How You Can Scream, Eat, Have Sex, Even Kill Someone Without Knowing It
Night terrors, sleepwalking and other parasomnias
Your child wakes up night after night screaming in terror. Is this a nightmare? Or she stumbles into the bathroom, but instead of using the toilet, she climbs into the shower stall and pees in the bathtub. Is she enacting her dreams, or sleepwalking? Sometimes it can seem difficult to distinguish one nocturnal disturbance from another – but there is actually a simple dividing line: stage of sleep. When a person is in Rapid-Eye Movement (REM) sleep, their actions and emotions correspond with dreaming, and they are typically immobilized. During deeper, Non-Rapid Eye Movement (NREM) sleep, the person appears to be awake because they are thrashing around and screaming, but they are in fact, deeply unconscious.
What makes it possible to appear awake and perform complex functions while still being in such a deep sleep that you have no recall of events? During sleepwalking episodes, people have been known not only to wander around the house, but also to raid the kitchen for snacks, engage in sexual activities, drive a car, even commit acts of violence. A couple of high-profile murder cases (Scott Falater and Ken Park) brought a flurry of media attention to this sleep disorder in the ‘90s, raising challenging questions about the nature of one’s state of mind during an episode. (More on this later…)
Understanding Sleep Architecture: Your Nightly Journey
Before we dive into the complexities of mind-state during somnambulism, it helps to first understand sleep’s basic structure. Sleep architecture is a step-wise nightly journey your body and mind take, with each stage serving a unique and important purpose. First, we will delineate what ideally happens in each stage, and then we can perhaps better understand the strange array of possible variations. These so-called parasomnias are mostly benign but occasionally alarming and dangerous.
The first stage of a typical nocturnal journey is NREM sleep which starts with Stage 1, the lightest sleep stage, where you're just beginning to wind down and let your mind wander. Imagine lying in bed, feeling yourself drift off but still aware of your surroundings. You might have sudden jerks where it feels like you're falling. Ideally this stage helps you relax, and can include a drifting in and out of short dream-like hypnagogic visions.
Next, you move into Stage 2, which acts like a gateway to deeper sleep. Your body temperature drops, your heart rate slows, and you become less aware of your surroundings. Think of it like your body going into a power-saving mode, much like your phone dims the screen to save battery. This stage prepares your body for the deeper, more restorative sleep to come.
Then, you enter Stages 3 and 4, often combined and called deep sleep or slow-wave sleep. Picture this stage as your body's overnight repair shop, fixing all the wear and tear from your day. During this time, your body repairs muscles and tissues, boosts immune function, and builds energy for the next day. It's the hardest stage to wake up from because your body is doing essential restorative work in a very deep state of slumber.
After completing these stages of NREM sleep, you transition into REM, the stage where most of your dreaming happens. Your brain is very active, more so in some regions than when you’re awake, and your eyes move rapidly under your eyelids. Imagine your brain as sorting through the events of your day, deciding what to keep and where to file everything. REM sleep is crucial for learning, memory, and processing emotions.
Throughout the night, you cycle through these stages multiple times, each cycle lasting about 90 minutes. You'll typically go through these cycles 4-6 times a night, depending on how long you sleep. As the night progresses, the time spent in REM sleep increases while deep sleep stages become shorter. This ensures that by morning, you've had the right balance of restorative sleep and dreaming. Understanding this journey helps you appreciate why getting a full night's sleep is so important – each stage serves a specific function. Those who cut their sleep short by getting up earlier than is optimal cut off their REM sleep and dreaming, adversely affecting mood, memory and emotional regulation.
When differentiating between the REM sleep problems like sleep paralysis, and NREM experiences like night terrors, one of the biggest clues is the time of night in which they occur. Sleepwalking and night terrors happen in the slow-wave sleep stage. The first and by far the longest slow-wave sleep phase begins early in the sleep cycle, within an hour of falling asleep, while REM is more concentrated in the second half of the night and toward morning. Another clue is the level of awareness the person experiences. If they are difficult to wake up, groggy and disoriented (if you do manage to rouse them), and have no memory of the incident, they have just been in deep, slow-wave sleep. You may have awakened them because they sounded terrified, and you want to rescue them from a nightmare. In fact, this is a night terror, a different state entirely, and it’s best to let them be.
Understanding Night Terrors
I used to go to bed with a kind of dread when we lived in a lovely heritage apartment in Vancouver. Most nights, about two hours after falling asleep, I would be startled awake by the most blood-curdling, agonizing screaming from the woman next door. Her window faced ours across a narrow alley, so it was easy to hear her wailing and shrieking, as if being murdered in her sleep. I wondered why no one would wake her up or help her. I have since learned that this would not have done much good as she was having night terrors.
Many people I’ve spoken with have had sleepwalking experiences in childhood, or with their own children, and sometimes both as it runs in families. Night terrors are fairly common, affecting 20-40% of children, compared with 2% of adults. In a typical episode, parents will put their child quietly to bed only to hear them thrashing and screaming in terror about 90 minutes later. The kids are hard to fully wake up, and if awakened are disoriented and confused. They typically have no memory of the incident in the morning.
Night terrors are often mistaken for nightmares. At a recent talk I gave about nightmares, most of the questions were actually about night terrors – from desperate parents wanting to know if there was something they could do. There are a few things to know and to do that can help. First and foremost, know that they are generally benign and kids usually grow out of them.
