At the height of the pandemic, a strange phenomenon occurred: people began to have strange dreams.

The effect appears to have been more pronounced in those particularly affected by the virus and in countries with strict quarantine measures. Concerns about confinement, loved ones, and personal health were suddenly mixed with other worldly thoughts, leaving many people confused upon awakening.

For people on the front lines of COVID-19, dreams turned into nightmares.

Of 114 doctors and 414 nurses working in the Chinese city of Wuhan And who participated in a study published in January 2021, more than a quarter reported having frequent nightmares.

Reports of nightmares among citizens also increased during quarantines. Young people, women, and people with anxiety or depression are most at risk.

But for people researching trauma, the increase in nightmares came as no surprise.

For those on the front lines of responding to COVID-19, such as doctors and nurses in Wuhan, 2020 was a period of “chronic stress,” he says. Rachelle ho, a PhD candidate at McMaster University in Canada.

Long periods of stress that last for months or years and affect entire populations are quite rare, comparable only to wars in recent historysays Ho.

But we know that chronic stress has a significant effect on our cognitive function.

People who live under regular duress are more likely to have nightmares.

A study that analyzed 10 to 12-year-old schoolchildren in the Gaza Strip found that more than half experienced frequent nightmares. On average, they had them more than four nights a week. Children are particularly susceptible, Ho says, because their brains are still developing.

  • What the databases that analyze the dreams of the world say about us

While nightmares are strongly linked to a number of mental illnesses, some vivid dreams help us process the emotions of the day before, he says. Joanne Davis, a clinical psychologist at the University of Tulsa, in the United States.

Understanding why bad dreams turn into nightmares helps to treat people who have suffered trauma.

How bad dreams protect us

Psychologists like Davis are beginning to unravel the links between our dreams, psychological disorders, and their importance in keeping us emotionally stable when we are in good health.

While we sleep, we organize and archive our memories of the day before and dust and rearrange our old memories.

This is believed to happen during sleep, but it is in the stage of rapid eye movement (REM) (just before we wake up or when we drift into sleep) when we store our most emotional memories. These emotionally charged memories become the plot of our dreams.

A bad dream can help people during the day.

The “sleep to forget, sleep to remember” hypothesis indicates that REM sleep strengthens emotional memories, stores them safely, and also helps attenuate our emotional reactions after those events.

  • Nightmare disorder: why the coronavirus pandemic is affecting our sleep (and how you can prevent it)

For example, if your boss yells at you and you dream about it later that night, the next time you see your boss you will feel less upset by that incident.

That our dreams train us to control our emotions is an intriguing idea, but what evidence is there?

Remove the emotional tag

When our brain is in REM sleep, both the hippocampus and the amygdala are very active. The first is the part of our brain that orders and stores memories; the second is the part that helps us process emotions.

This has led researchers to suggest that vivid, emotional, and memorable dreams during REM are manifestations that our brains store memories and “remove the emotional tag,” Ho says. The analogy of removing an emotional tag is widely used in sleep psychology.

After a bad dream, the area of ​​the brain that prepares us to be afraid is more effective, as if the dream trains us for this situation.

The longer people had been afraid during their dreams, the less their emotional centers were activated when they were shown stressful images. However, it is one thing to be better prepared to look at distressing photos and another to be prepared for your boss to yell at you in reality.

Our tonsil may need this processing period to restore itself before the next day. Perhaps getting rid of the emotional baggage of the day before overnight allows us to start from scratch in the morning.

Studies in stressed workers show that our level of cortisol, the hormone that helps regulate our response to stress, is highest in the morning, which means that we can react better to stress early on.

Although cortisol is produced elsewhere, our amygdala is the one that detects stressful situations.

During the REM phase, our brain produces slow, low-frequency theta waves in the hippocampus, amygdala, and neocortex (we also produce theta waves while we are awake, but they are particularly characteristic of REM sleep).

  • 6 tips for going through isolation due to the coronavirus with your partner (without ending up separated)

Studies in rats, in which some were subjected to stressful tasks, found that those rats that had to do something unpleasant had more REM periods and increased theta waves during REM in the following night’s sleep.

