Psychometric properties of the Disturbing Dream and Nightmare Severity Index-Korean version.
Ruda Lee, Barry Krakow, Sooyeon Suh
Journal of Clinical Sleep Medicine March 1, 2021 DOI: 10.5664/jcsm.8974 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Psychometric validation study Peer reviewed |
|---|---|
| Sample size | 674 |
| Population | Individuals aged 18 to 39, including 109 retested after 3 months; 229 reported at least one nightmare per month |
| Duration | Test-retest interval of 3 months |
| Measures | Disturbing Dream and Nightmare Severity Index (DDNSI), Nightmare Effects Survey |
| Topics | Dreaming |
| Keywords | Humans Factor analysis, statistical Reproducibility of results Dreams Psychometrics Adolescent Young adult Republic of korea Surveys and questionnaires Sleep disorders Psychometric properties |
| Key points | The Disturbing Dream and Nightmare Severity Index showed high internal consistency (Cronbach's alpha = .920 overall; .755 in those with more than one nightmare per month), three-month test-retest reliability of .705, and convergent validity with the Nightmare Effects Survey (r = .638). Exploratory factor analysis indicated two factors: nightmare frequency and nightmare distress. The authors conclude it is a reliable measure of nightmare severity. |
Abstract
Study
Objectives: This study aimed to examine psychometric properties of the Disturbing Dream and Nightmare Severity Index (DDNSI) in individuals aged between 18 and 39.
Methods: All participants (n = 674) were asked to complete the DDNSI, including the modified Nightmare Effects Survey. Additionally, 109 participants were tested for test-retest reliability after 3 months. Among our sample, 229 (33.9%) reported having at least 1 nightmare per month.
Results: Internal consistency was evaluated for the total sample (Cronbach's α = .920) and separately for individuals reporting more than once per month (Cronbach's α = .755). Test-retest reliability after 3 months was .705. Convergent validity of the DDNSI with Nightmare Effects Survey was also satisfactory (r = .638, P < .001). Finally, exploratory factor analysis was conducted to explore the construct of the DDNSI, and results indicated that it consisted of 2 factors, nightmare frequency and nightmare distress [χ²(df) = 2.241(1) ∆χ² (∆df) = 155.575(4), Tucker-Lewis incremental fit index = .980, root mean square error of approximation (90% confidence interval) = .074 (0, .208), standardized root-mean-square residual = .011].
Conclusions: The DDNSI is a reliable measure of nightmare severity that can be used in various settings.
Citations in the library
Cited by 8
- The phenomenology of nightmares in post-traumatic stress disorder and complex post-traumatic stress disorder European Journal of Trauma & Dissociation June 30, 2023
- The mediation effects of nightmares and depression between insomnia and suicidal ideation in young adults Scientific Reports April 26, 2024
- The association between dream activity and alexithymia during pregnancy: A cross-sectional study in a sample of pregnant women. Journal of Sleep Research August 1, 2025
- Development and Validation of a Semi-Structured Clinical Interview for Nightmare Disorder Journal of Sleep Medicine April 29, 2021
- Nightmare Disorder. Sleep Medicine Clinics March 1, 2024
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Cites 17
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- Prevalence and Correlates of Frequent Nightmares: A Community-Based 2-Phase Study Sleep June 1, 2010
- Prevalence of Nightmare Disorder in Psychiatric Outpatients Psychotherapy and Psychosomatics 2013
- Nightmares affect the experience of sleep quality but not sleep architecture: an ambulatory polysomnographic study Borderline Personality Disorder and Emotion Dysregulation February 12, 2015
and 12 more in the library