https://orcid.org/0000-0002-6544-795X
ABSTRACT
Objectives
Previous studies showed that nightmares are prevalent and are associated with negative health outcomes. However, no empirical data is available demonstrating the extent to which nightmare disorder persists over time. Current literature provides a limited understanding of the trajectory and wider mental health outcomes of nightmare disorder. This longitudinal study examined the persistence and mental health outcomes of nightmare disorder.
Methods
A total of 230 Hong Kong Chinese adults completed standardized assessments twice with an interval of about 6 months.
Results
Over half (66.7%) of the participants with probable nightmare disorder at baseline remained to meet the DSM-5 criteria for the disorder at follow-up. Participants with probable nightmare disorder at baseline were significantly more likely to screen positive for PTSD (82.1% vs 18.3%) (p < .001) (p < .001), and they reported higher rates of mental health service usage at both timepoints (p = .001 to .003). Baseline nightmare disorder severity was negatively associated with subsequent self-rated mental health (β = -.151, p = .010) and self-esteem (β = -.141, p = .009) and it also predicted subsequent PTSD symptoms (β = .122, p = .012).
Conclusions
This study provides first empirical data showing that nightmare disorder could be persistent over time. Nightmare disorder symptoms are associated not only with PTSD symptoms but also with a broader range of mental health issues. This study points to the public health importance of identifying and managing nightmare disorder symptoms in the community. Additionally, the presence of nightmare disorder symptoms may be a helpful indicator for identifying post-traumatic stress.
Nightmare disorder is an official mental health condition in DSM-5 characterized by recurring, vivid, and distressing dreams that cause significant distress or impairment (American Psychiatric Association, Citation2013). According to DSM-5, the prevalence of monthly nightmares is 6% among adults, and the prevalence of frequent nightmares is about 1% to 2% (American Psychiatric Association, Citation2013). The prevalence of weekly nightmares was reported to be 1.31% in a representative German sample (Schredl, Citation2010). Although nightmare disorder could be a considerably disabling condition, most existing studies focused on nightmare episodes (i.e. frequency) rather than nightmare disorder; the available data regarding the prevalence and clinical course of nightmare disorder is very limited (Estevez, Citation2017). A small number of studies, however, showed that nightmare disorder could be prevalent. For example, Estevez (Citation2017) found that 4.9% of surveyed college students met the DSM-5 criteria for nightmare disorder. A national epidemiological study also reported a lifetime prevalence of 8.9% for nightmare disorder in Taiwan (Chen et al., Citation2020). In another sample of Chinese university students, Wang et al. (Citation2021) reported that 4.69% of participants had a nightmare disorder.
Nightmares are not only prevalent but are also associated with considerable physical and mental health outcomes. For instance, nightmares might increase the risk of developing cardiovascular diseases such as high blood pressure and heart problems (A. A. Campbell et al., Citation2023). Nightmares have also been found to be associated with depression (Hedström et al., Citation2021), anxiety (Wong et al., Citation2023), and psychotic symptoms, such as hallucinations (Kammerer et al., Citation2021).
Despite the potential clinical and public health significance of nightmare disorder, there are some significant research gaps in the literature. First, although it has been said that nightmare disorder could persist for decades (Stefani & Högl, Citation2021), to our knowledge, very few research demonstrates the extent to which the disorder persists over time. For example, Schultz et al. (Citation2021) suggested that the mean nightmare duration of 300 students at 10–12 years old is 2.48 years, with an average weekly frequency of 4.20 nights. Understanding the persistence of nightmare disorder over time is important because it can help researchers and health care service providers better understand the trajectory of the disorder, and it can also help raise awareness about the disorder and its impacts. Second, there are insufficient data regarding the long-term mental health consequences associated with nightmare disorder. Even for nightmare frequency rather than nightmare disorder, there are only a few longitudinal studies on its mental health outcomes (for a systematic review, see Sheaves et al., Citation2023). Furthermore, most existing studies investigated nightmare frequency rather than nightmare disorder or its severity, and most studies relied on single-item measures of nightmares, and therefore could hardly capture the full aspect of nightmare disorder (Dietch et al., Citation2021). Taking together, current literature provides a limited understanding of the trajectory of and mental health outcomes associated with nightmare disorder.
