreds of thousands of people, for years if not for the rest of their lives. These sequelae will manifest in brain disorders – both neurologic and psychiatric, and so we should be preparing for them now.
Many viral epidemics lead to a significant number of those infected developing neurologic conditions. One reason we try to immunise all children against measles is to eliminate the rare but devastating neurologic consequence of chronic encephalitis. Flu outbreaks often lead to brain damage. The most vivid example is that of the chronic sleeping-sickness [encephalitis lathargica] described by Oliver Sacks in his book ‘Awakenings’. These illnesses followed the 1918 flu pandemic and left hundreds of people in a semi-comatose locked-in state. In the 1950s it was discovered that the virus had damaged the neurons in the brain that make the neurotransmitter dopamine and by replenishing this with by treatment with L-dopa the patients were released from their semi-coma.
When I started working as a psychiatrist in the 1970s I saw patients with severe depression whose illness had been precipitated by the 1957 flu epidemic that infected over 9 million people in the UK. I presumed that this variant of the virus had damaged neurons that produced mood-maintaining neurotransmitters such as noradrenaline and serotonin though at the time we didn’t have the ability to explore this in their brains. Now modern neuroimaging techniques especially positron emission tomography give us the tools to explore both changes in neurotransmitters in living humans and the neuroinflammation that might damage them.
COVID-19 is clearly neurotoxic. It often presents with a peripheral neurologic syndrome especially loss of taste and smell, and sometimes of itch. Headaches are very common and likely represent a form of encephalitis. Exacerbation of ongoing neurologic conditions such epilepsy is also reported. We know other corona viruses can get into the brain and even be passed from neuron to neuron and it may be some of the fatalities of COVID-19 are due to damage to the crucial breathing and cardiac centres of the brain stem, where these viruses seem to congregate. Only time will tell if these immediate effects leave an enduring trace, so it is important to set up diagnostic processes to capture this possibility.
The majority of those infected probably won’t experience enduring neurologic problems but very many more will end up with psychiatric problems. The general population has experienced raised levels of anxiety from the fear of infection, coupled with loss of income and the prospects of an economic downturn. This is especially problematic for people with ongoing anxiety disorders such as OCD with a fear of contamination by germs. Their suffering has been exacerbated by the (partial) closure of ongoing psychiatric treatment systems as part of the COVID-19 response and the self-isolation requirement.
Health care professionals are especially at risk of COVID-19 infection, a fear exacerbated by the under-provision of protective equipment and increased levels of mental strain caused by the increased workload. Many will have seen things out with their usual clinical experience that they felt helpless to deal with and this can lead to a form of post-traumatic stress disorder [PTSD].
Those people whose infection leads to hospitalisation are at a much-increased risk of PTSD, as are their families who fear the worst and are excluded from close supportive interactions. Up to a third of patients admitted to ITU end up with ongoing psychiatric problems and this proportion is likely to higher with a virus that significantly affects the brain. From this analysis, I predict that PTSD and depression will be the major long-term medical consequences of COVID-19. We should be preparing for them now to minimise their frequency and impact otherwise the enduring burden of psychiatric illness will be huge, very costly to society, and maybe the most problematic legacy after the economic crisis.
Whilst there are efforts being put in place to assist with health care professionals stress now this won’t solve the long term problems. We need a systematic plan to evaluate the neurologic and psychological outcomes of COVID-19 infection and put in place proven interventions for conditions such as PTSD and depression as well as facilitating new treatments such as medical cannabis, MDMA and psilocybin [or other psychedelics such as ayahuasca]. Already movements in this direction are in place – on the 21st May the OCD charity Orchard is launching a crowd-funding campaign to raise money for a psilocybin trial in OCD to be run by the UK’s leading OCD expert Prof Naomi Fineberg with our Imperial College team.
The current medical response to the virus shows that UK health care and research leaders can work together quickly and effectively in response to the immediate threat of infection. We need a similar task-force to be set up now to instigate a wide-ranging treatment programme that optimises current and facilitates novel currently illegal drug treatments. Only with this approach can we minimise the long-term consequences of this COVID-19 pandemic on brain health.
David Nutt FMedSci