There’s little doubt that illnesses, diseases, disorders, and the like can be scary. Moreover, they can be quite terrifying when little is widely known about them. The parasomnia (sleep disorder) known as Night Terrors (NTs) (sometimes, Sleep Terrors) is one of these misunderstood disorders. I first heard about NTs in a grossly misleading psychology class in college. The class, Motivation and Behavior Psych, was much more closely related to neurobiology or neurochemistry—it’s the class that sparked my deep love of neuroscience.
Right. Back to the topic. NTs are often confused with nightmares. It’s pretty widely known that nightmares suck donkey testicles; they’re vivid, scary, uncomfortable, and usually leave lasting impressions upon waking. In my worst nightmare, I awoke to someone standing over me while I slept. It was so real that, when I actually woke up, I thought the person was there. I couldn’t move, I was scared to open my eyes. It was only when I realized my dogs were calmly sleeping that I knew no one else was in the room.
Vivid? Check. Terrifying? Check! Seared into my memory? Super check. Gargling on the sack of a donkey? You bet! The nightmare, Dave, not me. Seriously. NT? Absolutely not.
So, what’s the difference between NTs and nightmares, and why is it important to know? I’m glad you asked!
Differences between nightmares and NTs range from when during sleep they occur to electroencephalography (EEG) activity. The point here is, the two are fundamentally different. Nightmares, and even nightmare disorder, are “different from NT [and consist of] a lowered motor activity […] the person is not confused on waking up, remembers the nightmares in detail, and the disordered orientation immediately recovers”.² The authors of the article, “Treatment Approach to Sleep Terror: Two Case Reports,” give a robust definition of NT:
NT is classified under parasomnias characterized with sudden attacks of fear associated with the increase in autonomic signs following crying and loud shouting during the first few hours of sleep during the delta stage (associated with the NREM period). Clinically, the person wakes up screaming, scaring, or performing sudden and self-destructive acts (like jumping, running, crashing into something, harming the person beside). The person is non-responsive to the external stimulus during this period […] The person may predominantly experience cognitive impairment signs, such as disordered orientation and memory problems, confusion, and fear on waking up. In addition to these mental symptoms, somatic symptoms associated with the overstimulation of the autonomic system, such as palpitation, sweating, shaking, skin rubor, pupillary response, may appear. While adults generally cannot remember what they experienced the previous night, children can indistinctly remember their fear.²
I think that about sums it up. So, while nightmares generally occur during REM, NTs occur prior to REM, during NREM—or non-rapid eye movement. The result of two independent sleep studies stated that NT episodes “begin exclusively during [NREM] sleep, most frequently during slow-wave sleep (SWS), and should not be considered an acting-out of a dream” and that “consciousness is altered during sleepwalking/sleep terror episodes.”¹ NT is most common in children, with a prevalence of ~3-15 percent, and decreases significantly with age, although, “it seems probable that the notion of sleep terrors is largely unknown to people, therefore different types of nocturnal attacks can be reported as sleep terrors.”¹
Difficulty in obtaining more concrete statistics pertaining to NT is a big indication that NT is a misunderstood parasomnia.
What Triggers NT?
Another great question! Both genetics and environmental stimuli play a role in NT:
It is well known that sleepwalking and night terrors run in families. Based on the study of familial incidence of sleepwalking and sleep terrors proposed that sleepwalking and night terrors share a common genetic predisposition, although the clinical expression of symptoms of these parasomnias may be influenced by environmental factors.”¹
The authors of “Treatment and Approach…” explain that “the risk of occurrence [of NT] among the first-degree relatives is ten folds more compared with those with no family history of NT.”²
Cases of NT have also been reported after stressful and/or significant life events, including divorce—personal or parental—death of a loved one, changing jobs or getting let go, changing schools, etc.
Why Does This Matter?
Part of why this matters is because additional research in NT could point to treatments aside from “making bedrooms safe” for NT sufferers or being prescribed benzodiazepine, which can cause rebounds or addiction. There is, of course, another reason it would be good to be knowledgeable about NT: “NT is highly associated with schizoid, borderline and dependent personality disorder, post-traumatic stress disorder, [and] generalized anxiety disorder.”²
Which is not to say NT sufferers have those disorders. In fact, when comparing individuals with NT to individuals who only demonstrate somnambulism (sleepwalking), only a percentage of sleepwalkers had been diagnosed as psychotic:
In contrast to sleepwalkers, [individuals with NT] demonstrate higher levels of anxiety, obsessive-compulsive traits, phobias, and depression. The Minnesota Multiphasic Personality Inventory (MMPI) profile suggests an inhibition of outward expression of aggression. A psychiatric diagnosis was established in 85 percent of patients with current night terrors. Although their psychopathology was more severe than in patients with sleepwalking, none of them was diagnosed as psychotic.”¹
Knowing the difference between NT, other arousal parasomnia, and regular ole nightmares can make a difference to the individual suffering from NT. Because a significant symptom of NT is sleepwalking, and because NT sufferers have increased mobility, they could cause damage to self or others.
Personally, I feel it’s important—if you know someone who sleepwalks—to be able to distinguish between and individual with NT and one with somnambulism, you know, on account of those regular ole sleepwalks could be psychotic.
¹Szelenberger, Waldemar, Szymon Niemcewicz, and Anna Justyna Dąbrowska.
“Sleepwalking and Night Terrors: Psychopathological and Psychophysiological
Correlates.” International Review of Psychiatry 17.4 (2005): 263-70.
²Turan, Hatice Sodan, Nermin Gunduz, Aslihan Polat, and Umit Tural. “Treatment
Approach to Sleep Terror: Two Case Reports.” Noro Psikiyatri Arsivi 52.2 (2015):