Almost everyone can recall a particularly weird nightmare they have had, ranging from being late to having an exam to being chased by a monster. They often leave us with feelings of anxiety, confusion, distress, and fear after waking up, wondering how our brains could have conjured such a narrative.
Around 85% of people report having an occasional nightmare.
Nightmares are a natural product of the emotional processing and creativity of our brains. Just like dreams, nightmares tend to occur during rapid eye movement (REM) sleep, and the more vivid and memorable nightmares happen when the REM intervals lengthen about halfway through the sleep cycle as we prepare to wake up. Nightmares are sometimes confused with night terrors, which are sudden reactions that may happen during the transition between the deepest stages of non-REM sleep to REM sleep. A person can feel on edge after waking up, but unlike nightmares, there is no story or image to associate with the feeling.
There are a variety of factors that can cause nightmares. Michael Schredl, a sleep researcher at the Central Institute of Mental Health in Germany, found that daily stress is a strong contributor to nightmares. Generally, nightmares reflect what people are experiencing in real life, so worries about academics, jobs, or personal relationships are likely to manifest while sleeping. Nightmares can also be a consequence of an irregular sleep schedule due to mental disorders, like insomnia, or medications. Schredl also theorizes that nightmares may be a sign of our brains reinforcing the social code we follow. In a nightmare, you can either experience aggression, or you can be the aggressor, which both induce negative feelings. This experience can lead us to understand what actions have good and bad consequences and to apply that knowledge in real-life situations.
It’s normal to have nightmares every so often. The American Society of Sleep Medicine found that around 85% of people report having an occasional nightmare. However, some groups are more affected than others. Nightmares are more typical in children than adults because they are overall more vulnerable to threats and feelings of fear. Experiencing frequent nightmares as an adult may originate from trauma experienced during the “infantile amnesia” period of childhood, which lasts from birth to around three-and-a-half years old. At this stage, no lasting memories are formed unless the child encounters significant trauma that disrupts this period, which is a factor in the Stress Acceleration Hypothesis (SAH).
SAH encompasses the idea that early hardships can speed up the development of how to manage fear and crises, according to a paper by Tore Nielsen at the University of Montreal. This coping mechanism is helpful in the short term but can lead to nightmares and other issues later in life. The trauma experienced does not have to be severe, either. A common instance is the birth of a sibling because it takes away the sole attention and care of the parents from the first child. Nielsen reported that firstborn children have nightmares more than twice as frequently as the youngest child, regardless of other factors.
Nightmares may be a sign of our brains reinforcing the social code we follow.
Most notably, chronic nightmares are a prominent symptom of post-traumatic stress disorder (PTSD). In a study by Brant Hasler and Anne Germain at the University of Pittsburgh School of Medicine, 80% of people with PTSD reported having frequent nightmares. Post-traumatic nightmares draw from the source of trauma and often manifest as exact replays of the related incident. These nightmares can be especially impactful and graphic because the areas of the brain connected to the fear response, such as the amygdala, are overwhelmed due to hypersensitivity.
Several treatments exist for those who are more prone to nightmares. Stress management is an effective manner of reducing daily stressors that might plague nightmares. More serious treatments involve psychological therapy, especially for people dealing with PTSD. Image rehearsal therapy is a cognitive therapy that specifically targets repeated nightmares. People are asked to recall and record what they experience in their nightmares, and then they rewrite it with a more positive ending. Before they sleep, they rehearse the new version to shift the narrative with the goal of reducing the frequency of nightmares and the subsequent stress. There is also medication, like prazosin, that may help with PTSD-induced nightmares by lessening the level of neurochemicals in overstimulated pathways.
Nightmares are hard to escape, considering the combination of the stress in our daily lives and our overactive imaginations. The more we understand where they come from, the more we can rest easy at the end of the day.
