Matthew Walker was apologetic. “I don’t want to seem puritanical here,” the British scientist said on one of the newest episodes of his popular sleep podcast, in which he explained the ways in which alcohol does a number on sleep, including by tripping the sympathetic nervous system’s fight-or-flight switch. Sleep becomes more fragile, more “littered with fragmented awakenings,” said Walker, a professor of neuroscience and psychology at the University of California, Berkeley.
When broken down by the liver and kidneys, alcohol’s byproducts also mess with REM sleep, or dream sleep, and without sufficient dream sleep we’re left more anxious, more emotionally unstable and less sharp, mentally.
It may come across as an unpopular message, given surveys suggesting people have been imbibing more than usual to cope with the stressors of COVID-19. But heavier pandemic drinking, and other “maladaptive” and not-so-positive coping strategies likely have contributed to a global pandemic of disturbed sleep, according to some sleep scientists.
“Sleep is pivotal for recovery and physiological adaption to the waking experiences,”British researchers wrote in November in Nature and Science of Sleep, and for many, waking life over the past two years has been marked by unnerving uncertainty, ever-changing health advice, stress — and sleeplessness.
Just half of Canadians think the worst of the pandemic is over,according to a new poll, while some infectious diseases specialists worry the country could experience a European-like wave sometime between now and Feb. 1. How do we keep COVID from keeping us awake at night in 2022?
Vivid dreams and nightmares marked the pandemic’s early waves, as drastic efforts to slow SARS-CoV-2’s spread led to drastic upheavals in individual lives. Dreams became more epic and stranger. Thousands of dreamers who submitted dream diaries to Harvard Medical School academic Deirdre Barrett recounted visions of giant, fanged grasshoppers, swarms of bees and hornets, and masses of bugs and wriggling worms. As the pandemic plodded on, more researchers began cataloguing more disordered sleep. Reported rates of insomnia rose in China, Greece, India and the United Kingdom. Half of more than 5,000 adults surveyed by University of Ottawa researchers reported they were either sleeping more, sleeping less, going to be bed later or waking earlier than they did before-COVID. For many, the boundaries around sleep, when we went to bed, when we woke up, became more flexible. Except nature likes things in a pattern. “And the pattern has changed. And it’s made sleep a little less predicable,” said Colin Espie, a Scottish professor of sleep medicine at the University of Oxford.
Women, those with families, the employed and people in ethnic minority groups were disproportionately affected by disturbed sleep, and while another international study co-authored by University of Laval clinical psychologist Charles Morin found that people living alone were at greater risk of insomnia, so, too, were people living with five or more people in the same household.
We’ve faced uncertainty, a personal and societal threat. And when faced with a novel threat, the human response is that we become more aroused, more hyper-aroused, “and therefore it’s more difficult to sleep, although we need our sleep every bit as much, if not more, in order to cope,” Espie said. “We’ve got to come down from that arousal. “
While all stages of sleep benefit brain and body, rapid eye movement sleep “changes first during chronic stress, and more so than any other measured sleep characteristic,” King’s College London scientists wrote in the Nature and Science of Sleep review. REM sleep is characterized, as Walker explained on his podcast, by the rather “bizarre” side-to-side shuttling of the eyeballs beneath closed eyelids. It’s during REM sleep that people experience long narratives, “hallucinogenic” and emotionally filled dreams, he said. It’s also when new brain neuro-connections are made, a sleep stage believed vital for memory storage.
What even makes us sleepy? A chemical in the brain called adenosine that acts like a hypnotic slowly builds up in the blood over the course of the day. Once the concentration is high enough, after about 12 to 15 hours of wakefulness, it signals to the brain: “Bed time.” The person experiences a drive, a pressure for sleep. Over the course of the night, adenosine is gradually purged from the brain.
Caffeine can keep people awake by inactivating receptors for adenosine. Napping late in the afternoon also impacts adenosine levels by releasing some of the sleep pressure, a bit like letting a bit of air out of a balloon, making it harder to fall asleep and stay asleep later that night. Walker recommends avoiding naps after 2 p.m. and limiting them to less than 20 minutes.