Daniela Popa, a neuroscientist at the Institute of Biology at the École Normale Supérieure in Paris and the author of one such stress-inducing study, went on to show that the same areas of the brain involved in processing emotional events in dreams were stimulated again if rats were it presented the same stressor to them.

That could mean REM sleep and theta activity are uniquely involved in the long-term storage and processing of bad memories.

But Popa points out that it is difficult to look for non-emotional memory storage in rats, since it is difficult to know what they are thinking.

How are nightmares treated?

It is one thing to have the occasional bad beneficial sleep and another completely to have chronic nightmares.

“With the nightmares, the process seems to be stuck,” Davis says. “Your brain may intend to process this emotional event, but it gets stuck because you wake up in the middle of it, so you don’t see it at all.”

“Once you have nightmares for a long period of time, they become like habits,” says Davis, who cites that some of the patients he sees have lived with chronic nightmares for decades before seeking help.

“You worry about having a nightmare, maybe you avoid sleeping or try to sleep as quickly as possible, so you self-medicate for the night.”

As a clinical psychologist, Davis treats trauma survivors, which can include veterans, active duty personnel, children, or people with conditions such as bipolar disorder. And for this use the exposure, relaxation, and prescription therapy (ERRT).

In ERRT, the patient writes his nightmare exactly as he remembers it (exposition, which works particularly well with people who have anxiety, Davis says) or he writes his nightmare with a new ending (prescription).

With rescription, the patient does not necessarily begin to incorporate the new ending into their dream, but “what tends to happen is that they just don’t have the nightmare or they still have it but it is not as powerful or as confusing: it just decreases in frequency. and disappears. ”

“It’s almost as if solving the problem during the day solves the need to relive it over and over again at night,” he says.

“Fix the nightmares”

Davis understands that the importance of treating nightmares is more than just a symptom of a larger problem. “Just a few decades ago, our field viewed nightmares as a symptom of post-traumatic stress disorder,” he says.

“But there has been a paradigm shift to thinking of nightmares as the hallmark of many of the problems. If you fix the nightmares first, you can fix the other things that are going on, like depression and substance abuse.”

Davis says it’s important to view nightmares as an early indicator of future trouble. Emotional dreams sometimes occur at night after a significant event and sometimes five to seven days later.

Penny Lewis, a professor of psychology at the University of Cardiff, Wales, and her colleagues propose that we store everyday memories immediately after they happen, but that when it comes to things of deep personal importance they emerge later in the dream.

Teaching people with chronic nightmares to control them through lucid dreaming also appears to reduce their frequency.

This type of treatment is called imaging rehearsal therapy (IRT) and has been successful in small groups, although the researchers in this particular study are unclear exactly how it works, and these studies are also often unnatural.

In all cases, these treatments focus on finding ways to make sure patients sleep through the night without waking up, giving their brains the rest they need to improve their cognitive function.

The challenges of the pandemic

While our understanding of the cause and treatment of nightmares has improved considerably in recent years, the strict quarantines since the onset of the pandemic posed new challenges for people undergoing treatment.

In a small survey of French patients who had undergone IRT to treat the cause of their recurring nightmares, the pandemic caused a relapse in two-thirds of them.

All of these patients had been able to successfully reduce the onset of their nightmares (on average from almost every night to about twice a week) thanks to the therapy.

But in 2020, four years after they underwent therapy, most reported an average of 19 nightmares per month.

Benjamin Putois, a neuroscientist at the University of Lyon, and his co-authors Caroline Sierro and Wendy Leslie, write that during the crisis “the increased frequency of nightmares could be interpreted not only as the reactivation of traumatic memories, but also as a greater need for emotional regulation“.

So the next time you have a bad night’s sleep, think of it as the way your brain regulates emotions overcoming the stresses of the day before.

Davis says you should only worry if the nightmares are regular or if they start to affect your health. But for most people, a bad dream can be a good thing.

Read the original story in English on BBC Future.

Now you can receive notifications from BBC News Mundo. Download our app and activate them so you don’t miss our best content.

  • Do you already know our YouTube channel? Subscribe!

Read more