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Sleep ScienceApr 9, 20269 min read

Sleepwalking & Parasomnias: Causes and What to Do

Have you ever watched a family member walk to the kitchen in the middle of the night, hold a full conversation, then return to bed with no memory of any of it? These behaviors are called parasomnias — abnormal events that occur when the brain is caught in an incomplete transition between sleep and wakefulness. Sleepwalking affects roughly 4% of adults and is far from just a childhood quirk. This article explains the full spectrum of NREM and REM parasomnias, what triggers them, how to keep sleepwalkers safe, and when treatment is needed.

Sleepwalking & Parasomnias: Causes and What to Do

TL;DR

Sleepwalking lifetime prevalence is ~6.9%; adults currently affected ~1.5% (Stallman & Kohler, 2016). NREM parasomnias are triggered by sleep deprivation, alcohol, stress, and certain medications — managing these factors prevents most episodes. REM sleep behavior disorder (RBD) is a serious neurological warning sign: over 90% of isolated RBD cases develop Parkinson's disease or dementia with Lewy bodies within 15 years.

What Are Parasomnias? NREM vs. REM Classification

Parasomnias are abnormal behaviors, experiences, or autonomic changes that occur during sleep or during transitions between sleep and wakefulness. They are not just strange dreams — they can involve actual physical movement, vocalizations, eating, and in rare cases, violent behavior. The International Classification of Sleep Disorders (ICSD-3) divides parasomnias into two major categories: NREM parasomnias and REM parasomnias.

NREM parasomnias arise from incomplete arousals out of deep slow-wave sleep (N3). Part of the brain is awake while another part remains asleep — this 'state dissociation' produces sleepwalking, confusional arousals, and sleep terrors.[5] Episodes cluster in the first third of the night (one to three hours after sleep onset), and the person typically has no memory of the event afterward.

REM parasomnias work in the opposite direction. During REM sleep, the brain normally paralyzes the limb muscles (atonia) — a safety mechanism preventing you from acting out your dreams. When this paralysis fails, dream content spills into physical action. REM sleep behavior disorder (RBD) is the defining example, occurring in the latter half of the night. For a foundation on how sleep stages work, see sleep stages explained.

Sleepwalking in Adults: Prevalence, Genetics, and Misconceptions

Sleepwalking is often dismissed as a children's problem, but adults are far from immune. A 2016 meta-analysis by Stallman and Kohler, published in PLOS One and drawing on 51 studies with a combined sample of 100,490 participants, found a lifetime prevalence of approximately 6.9% and a current 12-month adult prevalence of about 1.5%.[1]

Genetics play a powerful role. Having one parent who sleepwalks raises a child's risk to about 45%; having both parents raises it to approximately 60%.[3] The Finnish Twin Cohort found concordance for adult sleepwalking roughly 5.3 times greater in monozygotic than dizygotic twins, and genome-wide linkage analysis identified a locus at chromosome 20q12–q13.[8] This means sleepwalking is not a consequence of poor sleep habits — it is a neurobiological predisposition that becomes expressed when certain triggers are present.

One widespread myth: waking a sleepwalker is dangerous. This is false. Waking someone who is sleepwalking will not harm them. However, they may be briefly confused or startled and occasionally react defensively. In practice, gently guiding them back to bed without fully waking them is easier and less disorienting for the person.

Other NREM Parasomnias: Confusional Arousals, Sleep Talking, and Sleep-Related Eating

Sleepwalking is the most recognized NREM parasomnia, but the family is broad.

Confusional Arousals (Sleep Drunkenness)

Confusional arousals are episodes of confusion and disorientation during the transition from sleep to wakefulness, lasting from a few minutes to occasionally up to an hour. The ICSD-3 defines them by confusion, disorientation, slowed speech, and poor memory of the event. Adult prevalence ranges from about 2.9% to 4.2%, with higher rates in shift workers.[6] The person may sit up, speak incoherently, or behave strangely but rarely leaves the bed.