Against this background, the present study made the first attempt to examine the persistence of DSM-5 nightmare disorder. We also further investigated the long-term mental health outcomes associated with nightmare disorder severity. In addition to self-rated mental health, which is an important indicator of mental well-being commonly measured in epidemiological studies (Ahmad et al., Citation2014), we also included post-traumatic stress disorder (PTSD) symptoms and self-esteem as the dependent variables that were hypothesized to be associated with nightmare disorder severity. Nightmares are often associated with PTSD (R. L. Campbell & Germain, Citation2016; Cranston et al., Citation2017; George et al., Citation2016). From a trauma psychology perspective, nightmares – in some cases – may also be conceptualized as memories that are dissociated or unintegrated and intrude into the conscious mind during sleep (Nijenhuis & Van der Hart, Citation2011). Therefore, we hypothesized that nightmare disorder severity would predict subsequent PTSD symptoms. In addition, self-esteem often plays a crucial role in many important real-life outcomes (Orth et al., Citation2012); low self-esteem is also a helpful indicator of psychopathology (Isomaa et al., Citation2013) and is associated with mental health symptoms such as depression and anxiety (Sowislo & Orth, Citation2013). More importantly, repeated nightmares can be particularly distressing and can disrupt sleep, leading to fatigue and daytime impairment. Previous studies have indicated that sleep problems are related to poor psychosocial functioning, including poor self-esteem (e.g., Lemola et al., Citation2013; Roberts et al., Citation2002). Poor sleep not only predicted depressive symptoms but also poor self-esteem over time (Yip, Citation2015). Nevertheless, to our knowledge, no studies had explored the longitudinal effects of nightmare disorder severity on self-esteem. Therefore, we also hypothesized that baseline nightmare disorder severity would be negatively associated with subsequent self-esteem. Finally, because of the potential mental health impacts of nightmare disorder, we also hypothesized that participants with nightmare disorder would be more likely to receive mental health services than those without nightmare disorder. Taken together, this study contributes to the literature by highlighting the persistence of DSM-5 nightmare disorder and its association with various mental health outcomes, including but not limited to post-traumatic symptoms.
Methods
Participants
This study analyzed data from a psychological health survey study, which obtained ethical approval at the Chinese University of Hong Kong. Participants were recruited on social networking sites from November to December 2022. The inclusion criteria were as follows: potential participants should 1) be aged between 18 and 64, 2) provide informed consent and participate voluntarily, 3) be a resident of Hong Kong and currently living in Hong Kong, 4) be able to read and write Chinese, and 5) have Internet access. Participants with a diagnosis of a learning or reading disorder, dementia, or cognitive impairments were excluded in this study. Eligible participants were invited to complete an online survey consisting of a battery ofstandardized self-report measures at baseline and at 6-month follow-up. Part of the data unrelated to nightmare disorder has been reported elsewhere (Lam et al., Citation2023). No incentives were provide for participants.
At baseline, a total of 412 participants met all inclusion criteria and provided a valid response. However, 18 of them did not provide a valid e-mail address for follow-up. After approximately 6 months (M = 167.28 days; SD = 10.50), 230 participants provided a valid response to the follow-up survey (retention rate = 230/394 = 58.38%). They were included for analysis in this prospective study.
Participants aged from 18 to 64 (M = 39.73; SD = 12.75). Most participants were female (83.0%) and unmarried (62.6%) and had an undergraduate degree (59.6%). A subgroup of participants (29.1%) reported seeing a psychiatrist in the past 12 months.
Chi-square tests revealed no statistically significant differences in these demographic variables between participants who completed the follow-up survey (n = 230) and those who did not (n = 182). Additionally, on the Nightmare Disorder Index (NDI), the two groups did not differ in the nightmare disorder severity score (p = .720) or the rate of a probable DSM-5 diagnosis of nightmare disorder (p = .223) at baseline. Nevertheless, independent sample t test showed that participants who completed the follow-up survey were slightly older than those who did not (M = 39.73; SD = 13.1 vs M = 37.11; SD = 13.10), t = 2.047, p = .041.
