Night Terrors and Other Parasomnias in Adults

A message came in recently from someone who'd noticed a night terror pattern in an adult and couldn't find much written for anyone past childhood. That's a fair complaint. Almost everything published on night terrors is written for parents of young kids, and adults dealing with the same thing are left to piece it together from forum posts and pediatric pamphlets. This is written for them, and for the caregivers of people with brain injury, where the picture changes considerably.

What a Parasomnia Actually Is

A parasomnia is an unusual behavior that occurs during sleep or in the transition into or out of it. Night terrors are one type. Sleepwalking and confusional arousals are others. They're grouped together because they all happen in a similar window, when the brain is caught between sleep stages and doesn't fully complete the transition.

A night terror is not a nightmare, and the difference matters. A nightmare happens during REM sleep, and the person wakes up remembering it. A night terror happens during non-REM sleep, typically in the first third of the night, and the person often doesn't wake up fully. They may sit up, scream, thrash, or get out of bed, and they usually have no memory of it the next morning.

How Common This Actually Is

In the general adult population, night terrors are uncommon. A representative telephone survey of nearly 5,000 adults in the United Kingdom found a prevalence of 2.2 percent, with a 95 percent confidence interval of 1.8 to 2.6 percent (Ohayon, Guilleminault & Priest, 1999, Journal of Clinical Psychiatry). The same study found sleepwalking in 2.0 percent and confusional arousals in 4.2 percent, and all three declined significantly with age.

What Actually Triggers It

Well-designed research on what triggers night terrors in adults is limited, and it's worth saying so plainly rather than reciting a tidy list that oversells what's known. What holds up is narrower than most articles suggest. Alcohol use disorder is associated with a meaningfully higher rate of sleep terror disorder, 20 to 36 percent in one clinical review, compared to roughly 1 to 7 percent in adults generally (a case report and literature review, PMC10413013). Sleep deprivation is also a plausible factor, grounded in basic, well-established sleep physiology rather than a study of adults with night terrors specifically. Missing sleep pushes the brain into a deeper, more intense stretch of slow-wave sleep the following night, and slow-wave sleep is exactly where night terrors happen. Beyond those two, claims about stress, fever, or medications as adult triggers circulate widely online, but they trace back to pediatric research or general patient-education pages rather than adult-specific studies, so they're left out here.

Where the Picture Changes: Brain Injury

In a study of 60 adults evaluated at a sleep center for complaints following chronic traumatic brain injury, parasomnia was the presenting complaint in 25 percent, and REM sleep behavior disorder was the most frequently identified type, confirmed on polysomnography in 13 percent of those tested (Verma, Anand & Verma, 2007, Journal of Clinical Sleep Medicine). That's a group that had already sought help for sleep problems, not a random sample of everyone with a brain injury, and that distinction matters. But it's still a real, documented jump from the general population's 2.2 percent, and it points to something structural, not incidental.

The mechanism traces back to the same brain structures responsible for regulating sleep-stage transitions, particularly regions in the brainstem and the arousal system that governs how completely the brain moves from one sleep stage to the next. A brain injury can damage the coordination of that system without damaging the ability to sleep altogether, which is part of why a caregiver might see screaming, thrashing, or an attempt to get up and walk, in a loved one who otherwise appears to sleep normally most nights.

What an Episode Actually Looks Like, and What to Do

During an episode, the person isn't fully conscious and typically won't respond to being spoken to in a way that resolves it faster. A review of 32 documented medical and legal cases found that violent behavior during these episodes was associated with direct physical contact or close proximity to another person in 81 percent of sleep terror cases and 100 percent of confusional arousal cases (Pressman, 2007, Sleep). That figure describes a small, non-random set of cases involving violence specifically, not a general prediction, and the overwhelming majority of episodes involve no aggression at all. Still, the safer practical approach is to protect the person from injury, clear anything they could trip on or strike, and avoid grabbing or restraining them unless there's an immediate safety risk. Most episodes resolve within several minutes on their own.

When to Get a Formal Evaluation

If episodes are frequent, involve injury, or are new since a brain injury, that's a conversation for a sleep specialist, not a guess made at home. A sleep study can distinguish between night terrors, REM sleep behavior disorder, and other parasomnias, which matters because the treatment approach differs by type. Whether you came to this because you're dealing with an isolated adult night terror with no brain injury involved, or because you're watching someone you love go through this regularly since their injury, the core answer is the same: this is a real, documented phenomenon, not something to be embarrassed about or dismissed, and when it's frequent enough to disrupt real sleep, for either of you, it's worth a formal evaluation rather than years of guessing.

Sources

1. Ohayon, M.M., Guilleminault, C., Priest, R.G. (1999). Night terrors, sleepwalking, and confusional arousals in the general population. Journal of Clinical Psychiatry, 60(4), 268-276. PMID 10221293.
2. A Rare Case of Sleep Terror Disorder in an Adult With Chronic Alcohol Abuse: A Case Report and Literature Review. Cureus (via PMC). PMC10413013.
3. Verma, A., Anand, V., Verma, N.P. (2007). Sleep disorders in chronic traumatic brain injury. Journal of Clinical Sleep Medicine, 3(4), 357-362. PMID 17694723.
4. Pressman, M.R. (2007). Disorders of arousal from sleep and violent behavior: the role of physical contact and proximity. Sleep, 30(8), 1039-1047. PMID 17702274.