In addition to over 6.5 million deaths, 200,000 small business closures, and the ongoing trauma of kids experiencing increased instances of depression, anxiety and mental health issues, COVID-19 caused nightmares.
A new study published in the Nature and Science of Sleep medical journal found those diagnosed with COVID-19 reported increased instances of nightmares.
The study surveyed thousands of individuals across 14 countries and compared pre- and post-pandemic reports on dream recall and nightmare frequency.
It found the more people were affected by COVID-19, the greater impact it had upon their dream activity and overall quality of life.
In addition to individuals diagnosed with COVID-19, the study also found lockdowns, isolation, and other mitigation measures increased overall symptoms of anxiety, depression and PTSD, all of which contributed to an overwhelming increase in nightmares and dream activity reported by respondents.
“Dream characteristics and above all, nightmares, are possible correlates of COVID-19,” the report found, adding “Our study is unable to determine if the effects on dreaming activity are explained by the infection per se, or by its impact on the general psychological and mental adaptation to the infection.”
The frequency of nightmares increased by 50% in the group diagnosed with COVID-19, and 35% in the control group.
Researchers also found the severity of the disease played a part in how terrifying the nightmares became. Participants reporting a moderate or serious form of the disease were more susceptible to nightmares than those with minor infections.
An additional study published in the Journal of Sleep Research found increased dream recall during the pandemic centered around four main topics: inefficiency (such as arriving late, or trying things repeatedly without results); human threat (being chased or attacked); death; and pandemic imagery (being separated from loved ones, being sick, forgetting a mask, or other isolation settings).
Stress influenced the content of respondents nightmares as well, with different sources of stress being linked to specific nightmare themes.
“Dream content during the lockdown broadly reflected existential concerns and was associated with increased symptoms of mental health indices,” the report states. “The unique lived experience of life under a pandemic lockdown produced changes not only in general mental health and sleep patterns, but also in oneiric life, reflecting in a general sense, the ongoing existential challenges.”
One major cause outside the disease itself were disruptions to circadian rhythm that occurred when spending more time at home. The body’s internal clock regulating the sleep-wake cycle was impacted from the absence of typical social and daylight cues that people rely on. Another factor was the increased time spent in front of blue-light emitting screens.
“Our study showed those who were more stressed about COVID-19 and experiencing worse sleep were more likely to be experiencing nightmares with themes of confinement, sickness, death, anxiety, war, apocalypse and totalitarianism,” study author Kathryn Kennedy told PsyPost. “There’s good evidence showing that sleep is a time for us to make sense of our daytime experiences to help us regulate our emotions. Working from home, dealing with job or financial losses, and a public health crisis can all manifest in our dream themes at night.”
There was also a significant increase in overall sleep times throughout the world, and the influx of dreams might correlate with increased nightmares.
One study from China analyzing stay at home orders indicated people reported an average increase of 46 minutes in bed, with 34 minutes of additional sleep time. Another 54% of people in Finland also reported they slept more during lockdowns. In the U.S., overall sleep time increased almost 20% nationwide, and states with longer commute times like Maryland and New Jersey showed the largest increases.
But maybe it’s not just stress and anxiety. Studies regarding the impact of COVID-19 on the brain may have contributed to world-wide changes taking place in our subconscious.
Brain autopsy data from Stanford collected from those who died of COVID-19 confirmed many suspicions, that the disease was linked to damaged blood vessels and inflammatory cells located in the brain.
This could explain the diseases impact on our senses and commonly reported symptoms including the loss of taste and smell associated with the Delta variant. It might also explain the lingering “brain fog” reported by those experiencing long-term COVID infections.
The connection between dreams and senses have been analyzed before.
One study indicated that people experiencing different types of headaches and migraines reported increased frequency of dreams involving taste and smell. The connection suggested that some cerebral structures, such as amygdala and hypothalamus, are involved in migraine mechanisms as well as the biology of sleep and dreaming.