Measures
Participants completed questions about demographic backgrounds in addition to the following self-report measures at both baseline and follow-up.
The Nightmare Disorder Index (NDI)
The NDI is a novel 5-item self-report measure of DSM-5 nightmare disorder with good internal consistency (α = .80) and satisfactory construct validity (r = .32 to .45) (Dietch et al., Citation2021). The NDI can be summed to obtain a total score (possible range: 0 to 20) – higher scores indicate greater nightmare severity. Additionally, the NDI can be used to assess if one meets the DSM-5 criteria for nightmare disorder (see Dietch et al., Citation2021), thus making a probable nightmare disorder diagnosis. With the permission from the original developer, we translated the NDI into Chinese using the collaborative translation approach (Douglas & Craig, Citation2007; Khosravani & Dastjerdi, Citation2013). The translation team consisted of researchers and mental health practitioners, including social workers, psychologists, and nurses. At baseline (N = 412), the Chinese version of the NDI (total score) had good internal consistency (α = .863) and was highly correlated (r = .803, p < .001) with an independent item on nightmare experience “Have you suffered from nightmares in the past month?” (0 = Never; 10 = Always). At follow-up (N = 230), it also had good internal consistency (α = .881) and was highly correlated with the independent nightmare item too (r = .849, p < .001). Therefore, the Chinese version of the NDI had good reliability and convergent validity in the present study, which was comparable to the results of Zhuang et al. (Citation2023).
The single-item measure of self-rated mental health (SRMH)
The single-item measure of SMRH asked, “How would you rate your overall mental health?” (1 = poor, 5 = excellent) (Ahmad et al., Citation2014). Just like the single-item measure of self-rated health (SRH), single-item measures of SMRH have been widely used in epidemiologic studies since 1970s (Ahmad et al., Citation2014), and it also had good convergent validity (r = −.48 with depressive symptoms, r = −.43 with functional disability) in the Chinese context (Jang et al., Citation2012). Additionally, the single-item measure of SRMH had moderate to good test–retest reliability (ICC = .749, 95% CI: .652–.821, p < .001) after 1 week and a strong correlation with depressive symptoms (r = .665, p < .001) in another sample of young Chinese adults (N = 205) (Fung, Lam, et al., Citation2024).
The single-item measure of self-esteem (SISE)
The SISE, which asked, “How satisfied are you with yourself?” (1 = very dissatisfied, 9 = very satisfied), is a valid single-item measure of self-esteem (Sawicki–Luiza & Atroszko, Citation2017). It has been found that both multi-item and single-item measures of self-esteem have very consistent relationships with other psychological and health variables (Robins et al., Citation2001). The Chinese version of the SISE had good test–retest reliability (ICC = .815, p < .001) and construct validity (r = −.596 to −.602 with depressive symptoms, p < .001) (Fung, Chan, et al., Citation2022).
The Post-traumatic Stress Disorder Checklist for DSM-5 (PCL-5)
The PCL-5 is a 20-item self-report measure of post-traumatic stress disorder (PTSD) symptoms with excellent internal consistency (α = .94), good test–retest reliability (r = .82), good convergent validity (r = .74 to .85), and excellent diagnostic validity (sensitivity = 94.1%, specificity = 93.9%) (Blevins et al., Citation2015; Geier et al., Citation2019). The Chinese version of the PCL-5 was also found to have excellent internal consistency (α = .951) and acceptable diagnostic validity (sensitivity = 70.6%, specificity = 72.7% when a cutoff of ≥49 was used) in a sample of psychiatric outpatients (Fung et al., Citation2019). The PCL-5 has one item specifically related to trauma-related disturbing dreams (item 2). This item was removed when we conducted the multiple regression analysis to examine the relationship between baseline nightmare disorder severity and subsequent PTSD symptoms.
In the surveys, we also asked about the use of mental health services. At baseline, we asked whether they had seen a psychiatrist in the past 12 months. At follow-up, we also asked about the recent use of medication and psychological treatments.
