Why do we have nightmares? What, according to science, causes bad dreams and nightmares

Dreams and nightmares are a topic that has fascinated and puzzled scientists for centuries.

Although they have been the subject of extensive research, no one knows exactly why we dream, and opinions differ as to what dreams might mean.

Dreams range from the mundane – most of us have had dreams, we got up and got ready to go to work only to wake up and realize we have to do it again – to the surreal, while nightmares can affect both children and children. adults. equally. can wake up adults. in a cold sweat.

Here’s what experts can tell us about why we have nightmares and when they’re most likely.

What are nightmares?

According to Harvard Medical School, nightmares are simply dreams that evoke a strong but unpleasant emotional response.

Most of the dreams and nightmares we remember occur during REM sleep—a phase of sleep characterized by rapid eye movements, irregular heartbeats, and rapid breathing—which makes up about 20 percent of our nightly sleep. Every night we have four or five short periods of REM sleep.

Nightmares most often occur during sleep, when REM intervals are lengthened, which usually occurs in the middle of sleep.

Harvard Medical School explains: “As we prepare to wake up, memories begin to coalesce and become stronger. We dream when we come out of REM sleep. Because we tend to dream at the border between sleep and wakefulness, we recall the images we imagined in our dreams, including vivid, often frightening images that occur during nightmares.

Researchers disagree on why we actually dream. Neurologist Sigmund Freud believed that dreams are a way to free the mind from repressed thoughts and feelings, while some believe that they do not make sense at all.

Why do we have nightmares?

There are many reasons why nightmares can occur, such as stress, anxiety, irregular sleep patterns, medications, mental disorders, and even reading a scary book or watching a horror movie before bed.

One of the most well-studied causes of nightmares is post-traumatic stress disorder (PTSD). Nightmares are one of the criteria for diagnosing the disorder.

A University of Pittsburgh School of Medicine study published in 2009. Sleep medicine clinicsfound that 80% of people with post-traumatic stress disorder regularly have nightmares.

The U.S. Department of Veterans Affairs National Post-Traumatic Stress Disorder Center reports that about half of people who have nightmares after a traumatic event experience trauma-repeating nightmares, while people with PTSD are significantly more likely to accurately repeat the traumatic event.

In addition to PTSD, nightmares are more common in children than adults.

Dr Deirdre Barrett, Clinical Assistant Professor of Psychology at the Cambridge Health Alliance and Editor trauma and dreamsShe explains, “We think some of that may be evolutionary. Children are smaller and more vulnerable to many more threats than adults. Nightmares may partly reflect this vulnerability.”