Another study, published in the Journal of the American Medical Association, found that even mild COVID-19 infections could effect the brain.
Comparing the brain scans of over 800 individuals before and after a COVID-19 infection, post infection brains showed an average 2% gray matter loss along with tissue abnormalities, mainly in the areas of the brain associated with smell, like the olfactory cortex.
The scans also found a significant decrease in whole-brain volume and an increase in cerebrospinal fluid volume. Loss of cerebrospinal fluid resulted in atrophy of crus II, an area of the cerebellum associated with cognition. This could cause an increased inability to complete basic tasks and functions.
The scans were compared to those who developed non-COVID-19 pneumonia, showing minimal overlap.
The cause is often cited as neuroinflammation, or immune reactions, as well as a direct viral infection of brain cells. The changes have led some researchers to present a link between COVID-19 and other neurological complications, such as strokes and brain hemorrhages.
Exactly how the virus finds its way into the brain via nerve cells is still under investigation, as the surface of these cells appear to lack the molecular anchor points - the ones found in lung cells, for instance - that are needed for a forced invasion into the interior of the cell.
One possible answer is the NRP1 receptor, present on nerve cells both in the brain and in the olfactory tract, which couples with an enzyme on the surface of the cells called furin, permitting viral passage.
Another possible portal is the peripheral nervous system, which conveys sensory and motor impulses from muscles, organs, and skin to the brain and spinal cord. When tested on infected mice, these peripheral nerve groupings stretched out to various areas of the brain, which might explain the nerve pain and tingling symptoms experienced by some COVID patients.
But even if we know the virus has the possibility of entering the brain, where does it go from there, and what are the implications?
Several scientists are studying viral dispersal, one involving rhesus monkeys and a subgroup with diabetes. Researchers found traces of the virus in the rhesus monkeys spread across several regions of the cerebral cortex, especially in the diabetic animals, finding additional dead neurons in the olfactory cortex. This might explain the connection between weight and the severity of a COVID-19 infection, as well as the persistence of symptoms.
“The direct entry (of the virus) to the olfactory system, productive infections of neurons, and transport to multiple brain regions are likely the cause of neurological complications in COVID-19,” said John Morrison, professor of neurology at the UC Davis School and director of the study.
One area where the virus was present in the diabetic monkeys was the entorhinal cortex, what Morrison calls the “single most vulnerable brain region to Alzheimer’s disease.”
“So once the virus is there,” he said, “It can play into mild cognitive impairment and dementia.”
Regardless of the cause, COVID is not the only collective trauma event that has reportedly increased nightmares. A similar effect was reported after the 9/11 terrorist attacks and the 1989 San Francisco earthquake.
“A change in dreams due to a crisis is very common,” said Deirde Barret, a dream researcher and assistant professor of psychology at Harvard University who also serves as editor in chief of the medical journal Dreaming. “When we’re in a dream state, the brain is processing the same things we think about during the day. But when we’re asleep, the parts of our brain that handle logic and speech are damped down. The parts that handle visuals, however, are ramped up.”
Current events outside of trauma can also impact our dreams, with one 2007 study finding that between 1956 and 2000, there was a significant increase in the percentage of people who reported flying in dreams, a possible reflection of the increase in air travel during the same period.
But the pandemic is the first reported upwelling of dreams that occurred on a global scale, impacting every coroner of the world simultaneously.
In order to understand the impact that the disease might have on our brains and subconsciousness, it helps to understand where our dreams come from, and what they mean.
Dream research remains as mysterious as dark matter, quantum entanglement or those things hiding at the bottom of the Marianas Trench.
Dreams tend to be presented in a linear format that last anywhere between 5 and 20 minutes. Although 95% of dreams are forgotten by the time a person gets out of bed, everyone dreams on average between 4 and 6 times per night.