Data analysis
SPSS 22.0 was used for statistical analyses. We first conducted descriptive analysis and reported the frequency of probable nightmare disorder at each timepoint. We then examined whether baseline nightmare disorder severity (the NDI total score) would be associated with subsequent mental health outcomes (i.e., SRMH, SISE, and PCL-5 scores) by conducting hierarchical multiple regression analyses. Baseline scores of the dependent variable were controlled for. Since this study involved multiple testing (three different sets of regression analyses), the Bonferroni correction was applied, and the significance level was set to 0.0167. Finally, we conducted chi-square analyses to examine whether participants with probable nightmare disorder at baseline would be more likely to report receiving mental health services at both timepoints.
Results
At baseline, 39 participants (17.0%) met the criteria for DSM-5 nightmare disorder. Among them, 66.7% remained to meet the DSM-5 criteria for nightmare disorder at follow-up. For those without DSM-5 nightmare disorder at baseline (N = 191), only 7.3% met the DSM-5 criteria for nightmare disorder at follow-up. Additionally, participants with probable nightmare disorder at baseline were significantly more likely to screen positive for PTSD (i.e., PCL-5 ≥ 49) at both baseline (82.1% vs 18.3%) (p < .001) and follow-up (69.2% vs 17.8%) (p < .001) (see ).
Table 1. Hierarchical multiple regression predicting outcomes at follow-up (N = 230).
Hierarchical multiple regression analyses indicated that baseline nightmare disorder severity (NDI score) was negatively associated with subsequent self-rated mental health (β = −.151, p = .010) and self-esteem (β = −.141, p = .009) and it also predicted subsequent PTSD symptoms (β = .122, p = .012) (see ). The relationship remained statistically significant applying the Bonferroni correction and setting the significance level to 0.0167. Notably, in the regression analysis, the disturbing dream item (Item 2) of the PCL-5 was excluded to focus on the relationship between baseline nightmare disorder severity and subsequent PTSD symptoms without confounding the influences of PTSD-specific nightmares.
We repeated the analyses again and further controlled for effects of the use of medications within the past 3 months. To do so, in addition to the baseline scores, we also entered the use of medications into the Step 1 in each hierarchical multiple regression analysis. This time, baseline nightmare disorder severity (NDI score) was significantly associated with subsequent self-rated mental health (β = −.132, p = .027) and PTSD symptoms (β = .095, p = .049), but not with self-esteem (β = −.103, p = .058).
Additionally, chi-square tests showed that participants with probable nightmare disorder at baseline were more likely to report seeing a psychiatrist at baseline (p = .001), as well as using medication (p = .003) and receiving psychological treatments (p = .001) for mental health problems at follow-up. The findings are reported in .
Table 2. Association of nightmare disorder with probable post-traumatic stress disorder (PTSD) and mental health service usage.
Discussion
This study provides the first empirical data showing that nightmare disorder could be persistent over time. Additionally, baseline nightmare disorder severity predicted subsequent PTSD symptoms and was negatively associated with self-rated mental health and self-esteem at follow-up. Even after further controlling for the effects of the use of medications for mental health problems in the past 3 months (reported at follow-up), baseline nightmare disorder severity still predicted self-rated mental health (β = −.132, p = .027) and PTSD symptoms (β = .095, p = .049) at follow up. The findings contribute to the limited body of knowledge on the persistence and overall mental health correlates of nightmare disorder and point to the public health importance of preventing and addressing nightmare in the community.
First of all, our study replicated previous findings which showed that nightmare is closely related to PTSD symptoms (Barlow & Cromer, Citation2006; Sheaves et al., Citation2023). It has been clinically observed that people with complex trauma and dissociation usually suffer from nightmares, which might implicate their dissociated memories or unintegrated parts of self (Dell, Citation2006; Fung, Citation2016). In the present study, we also found that nightmare disorder severity significantly predicted subsequent PTSD symptoms (even not including the PCL-5 disturbing dream item). More importantly, most participants with probable DSM-5 nightmare disorder screened positive for DSM-5 PTSD on the PCL-5 at both timepoints (69.2% to 82.1%). It supports the idea that nightmares may be an indicator of unprocessed trauma because probable PTSD was fairly common among most participants suffering from nightmares. Given its close relationship with post-traumatic stress, nightmares should receive more attention from health service providers in primacy care settings, and clients reporting nightmares should be screened for PTSD or other trauma-related mental health problems (e.g., dissociative disorders). Since trauma-related disorders are typically unrecognized in the community (Cusack et al., Citation2006; Wu et al., Citation2022), nightmare disorder symptoms may serve as a useful diagnostic window for clinicians to recognize trauma disorders in primary care settings (Chien & Fung, Citation2022).