As for booze, whether a “wee drink” or several, “all we are doing is losing consciousness more quickly, not going into naturalistic sleep,” he cautioned.
Insufficient sleeps affects the secretion of cortisol, a stress hormone that also controls blood sugar levels and appetite. Several consecutive nights of four hours’ sleep can also increase ghrelin, the hunger hormone, while lowering leptin, the hormone that signals to the brain, “I’m full.” People crave carb-dense and sugary processed foods. Insulin rises, “and all those hormones that cause you to store sugar as fat are sky high,” said Toronto physician Dr. Elaine Chin, and the health toll goes on and on. Poor sleep affects mood, the immune system’s ability to fight viruses and bacteria, and may increase the risk of prostate and breast cancer, heart disease and Alzheimer’s.
Sleep is crucial for optimal brain functioning, Espie said. Sleep gives the brain, the body’s command centre, “the opportunity to get on with things when we’re out of the way,” like cell regeneration, immune signalling and functioning, learning and memory and emotion regulation. “The brain needs that time to do all these important tasks, a time when we’re not using up lots of energy when we’re preoccupied with everything else.”
But COVID has also helped expose a chronic sleep debt. “Paradoxically, 25–28 per cent of individuals with pre-existing insomnia disorder reported clinically meaningful improvements in sleep quality during the pandemic, suggesting that changes in sleep in response to the stressor of the pandemic are not uniform across individuals,” the King’s College team reported, perhaps because lockdowns reduced the stress of work and social commitments.
Still, “as we have seen with other pandemics, insomnia and associated daytime dysfunction persist long after the threat of infection has passed,” and post-COVID-19 clinics should ideally include sleep doctors, they said.
A rare silver lining is that it nudged people to step back, “and reflect on how they live and sleep, and particularly how they work,” they wrote.
“Workplaces may need to think about adopting more flexibility in terms of working from home, or flexible work hours in industries that permit this, so that employees can better align their work and sleep with their own natural body clocks — which will make them happier and more productive in the long run.”
Long-held sleep advice remains steady: keep the bedroom cool and dark, be mindful of caffeine and alcohol, resist the urge to sleep in the next morning after a bad night’s sleep, get out of bed if you wake at night and can’t fall back asleep after 20 to 30 minutes, move to another room to read a book or listen to a podcast. A warm bath or shower 90 minutes before bed can stimulate melatonin, the hormone that helps regulate sleep. Avoid lights from devices and “doom scrolling.” Cognitive behavioural therapy can help with chronic, unrelenting insomnia. And while ruminating isn’t healthy, neither is orthosomnia, the “perfectionist quest for the ideal sleep.”
Tips like these, colloquially known as “sleep hygiene” are important, even though they can “feel a little superficial” at times, Espie writes in his “5 principles of good sleep health.”
“After all, sleep is fundamental to every living organism. Cats and dogs, birds and butterflies don’t sleep well because they leave their smartphones in the living room, or because they cut down on their Americano intake.”
“What concerns me is that we are still primarily medicating people for insomnia, anxiety, and depression,” he said. “The pandemic itself is a coronavirus threat and requires medicine (vaccine). However, the mental distress is not a direct effect of the virus.” Instead, it results from that sense of threat and uncertainty, which Espie said is best addressed using psychological interventions such as CBT.
Espie’s advice involves valuing sleep as much as clean water, good food “and the air that you breathe,” prioritizing sleep not just with “warm thoughts and good intentions” but action, figuring out how much people personally need to sleep by trial and error (part of this is about personalizing your “chronotype,” meaning, are you more a night owl or morning lark?) and resisting the temptation to grab at anything, trying this and that. “It absolutely doesn’t work to be frenetic and to overthink the whole thing,” Espie said.
Wind down from mid-evening on, he recommended, and know that if you wake at night, you aren’t alone.