There's a few theories on what causes dreams, ranging from representations of our unconscious desires and a wish to consolidate and process information gathered throughout the day. But whether dreams are a working form of psychotherapy or an interpretation of random signals from the brain and body during sleep, they might also provide several important functions.
These can include memory processing - where the brain consolidates learning and memory tasks to support and record waking consciousness - the development of cognitive capabilities, or even just offering a unique state of consciousness that incorporates and processes experiences of the past, present and future.
We’re almost certain that dreams take place during the Rapid Eye Movement, or REM part of the sleep cycle, a mere 20-25% of the 8 hours we normally sleep. This phase occurs following reduced muscle activity and the appearance of delta waves in the brain. Breathing becomes shallow, eyes jerk rapidly in various directions, limb muscles become temporarily paralyzed, heart rate increases and blood pressure rises, which, if you weren’t asleep, might be a terrifying experience on its own.
But whether it’s dreams, nightmares, or lucid dreaming, analysis of dreams are often broken into two distinct categories.
Neuroscientists focus on the structures involved in dream production, like organization and narratability, while psychoanalysts tends to concentrate on the meaning of the dreams, placing them into the context of relationships.
Freud placed emphasis on repression, maintaining that undesirable memories could become suppressed in the mind, and dreams can allow the individual to ease repression through experience. Recent studies have even confirmed some of Freud's speculations, with one study having found that REM sleep can invoke certain suppressed memories, making them more accessible for retrieval.
The study, published in the Journal of Sleep Research, asked volunteers to suppress an unwanted thought 5 minutes prior to sleep, and the results showed overwhelmingly that there were increased dreams about the unwanted thought as well as a tendency to have more distressing dreams, indicating suppression may lead to significantly increased symptoms of distress.
Fortunately, there are several studies underway that propose potential solutions to brain fog and other cognitive challenges that have resulted from COVID-19 infections, many of which revolve around the concept or neuroplasticity, or the ability for neural networks in the brain to change, adapt and strengthen, much like a muscle in the body that is trained and exercised.
“The brain’s ability to bounce back from injury is what neuroplasticity is, and I’ve worked with people in our rehab clinic who have had brain tumors or suffer the effects of surgery or radiation on the brain, and people who have had West Nile, HIV and meningitis,” Tom Bergquist, clinical neuropsychologist at Mayo Clinic in Rochester, MN, told WebMD. “There’s not a week that foes by that I don’t see someone recovering from COVID-19.”
One approach being used as part of the Mayo Clinic study involves errorless learning, an exercise similar to flashcards, where people repeat memorized information until they succeed without error. The repetition helps rebuild memory and cognitive skills associated with brain fog.
The technique has been used before to treat patients with long-term cognitive issues following Lyme disease infection. Many symptoms experienced during post-treatment Lyme disease syndrome overlap with long term COVID infections, including brain fog, joint pain and sensory related issues.
“Essentially, what we believe is happening here, is the brain has learned that these symptoms are life-threatening - because, in fact, they can be,” said Ben Ahrens, co-founder and CEO or re-origin, a company conducting studies using neuroplasticity to treat lingering Lyme disease symptoms. “The brain's one job is to protect the body, and once it's learned to associate these symptoms with that potentially very dangerous pathogen, even after it's gone, things like a normal headache can trigger an immune cascade.”
Additional studies are taking place at the University of Alabama at Birmingham to test a technique called ‘shaping,’ which requires a person to carry out their function of impaired use - like remembering household tasks that are previously forgotten - and going over them again and again. After several weeks of seemingly simple task repetition, researchers recorded an increase in the brain’s gray matter.
Even 35 hours of therapy have shown improvements, with those continuing over a six month period reporting a nearly 100% improvement.
The takeaway is the brain is an ever-changing and adaptable part of the body that can be worked out like any other muscle. And even if the instances of nightmares have collectively increased, the more we understand the brain, the better chance we have to repair any collective trauma experienced. As Arthur C. Clarke puts it: “Magic is just science that we don’t understand yet.”