Our findings indicate that nightmare disorder symptoms are associated not only with PTSD symptoms but also with a broader range of mental health issues, including lower levels of self-esteem as well as higher rates of mental health service usage. This is in fact the first study showing that nightmare disorder symptoms negatively predict how satisfied one is with him/herself, implying that nightmares may affect the whole person’s mental well-being. Our findings are consistent with previous studies which also showed that poor sleep is associated with poor self-esteem (e.g., Yip, Citation2015). More importantly, we found that probable DSM-5 nightmare disorder was persistent even after approximately 6 months − 66.7% of participants with baseline nightmare disorder remained to meet the DSM-5 criteria for nightmare disorder at follow-up. Therefore, this study offers compelling evidence that underscores the critical importance of identifying and managing nightmare disorder symptoms early on in the community. The study’s findings highlight the urgent need for timely intervention and treatment to prevent the negative impact of these symptoms on individuals’ mental health and overall quality of life. It is important to note that interventions for nightmares exist and are effective (for a meta-analysis, see Hansen et al., Citation2013). Therefore, if we can identify nightmare disorder symptoms early, we have the chance to change its trajectory and mitigate its significant mental health impacts on individuals and their families.
This study has the strengths of using a longitudinal design, capturing a wider range of nightmare disorder symptoms (i.e., frequency, intensity, duration, and distress and impairment related to nightmares), and using reliable and valid mental health measures. However, this study also has several limitations. First, our sample was not representative of the general population because self-selection bias may occur in online survey studies. Most participants were female in our sample. One possible reason is that females may be more willing to participate in health-related surveys than males (Glass et al., Citation2015). Females may also be more likely than males to use social media platforms (Noguti et al., Citation2019). It is, however, important to note that a few previous studies showed that women may have a higher tendency of having nightmares than men (Sandman et al., Citation2013; Schredl & Reinhard, Citation2011; Stefani & Högl, Citation2021). Therefore, although the limited generalizability of our findings should be clearly acknowledged, our findings may still contribute to the literature as nightmares may be particularly common among females. Second, we had a relatively high attrition rate, which would further limit the representativeness of our sample. Althoug hour analyses showed that participants who completed the survey at one or both time points were largely comparable, it is a notable confound of the study. Third, we did not conduct independent structured interviews to diagnose nightmare disorder and PTSD; we only relied on self-report measures, although these are commonly used and well-validated screening tools. Fourth, although some participants reported that they received medication treatments, we did not know what medications they were using and whether some specific medications would have impacts on sleep conditions. Finally, as cultures could affect how we manage stress and regulate our emotions (Nagulendran & Jobson, Citation2020), there may be cultural differences in the mental health effects of nightmare disorder. For example, prior studies showed that Chinese might endorse more somatic symptoms under emotional distress (Ryder et al., Citation2008). Therefore, future studies should further investigate the mental health impacts of nightmare disorder across sociocultural contexts, using more diverse, representative, clinical and nonclinical samples, and employing multiple assessment methods.
Concluding remarks
This is the first empirical study showing that nightmare disorder persists over time. This belief is commonly held, but it has not been tested in previous studies. In addition, we found that most participants with probable nightmare disorder (82.1%) also had probable PTSD. Nightmare disorder symptoms are not only associated with PTSD symptoms but also lower levels of self-rated mental health and self-esteem and higher rates of mental health service usage. This study provides strong evidence for the importance of early identification and timely management of nightmare disorder symptoms in the community. Additionally, our findings suggest that the presence of nightmare disorder symptoms can be a helpful indicator for identifying post-traumatic stress.
Acknowledgments
The last author received The RGC Postdoctoral Fellowship Scheme 2022/2023 from the Research Grants Council (RGC), Hong Kong.
Disclosure statement
No potential conflict of interest was reported by the author(s).