Who Has Night Terrors?
Before I get into some of the ways you can help your child with their night terrors, it helps to understand what they are, who has them and why. A thorough survey of the literature suggests that although the exact cause is not well understood, genetic, developmental, environmental, psychological and organic factors can all play a part.
Night terrors most common in early childhood. A longitudinal study (Petit et al., 2015) of 1,940 children from Quebec found that 34% of children aged 18 months experience night terrors, 13% at age 5, and 5% at age 13. A recent review (Leung et al., 2020) found the peak may be later, at age 5-7 years. Either way, sleep terrors typically start at a very young age and stop at adolescence. It’s rare that the condition continues into adulthood – although for some it can switch to sleepwalking, which is a similar condition in many ways.
Sleep terrors and sleepwalking are more common under the following circumstances: sleep deprivation, going to bed with a full bladder, emotional stress, anxiety (including separation anxiety), bullying, a noisy sleeping environment and excessive alcohol or caffeine intake. Other factors associated with this parasomnia include: febrile illness (unexplained fever), ADHD, autism, epilepsy, sleep apnea and PTSD. Some medications, especially those that are sedative, can lead to night terrors because they increase the duration of non-REM, the deep sleep stage in which these episodes occur.
It bears repeating the while night terrors are very distressing and can disrupt sleep for both children and their parents, they are not considered dangerous. They warrant clinical attention only if they are severe enough to disrupt daytime functioning. If you are considering consulting a doctor, keep a sleep diary and track BEARS. Not the big furry animal, but the 5-item assessment tool for children with sleep problems (Owens & Dalzell, 2005):
o B: bedtime issues
o E: excessive daytime sleepiness
o A: night awakenings
o R: regularity and duration of sleep
o S: snoring
What Are Night Terrors?
In a typical episode, the child will sit bolt upright or even jump out of bed, heart racing, screaming in terror. They may speak, but what they say will be confused and incoherent because although they appear to be awake, they are in a hybrid sleep-wake state. They will be difficult to wake fully. Night terrors are distinguished from nightmares because they happen in the first half of the night, during NREM, and while there is plenty of sound and movement, there is little to no recall. Nightmares happen in the second half of the night, during REM, are clearly recalled in vivid detail, and there is little to no movement or vocalization.
As noted, night terrors are much more common in children. When they continue into adulthood, they look a bit different because adults remember their episodes about half the time (Castelnovo, et al., 2021). For adults, night terrors appear to be more of a dissociative experience, and can be accompanied by hallucinations.
What you can do about night terrors
While none of the suggestions below work all the time, there are a number of things you can try to reduce or even eliminate night terrors. Excellent sleep hygiene (such as regular bedtimes, limiting screen time, no food and drink before bed, especially sugar and caffeine, a dark, cool quiet bedroom, and wind-down rituals like story time) can all help reduce night terrors. Parents can also do their best to limit stresses on kids who have night terrors – things like bullying and separation anxiety should be addressed. Interestingly, psychological factors are found to be mostly associated with night terrors in teens and adults, but not young children.
Wake-up treatment. One preventative treatment that has met with some success is to wake a person up about half an hour before they would typically have an episode. If you do this for two weeks, it can break the cycle and stop it from recurring. In some cases, however, the episodes simply start occurring later in the night.
Co-sleeping. One interesting paper (Boyden, Pott & Starks, 2018) suggests that sleeping with your child stops night terrors, especially with very young children. The authors say that evolution did not design humans to sleep alone when very young and that “night terrors are the result of an environmental mismatch between evolved behaviour and the modern cultural practice of solitary sleeping.” This solution has not been empirically tested, but anecdotally, it appears to work for many.
The above measures are helpful in preventing or reducing the frequency of episodes. During an episode, there is another set of steps you can take:
1. Stay Calm: It can be very upsetting to see your child in such a state, but it's important to remain calm. Your calm presence can help soothe them indirectly.
2. Ensure Safety: Make sure your child is safe and cannot hurt themselves. Gently guide them back to a lying position if they're sitting up or moving around. Remove any objects that they could knock over or hurt themselves with.
3. Avoid Waking Them: Instead of trying to wake them, speak to them in a soothing voice and offer gentle reassurances. Phrases like "You're okay, Mommy/Daddy is here" can be comforting, even if they don't seem to respond.
4. Wait It Out: Most night terrors last only a few minutes, though they can feel much longer. Stay with your child until the episode passes and they settle back into a calmer state of sleep.
5. Consult a Professional: If night terrors are frequent or particularly severe, it may be helpful to consult a pediatrician or sleep specialist for further advice and support.
The bottom line is that while night terrors can seem extreme, they are usually nothing to worry about, and can be addressed to varying degrees though sleep hygiene, limiting stress and all of the practices mentioned in this chapter. Typically, children will experience them less and less over time. To all the exhausted parents reading this, I hope this helps.
Sleepwalking and more: Sex, Violence, Binge-eating
Most of us sleep soundly, particularly in the first half of the night, and wake without worry about what might have transpired during the night. But for those with the neurological anomaly that makes them rouse more easily from deep sleep, they may have had sex, eaten a meal, wandered the neighborhood, engaged in nonsensical conversation, driven the car, even hurt or killed someone, all while sleeping.