Sleep Talking (Somniloquy)

Sleep talking (somniloquy) can occur in both NREM and REM sleep and is one of the most common parasomnias. About 5% of adults talk in their sleep regularly. In isolation it is benign and requires no treatment. However, a sudden increase in sleep talking can signal sleep deprivation, elevated stress, or the presence of another sleep disorder.

Sleep-Related Eating Disorder (SRED)

Sleep-related eating disorder involves repeated episodes of involuntary eating during NREM sleep, with little or no memory of the event. The person may wake to find evidence of eating in the kitchen, or notice unexplained weight gain. A notable connection to zolpidem and other sedative-hypnotics has been documented — adjusting or discontinuing the medication often resolves the episodes.

REM Sleep Behavior Disorder: More Than a Nuisance

REM sleep behavior disorder (RBD) occurs when REM atonia fails, allowing dream content to translate directly into physical action. The person may shout, punch, kick, or leap from bed. Upon waking they can often recall the dream clearly — a defining contrast with NREM parasomnias where memory is absent.

What makes RBD particularly significant is its relationship to neurodegeneration. A multicenter study in Brain (2019), following 1,280 patients across 24 centers, found that approximately 30% of people with isolated RBD developed neurodegeneration within 3 years, 47% within 5 years, and 66% within 7.5 years. The 15-year conversion rate exceeds 90%.[2] Associated diagnoses include Parkinson's disease, dementia with Lewy bodies, and multiple system atrophy.

The implication is not fear but opportunity. An RBD diagnosis can occur years — sometimes decades — before overt neurodegeneration manifests, creating a window for potential neuroprotective strategies currently under clinical investigation. If you or a partner are acting out dreams physically, a referral for video polysomnography (vPSG) is strongly warranted. For vivid dream experiences that do not involve physical movement, see our guide on vivid dreams and nightmares.

"Over 90% of people with isolated RBD will develop a neurodegenerative synucleinopathy within 15 years. This is not a sleep nuisance — it is an early neurological warning signal." — Brain, 2019 multicenter study

What Triggers Parasomnias?

Understanding NREM parasomnia triggers puts much of the prevention in your hands. The main factors include the following.

  1. Sleep Deprivation Sleep deprivation triggers a surge of slow-wave rebound on recovery nights. This intensified N3 sleep destabilizes the sleep-wake transition, making NREM arousals more likely. Maintaining a consistent sleep schedule is the single most effective preventive measure.
  2. Alcohol Alcohol fragments slow-wave sleep in the first half of the night and creates a REM rebound in the second half. This disruption of N3 architecture elevates the risk of NREM arousals. For a full explanation of how alcohol reshapes your sleep, see our alcohol and sleep guide.
  3. Stress and Anxiety Chronic stress elevates cortisol through the HPA axis, lightening sleep architecture and increasing arousal frequency. Sleep anxiety amplifies this cycle further, making the transition into deep sleep unstable.
  4. Medications Sedative-hypnotics such as zolpidem, certain antidepressants, and antipsychotics have been documented as triggers. A 2017 systematic review identified 29 drugs across four classes — benzodiazepine receptor agonists, serotonergic antidepressants, antipsychotics, and beta-blockers — as possible sleepwalking triggers, with the strongest evidence for zolpidem.[4] If symptoms began or worsened after starting a new prescription, discuss it with your prescribing clinician.
  5. Obstructive Sleep Apnea (OSA) Repeated partial arousals from OSA can trigger NREM parasomnia episodes. Multiple case reports document sleepwalking resolving completely once OSA is treated with CPAP. If sleepwalking co-occurs with snoring, an OSA evaluation is a logical first step.

Safety Measures and Treatment: What Actually Works

The first step in managing parasomnias is environmental safety. Many injuries during sleepwalking episodes are preventable.

Environmental Safety

Install door and window alarms or locks on the bedroom. Add safety gates at stairways, lock away sharp objects and dangerous tools, and place soft mats near the bed to reduce fall injury. These basic measures substantially reduce the risk of serious injury during an episode.