Data availability statement
Data that support the findings of this study are available from the corresponding authors upon reasonable request.
Additional information
Funding
References
- Ahmad, F., Jhajj, A. K., Stewart, D. E., Burghardt, M., & Bierman, A. S. (2014). Single item measures of self-rated mental health: A scoping review. BMC Health Services Research, 14(1), 1–11. https://doi.org/10.1186/1472-6963-14-398
- American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). American Psychiatric Publishing, Inc. https://doi.org/10.1176/appi.books.9780890425596
- Barlow, M. R., & Cromer, L. D. (2006). Trauma-relevant characteristics in a university human subjects pool population: Gender, major, betrayal, and latency of participation. Journal of Trauma & Dissociation, 7(2), 59–75. https://doi.org/10.1300/J229v07n02_05
- Blevins, C. A., Weathers, F. W., Davis, M. T., Witte, T. K., & Domino, J. L. (2015). The posttraumatic stress disorder checklist for DSM‐5 (PCL‐5): Development and initial psychometric evaluation. Journal of Traumatic Stress, 28(6), 489–498. https://doi.org/10.1002/jts.22059
- Campbell, R. L., & Germain, A. (2016). Nightmares and posttraumatic stress disorder (PTSD). Current Sleep Medicine Reports, 2(2), 74–80. https://doi.org/10.1007/s40675-016-0037-0
- Campbell, A. A., Taylor, K. A., Augustine, A. V., Sherwood, A., Wu, J. Q., Beckham, J. C., Hoerle, J. M., MIRECC, V. M.-A., & Ulmer, C. S. (2023). Nightmares: An independent risk factor for cardiovascular disease? Sleep, 46(6). https://doi.org/10.1093/sleep/zsad089
- Chen, Y.-L., Chen, W. J., Lin, K.-C., Shen, L.-J., & Gau, S. S.-F. (2020). Prevalence of DSM-5 mental disorders in a nationally representative sample of children in Taiwan: Methodology and main findings. Epidemiology and Psychiatric Sciences, 29, e15. https://doi.org/10.1017/S2045796018000793
- Chien, W. T., & Fung, H. W. (2022). Commentary: The assessment of dissociative pathology in culturally and clinically diverse contexts. Alpha Psychiatry, 23(3), 104–105. https://doi.org/10.5152/alphapsychiatry.2022.0006
- Cranston, C. C., Miller, K. E., Davis, J. L., & Rhudy, J. L. (2017). Preliminary validation of a brief measure of the frequency and severity of nightmares: The trauma-related nightmare survey. Journal of Trauma & Dissociation, 18(1), 88–99. https://doi.org/10.1080/15299732.2016.1191578
- Cusack, K. J., Grubaugh, A. L., Knapp, R. G., & Frueh, B. C. (2006). Unrecognized trauma and PTSD among public mental health consumers with chronic and severe mental illness. Community Mental Health Journal, 42(5), 487–500. https://doi.org/10.1007/s10597-006-9049-4
- Dell, P. F. (2006). The multidimensional inventory of dissociation (MID): A comprehensive measure of pathological dissociation. Journal of Trauma & Dissociation, 7(2), 77–106. https://doi.org/10.1300/J229v07n02_06
- Dietch, J. R., Taylor, D. J., Pruiksma, K., Wardle-Pinkston, S., Slavish, D. C., Messman, B., Estevez, R., Ruggero, C. J., & Kelly, K. (2021). The nightmare disorder index: Development and initial validation in a sample of nurses. Sleep, 44(5), zsaa254. https://doi.org/10.1093/sleep/zsaa254
- Douglas, S. P., & Craig, C. S. (2007). Collaborative and iterative translation: An alternative approach to back translation. Journal of International Marketing, 15(1), 30–43. https://doi.org/10.1509/jimk.15.1.030
- Estevez, R. (2017). Nightmare Disorder Prevalence as Defined by the DSM-5 in a College Sample. University of North Texas. https://digital.library.unt.edu/ark:/67531/metadc1011749/m2/1/high_res_d/ESTEVEZ-DISSERTATION-2017.pdf
- Fung, H. W. (2016). Trauma-related pathological dissociation in a case with cerebral palsy. Journal of Trauma & Dissociation, 17(3), 286–293. https://doi.org/10.1080/15299732.2015.1080780
- Fung, H. W., Chan, C., Chien, W. T., Chong, Y. Y., & Ross, C. A. (2022). The acceptability and potential benefits of a web-based psychoeducation program for people with pathological dissociation: A pilot evaluation study. Journal of Trauma & Dissociation, 24(1), 95–110. https://doi.org/10.1080/15299732.2022.2119457
- Fung, H. W., Chan, C., Lee, C. Y., & Ross, C. A. (2019). Using the Post-traumatic Stress Disorder (PTSD) checklist for DSM-5 to screen for PTSD in the Chinese context: A pilot study in a psychiatric sample. Journal of Evidence-Based Social Work, 16(6), 643–651. https://doi.org/10.1080/26408066.2019.1676858
- Fung, H. W., Lam, S. K. K., Chien, W. T., Ling, H. W. H., Wu, Z. Y., Ross, C. A., & Chau, A. K. C.(2024, January). Reliability and mental health correlates of a single-item measure of Self-Rated mental health (SRMH) in the Chinese context. Healthcare, 12(1).
