The first widespread reports that COVID-19 might be affecting our nervous system were quite innocuous. We first reported back in March that doctors had noted many patients who were otherwise asymptomatic had lost their sense of smell and taste before testing positive for the SARS-CoV-2. Whilst an obvious inconvenience (it’s particularly cruel to be denied the sensory relief that a tub of ice cream has brought to many during this crisis), these symptoms seemed quite mild as compared to the crippling effects on the respiratory system that were then the hallmark of acute COVID-19.
But over the weeks and months since, reports of far more severe neurological side effects of COVID-19 have emerged. The publication, in the journal Brain, of a detailed series of case reports from clinicians at University College London Queen Square Institute of Neurology have catapulted COVID-19’s impact on the brain into the headlines. Another recent review, published in The Lancet Psychiatry, looked at the literature around the links between coronaviruses, including SARS, MERS and SARS-CoV-2, and psychiatric side effects. Analyzing 65 published studies and 7 preprints, it’s the first paper of its kind to review this connection. To explore the psychiatric side effects of coronavirus infection further, Technology Networks spoke to psychiatrist Dr Jonathan Rogers, Wellcome trust clinical training fellow at University College London and lead author of the paper.
What psychiatric side effects do coronavirus patients show?
Rogers’ review highlighted a number of common psychiatric presentations among patients infected with coronaviruses:
Acute clinical signs
Delirium: Rogers clarifies this clinical sign, which is a term commonly used, but less commonly understood, “Delirium is when people become rapidly confused when they are medically unwell. People are disoriented, have poor attention and may even hallucinate, become paranoid and not know where they are,” says Rogers. Whilst delirium often lessens after people recover from their illness, Rogers says that it’s important to consider that people with delirium have worse outcomes. “People with delirium are more likely to die in hospital, to die in the months after leaving hospital and there is some evidence it can have a long-term effect on your cognition and memory.”
Mood disorders: Roughly 15% of patients analyzed in the review, says Rogers, had depression and anxiety diagnosed at follow-up. What was especially stark, he notes, was the rate of post-traumatic stress disorder (PTSD), which was high, at around 30% of patients at follow-up. It’s important to note that in the studies reviewed, these chronic symptoms were only measurable in SARS and MERS patients. Long-term psychiatric follow-up data for COVID-19 patients do not yet exist.
Fatigue: Patients commonly reported feeling tired out and exhausted, and Rogers says that patients additionally said that the care they received for this was much poorer than that given for the actual symptoms of coronavirus infection.
A psychiatric signature of coronavirus infection?
These findings, says Rogers, come with a number of important caveats. The rates of delirium seen in the review were at about 20-25%. “That’s high,” says Rogers, “but not super-high for patients who are admitted to hospital. If you are young and fit and have appendicitis, you probably won’t get delirium, but it’s more common in the elderly and among people who have a fever.” This is, of course, the exact group who are being admitted to hospital with signs of COVID-19.
Furthermore, the rates of depression and anxiety seen in this study might sound high, but actually are grimly similar to those seen in the general population – 40 million US adults are affected by an anxiety disorder, according to the ADAA. The rate of PTSD, affecting nearly one-third of coronavirus survivors, is certainly higher than that seen in the general population, but, the authors of the review note, not dissimilar to that seen in other studies of people who have survived a critical illness in hospital.
Fatigue symptoms caused by coronavirus infection, persisting long after other clinical signs have subsided, have been a common feature of anecdotal reports of people recovering from COVID-19. Such analyses don’t yet exist in the published literature, says Rogers, but the data from SARS and MERS patients also points to long-term effects on energy levels. For ICU patients, this is a given, as every day means further muscle mass atrophy, says Rogers. The effect this has on the body, he says, is “absolutely massive.”
Discharged patients, says Rogers, can get into cycles where they think they have recovered enough to exert themselves normally without realizing the full impact of what their body has been through. “They have a good day, so they do loads of exercise, and the following day they are absolutely shattered,” he says. But is the fatigue inflicted by coronaviruses unique? “We don’t really know at the moment,” says Rogers, “Inflammation is probably important, and certainly inflammation seems to be really important in terms of who becomes unwell from a respiratory point of view.”
The influence of mass panic
COVID-19’s unique and unexpected effects on patients’ bodies have been trickling into news reports and case studies regularly over the last few months. Patients with horrific lung scarring and unusually thick blood are good examples. But does the disease have a unique psychiatric signature? Rogers says there is a lot of debate on the topic that is still ongoing. “What we can say is that a lot of the psychiatric morbidity of COVID-19 looks like the psychiatric morbidity of people admitted to intensive care,” says Rogers.
Nevertheless, the context of the pandemic means that psychiatrists like Rogers have reasons to believe some of the impact may be unique to COVID-19. “The mass panic surrounding it and the fact that being admitted to hospital is very different,” are likely to have been influencing factors, says Rogers. A lack of family visits and interactions with doctors through thick protective screens contributes make for an often-terrifying clinical experience. “I’ve seen patients who are objectively getting better,” says Rogers, “but believe they are going to die because of what they have heard about this dreadful virus.” Other unique factors are related to some of the neurological effects of the disease, such as increased risk of stroke.
One final consideration, says Rogers, is the need for better studies of the psychiatric effects of coronaviruses. Of the 65 published studies reviewed, the team only identified three that were high quality. A lack of controls and limited assessment of psychiatric symptoms pre-infection were important limitations. He also highlights that follow-up studies that look at how people with immunity to the virus compare with people who were never infected will be important. Far from being a respiratory condition, it’s clear that researchers are just beginning to scratch the surface of what COVID-19 does to the body.