Prevalence of Different Parasomnias in the General Population

Original Article Prevalence of Different Parasomnias in the General Population

Authors: Bjørn Bjorvatn, Janne Grønli, Ståle Pallesen
Affiliations:

  • Department of Public Health and Primary Health Care, University of Bergen, Norway
  • Norwegian Competence Center for Sleep Disorders, Haukeland University Hospital, Norway
  • Department of Biological and Medical Psychology, University of Bergen, Norway
  • Department of Psychosocial Science, University of Bergen, Norway

Article Information

  • Received: 18 March 2010
  • Revised: 30 June 2010
  • Accepted: 13 July 2010
  • Keywords: Sleep talking, confusional arousal, sleep terror, sleep violence, sexsomnia, nightmare, dream enactment, sleep-related eating

Abstract

  • Objective:

    • To estimate lifetime and current prevalence of various parasomnias in the general population.
    • To examine relationships between different parasomnias, gender, depressive mood, symptoms of sleep apnea, insomnia, and restless legs.
    • To assess the prevalence of multiple parasomnias.

  • Methods:

    • Conducted a population-based cross-sectional study with 1000 randomly selected adults (51% female) via telephone interviews in Norway.

  • Results:

    • Lifetime prevalence of parasomnias varies between 4% to 67%.
    • Detailed findings include:
    • Sleepwalking: Lifetime 22.4%, Current 1.7%.
    • Sleep talking: Lifetime 66.8%, Current 17.7%.
    • Confusional arousal: Lifetime 18.5%, Current 6.9%.
    • Sleep terror: Lifetime 10.4%, Current 2.7%.
    • Injuring self during sleep: Lifetime 4.3%, Current 0.9%.
    • Injuring someone else during sleep: Lifetime 3.8%, Current 0.4%.
    • Sexual acts during sleep: Lifetime 7.1%, Current 2.7%.
    • Nightmare: Lifetime 66.2%, Current 19.4%.
    • Dream enactment: Lifetime 15.0%, Current 5.0%.
    • Sleep-related groaning: Lifetime 31.3%, Current 13.5%.
    • Sleep-related eating: Lifetime 4.5%, Current 2.2%.
    • Depressive mood linked to increased frequency in confusional arousal, sleep terror, sleep-related injury, and nightmares.
    • About 12% reported experiencing five or more parasomnias.

  • Conclusions:

    • The study reveals high prevalence of several parasomnias in the general population. Finds require cautious interpretation due to methodological limitations such as low response rate and reliance on single questions.

1. Introduction

  • Definition: Parasomnias are undesirable behaviors/events (e.g., sleepwalking, sexsomnia) occurring during sleep onset, sleep, or arousals from sleep, indicative of central nervous system activation.
Types of Parasomnias

  • Divided into three categories:

    • Disorders of Arousal (NREM Sleep):
    • Include sleepwalking, confusional arousal, and sleep terror.
    • Common in children but also prevalent in adults.
    • Parasomnias Associated with REM Sleep:
    • Include nightmare disorder and REM sleep behavior disorder (RBD).
    • Other Parasomnias:
    • Not associated with specific sleep stages include sleep-related eating, exploding head syndrome, hallucinatory experiences, etc.

  • Diagnosis:

    • Based on subjective reports by individuals or caregivers. RBD requires polysomnographic documentation.
    • Many parasomnias occur early during sleep and are typically followed by complete or partial amnesia.
Overlap and Relationships
  • Multiple parasomnias may occur concurrently (e.g., confusional arousal and sleep terror) and may be challenging to distinguish between different types.
  • Parasomnia Overlap Disorder:
    • Diagnosed when RBD occurs alongside NREM parasomnias.

2. Methods

2.1 Procedure
  • Data was gathered through telephone interviews utilizing the 'next birthday technique' to randomly select participants, reducing selection bias.
  • Total of 3940 contacted, with a refusal rate of 25.4% resulting in 1000 participants completing the study.
2.2 Participants
  • Demographics:
    • Sample consisted of 51% females with a mean age of 47.0 years (SD = 17.7, range 18-96).
2.3 Material
  • Participants were assessed for lifetime prevalence of various parasomnias posed as single questions and then given a frequency scale regarding their occurrences in the last 3 months.
2.4 Statistics
  • Data analysis performed using SPSS version 15.0, addressing gender differences, prevalence, and relationships among symptoms. Significance level set at 0.05.

3. Results

Lifetime Prevalence
  • Lifetime prevalence of different parasomnias:
    • Varies from about 4% to 67% with current prevalence generally lower.
    • Average rates reported in Table 2 (see detailed data previous).
Gender Differences
  • Differences observed include:
    • Males: Higher rates of injury during sleep (5.7% vs. 2.9%, p = 0.031)
    • Females: Increased nightmare prevalence (72% vs. 61%, p < 0.0005)
    • No other significant gender differences found.
Depressive Mood Correlation
  • Depressive mood reported in 5.5% of respondents, correlating with increased parasomnia prevalence across several types including confusional arousal and nightmares.
Sleep Disorder Symptoms
  • Sleep Apnea:
    • Reported by 2.9% of participants; higher prevalence of sleep-related groaning in those with symptoms (52% vs. 31%, p = 0.016).
  • Insomnia:
    • Reported by 24.7% of participants; increased rates of confusional arousal and sleep terror noted in this group.
  • Restless Legs:
    • Reported by 9.9%; increased prevalence of confusional arousal observed among affected individuals.
Number of Parasomnias Reported
  • 9.8% reported no lifetime parasomnia; many individuals reported 1-3 parasomnias, while 12.1% reported five or more.

4. Discussion

  • This study addresses the prevalence of parasomnias, revealing high occurrence rates and backing findings from previous research.
  • Reporting injuries during sleep (self/others) is comparatively higher in this study than previous studies in the UK and among psychiatric patients.
  • Gender differences in the prevalence of nightmares and sleep violence have been highlighted, aligning with earlier research findings.
  • Findings suggest depressive mood impacts parasomnia frequency deeply, linking mental states with sleep disorders.
  • Limitations of the study include low response rate (25.4%) and potential recall bias affecting lifetime prevalence reporting, necessitating cautious interpretation of results.

Limitations

  • Low response rate may affect representativeness; nuances in questionnaire wording may lead to discrepancies in reported prevalence and recall bias is notable.
  • Sample characteristics aligning with known general population data suggest some degree of soundness to findings despite limitations.

Conflict of Interest

  • All authors declare no conflicts of interest related to the subject matter reported.

References

  • Cited works establish background on the classification of sleep disorders, previous prevalence studies, and methodologies for assessing parasomnias.