Night TerrorsYou wake up in the middle of the night gripped by a feeling of dread, the covers tangled around you as though you’ve been trying to fight something off in your sleep, but you can’t remember the bad dream that woke you. If this has ever happened to you, night terrors could be to blame. Also called sleep terrors, incubus attacks, and pavor nocturnus, night terrors are a kind of parasomnia disorder characterized by feelings of dread or terror which occur in deep (Stage 3 or 4) non-REM (NREM) sleep. Unlike the much more common nightmares– dreams with scary or distressing content–night terrors usually have no dream content because they occur in a deeper stage of sleep in which the brain doesn’t dream. However, night terrors can be just as or more disruptive because they interfere with restful sleep for both sufferers and their family members, and can make people feel exhausted the next day.

Parasomnia disorders are a category of sleep disorder involving abnormal or unnatural movements, emotions, perceptions and dreams that occur while falling asleep, sleeping, between different sleep stages, and when waking from sleep. Parasomnias seem to be triggered in some people when the brain is partially aroused from sleep, such as during the transition between sleep and wakefulness or between the REM (rapid eye movement) and NREM stages of sleep. Besides night terrors, some other parasomnias are sleepwalking (somnambulism), restless leg syndrome, teeth-grinding, and confusional arousals that cause a person to wake in distress, often thrashing their limbs in bed.

Even in kids, night terrors are far less common than nightmares: about 1% to 6% of children, and 1% of adults, will have a night terror sometime in their lives; for adults, people in the 20 to 30 age bracket are most likely to experience night terrors. Sleep researchers who’ve studied the prevalence of night terrors cross-culturally have observed no significant difference in their rate of occurrence across cultures, although different cultures may assign different meanings and significance to this parasomnia disorder.

Observers to a night terror attest that sufferers may thrash and scream in their sleep, eventually seeming to wake abruptly with a look of terror on their faces. The sufferer may not recognize the people around him or her, and may seem to be fighting off an invisible threat; in extreme cases, sleep terror sufferers may get up and run around the room! Lab experiments that measure a person’s physiological condition during sleep have discovered that subjects often exhibit increased muscle tone, perspiration, rapid breathing and tachycardia (elevated heart rate) during a night terror episode. Most interestingly, unlike with a nightmare where the person often vividly remembers the content of the dream, sufferers often don’t remember anything about their night terrors after waking up.

It’s still unclear what causes night terrors in children and adults. There’s probably a genetic component: people are more likely to suffer night terrors if one of their first-degree relatives— like a parent or sibling—also experienced them. In adults, night terrors are sometimes correlated with conditions like borderline personality disorder and anxiety-linked disorders such as PTSD (post-traumatic stress disorder) and GAD (generalized anxiety disorder). Furthermore, some adult night terror sufferers may share characteristics with people who suffer from depression, such as the “inhibition of aggression, self-directed anger, passivity, anxiety, impaired memory, and the ability to ignore pain” (Carranza 2004). However, while night terrors can often accompany mental disorders, there’s still little evidence to indicate that night terrors in themselves are a sign of an underlying psychological disorder.

Overtiredness and poor quality of sleep seem to be far and away the greatest causes of night terrors in adults. Conditions that result in an altered quality of sleep, such as narcolepsy, sleep apnea, fever and chronic sleep deprivation can all feed into a higher incidence of adult night terrors. Some sleep researchers have also pegged hypoglycemia (low blood sugar) as a potential cause of night terrors, because it spurs the body to secrete adrenaline, resulting in a lighter, more superficial sleep.

Given their probable cause, it isn’t surprising that most treatments for night terrors focus on helping the sufferer achieve restful sleep. It’s pretty rare for people to seek a clinical diagnosis of night terrors, as the problem can often be treated at home with relaxation techniques and herbs that promote a deeper, more restful sleep. However, if someone does want to get a specific diagnosis of night terrors, they’ll usually be asked to stay overnight in a sleep lab where technicians can monitor their heart rate, muscle tone, eye and limb movements and other physiological data for sleep terror symptoms. There are a range of cognitive therapies, including relaxation therapy and hypnosis, that can be helpful in reducing the incidence of night terrors in adults; in children, giving them a dose of reassurance during the day and before bed is often enough to curb night terrors, which generally go away on their own as children age. Rarely, sedative medications like benzodiazepines may also be used to stop night terrors, but most physicians consider this a tool of last resort: gentler cognitive therapies often work just as well, and some sleep medications have actually been linked to a higher incidence of parasomnias they’re supposed to treat, especially sleepwalking.

Like nightmares, night terrors are no fun for the sufferer, or for family members who may feel they’re powerless to help. Fortunately, some of the same techniques that work to stop nightmares can also help decrease the incidence of night terrors and make for a deeper and ultimately more fulfilling quality of sleep.

Sources: Carranza C.R. and J.R. Dill. Banishing Night Terrors and Nightmares: A Breakthrough Program to Heal the Traumas that Shatter Peaceful Sleep. New York, Kensington Publishing Corp.: 2004.