Scheduled Awakenings

When episodes occur at predictable times each night, scheduled awakenings — gently waking the person 15 to 20 minutes before the expected episode and keeping them awake briefly — can reset the unstable arousal pattern. A systematic review of behavioral treatments for NREM parasomnias found this intervention well-supported in pediatric cases and effective in adults with regular episode timing.[7]

Pharmacotherapy

For severe cases with injury risk or those unresponsive to behavioral interventions, pharmacotherapy is indicated. Clonazepam taken one hour before bed is the most commonly used agent. Gabapentin is also used. Note that no medication is formally FDA-approved specifically for sleepwalking; all prescriptions are off-label and should be supervised by a clinician. For building a solid behavioral foundation first, see our sleep hygiene checklist.

When Should You See a Doctor?

Not every parasomnia requires medical intervention. However, the following situations warrant prompt evaluation by a sleep specialist or neurologist.

  1. Injury has occurred or is at risk Falls down stairs, episodes near windows, or waking in unexpected locations indicate the need for immediate safety measures and medical evaluation.
  2. Acting out dreams, especially in adults over 50 Punching, shouting, or leaping from bed during sleep while recalling vivid dream content raises the concern for RBD. This is especially common in men over 50 and warrants polysomnography.
  3. New onset in adulthood with no prior history New-onset parasomnias in adulthood without a childhood history can indicate an underlying cause — obstructive sleep apnea, a neurological change, or a medication effect — that warrants investigation.
  4. Frequency of more than twice per week This frequency significantly impairs quality of life and sleep quality and merits a full polysomnographic evaluation to identify underlying drivers.

Polysomnography (PSG) simultaneously records brain activity (EEG), muscle tone (EMG), eye movements, and oxygen saturation to precisely distinguish parasomnia type and identify triggers. Video PSG (vPSG) adds behavioral video recording, which is particularly valuable for differentiating RBD from NREM parasomnias.

References

  1. Stallman HM, Kohler M. Prevalence of sleepwalking: a systematic review and meta-analysis. PLOS One. 2016;11(11):e0164769. doi:10.1371/journal.pone.0164769
  2. Postuma RB, Iranzo A, Hu M, et al. Risk and predictors of dementia and parkinsonism in idiopathic REM sleep behaviour disorder: a multicentre study. Brain. 2019;142(3):744–759. doi:10.1093/brain/awz030
  3. Bhatt MH, Bhatt DL. Somnambulism. In: StatPearls. Treasure Island, FL: StatPearls Publishing; 2024. NBK559001
  4. Stallman HM, Kohler M, White J. Medication induced sleepwalking: a systematic review. Sleep Med Rev. 2018;37:105–113. doi:10.1016/j.smrv.2017.01.005
  5. Irfan M, Schenck CH, Howell MJ. NonREM disorders of arousal and related parasomnias: an updated review. Neurotherapeutics. 2021;18(1):124–139. doi:10.1007/s13311-021-01011-y
  6. Ohayon MM, Guilleminault C, Priest RG. Night terrors, sleepwalking, and confusional arousals in the general population: their frequency and relationship to other sleep and mental disorders. J Clin Psychiatry. 1999;60(4):268–276. PMID:10221293
  7. Lam SP, Zhang J, Tsoh J, et al. Behavioral and psychological treatments for NREM parasomnias: a systematic review. Sleep Med Rev. 2023;72:101854. PMC10591847
  8. Licis AK, Desruisseau DM, Yamada KA, Duntley SP, Gurnett CA. Novel genetic findings in an extended family pedigree with sleepwalking. Neurology. 2011;76(1):49–52. doi:10.1212/WNL.0b013e318203e964
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piliq Sleep Science Team

Evidence-based content grounded in sleep research and clinical data.

piliq tracks your sleep stages every night, showing you the balance of deep N3 and REM sleep. See the data behind the patterns that drive parasomnias.

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