Causes for concern
“For those people who have COVID, we have seen quite a few sleep issues develop. Those were not reported in the actual study, but in the clinic and subsequent studies published from other places,” Dr. Gozal said.
“People who suffered from COVID, and even people who supposedly did very well and were virtually asymptomatic or maybe had only a headache or fever but did not need to go to the hospital, many of those people reported either excessive sleepiness for a long period of time, and would sleep 2 or 3 hours more per night. Or the opposite was reported: There were those that after recovering reported that they couldn’t sleep – they were sleeping 4 or 5 hours when they normally sleep 7 or 8,” he said.
It’s also unclear from current evidence whether the reported uptick in sleep problems is related to stress or, in patients who have had COVID-19 infections, to physiologic causes.
Dr. Gozal said that insomnia in the time of COVID-19 could be attributed to a number of factors such as less daily exposure to natural light from people sheltering indoors, stress related to financial or health worries, depression, or other psychological factors.
It’s also, possible, however, that COVID-19-related physiological changes could contribute to sleep disorders, he said, pointing to a recent study in the Journal of Experimental Medicine showing that SARS-CoV-2, the virus that causes COVID-19, can bind to neurons and cause metabolic changes in both infected and neighboring cells.
“My guess is that some of it is related more to behavioral impacts – people develop depression, changes in mood, anxiety, and so on, and all of these can translate into difficulties with sleep,” he said.
“It could be that in some instances – not very commonly – the virus will affect areas that control sleep in our brain, and that therefore we may see too much or too little sleep, and how to differentiate between all of these is the area that clearly needs to be explored, particularly in light of the finding that the virus can bind to brain cells and can induce substantial issues in the brain cells.”
Compromised immunity
It has been well documented that in addition to being, as Shakespeare called it, “the balm of hurt minds,” sleep has an important role in supporting the immune system.
“Sleep and immunity go together,” Dr. Ramar said. “When people have adequate sleep, their immune system is boosted. We know that there are good data from hepatitis A and hepatitis B vaccinations, and recently on flu vaccination, that if people get sufficient duration of sleep before and after they receive the shot, their likelihood of building an immune response to that particular vaccination tends to go up.”
It’s reasonable to assume that the same would hold true for COVID-19 vaccinations, but this has yet to be shown, he added.
“We do know from the previous studies that persistent sleep problems can make people more susceptible to infection or impair recovery; not yet, I believe, from the COVID-19 infection perspective,” Dr. Kendzerska said. “In our study, we did find that, among other factors, having a chronic illness was associated with new sleep difficulties during the pandemic. We did not look separately if sleep difficulties were associated with the COVID-19 infection or symptoms, but this is a great question to address with longitudinal data we have.”