- Geier, T. J., Hunt, J. C., Nelson, L. D., Brasel, K. J., & deRoon‐Cassini, T. A. (2019). Detecting PTSD in a traumatically injured population: The diagnostic utility of the PTSD checklist for DSM‐5. Depression and Anxiety, 36(2), 170–178. https://doi.org/10.1002/da.22873
- George, K. C., Kebejian, L., Ruth, L. J., Miller, C. W., & Himelhoch, S. (2016). Meta-analysis of the efficacy and safety of prazosin versus placebo for the treatment of nightmares and sleep disturbances in adults with posttraumatic stress disorder. Journal of Trauma & Dissociation, 17(4), 494–510. https://doi.org/10.1080/15299732.2016.1141150
- Glass, D. C., Kelsall, H. L., Slegers, C., Forbes, A. B., Loff, B., Zion, D., & Fritschi, L. (2015). A telephone survey of factors affecting willingness to participate in health research surveys. BMC Public Health, 15(1), 1017. https://doi.org/10.1186/s12889-015-2350-9
- Hansen, K., Höfling, V., Kröner-Borowik, T., Stangier, U., & Steil, R. (2013). Efficacy of psychological interventions aiming to reduce chronic nightmares: A meta-analysis. Clinical Psychology Review, 33(1), 146–155. https://doi.org/10.1016/j.cpr.2012.10.012
- Hedström, A. K., Bellocco, R., Hössjer, O., Ye, W., Trolle Lagerros, Y., & Åkerstedt, T. (2021). The relationship between nightmares, depression and suicide. Sleep Medicine, 77, 1–6. https://doi.org/10.1016/j.sleep.2020.11.018
- Isomaa, R., Väänänen, J.-M., Fröjd, S., Kaltiala-Heino, R., & Marttunen, M. (2013). How low is low? Low self-esteem as an indicator of internalizing psychopathology in adolescence. Health Education & Behavior, 40(4), 392–399. https://doi.org/10.1177/1090198112445481
- Jang, Y., Park, N. S., Kim, G., Kwag, K. H., Roh, S., & Chiriboga, D. A. (2012). The association between self-rated mental health and symptoms of depression in Korean American older adults. Aging & Mental Health, 16(4), 481–485. https://doi.org/10.1080/13607863.2011.628981
- Kammerer, M. K., Bub, K., & Lincoln, T. M. (2021). The relationship between nightmares and psychotic experiences in young adults. Sleep Medicine, 77, 315–322. https://doi.org/10.1016/j.sleep.2020.08.014
- Khosravani, Y., & Dastjerdi, H. V. (2013). Back translation vs. collaborative translation: A comparative study of Persian subtitles in English movies. Lebende Sprachen, 58(2), 366–378. https://doi.org/10.1515/les-2013-0021
- Lam, S. K. K., Ng, A. S. Y., Zhou, C. R., Hung, S. L., & Fung, H. W. (2023). Persistence and psychological predictors of ICD-11 complex PTSD: A six-month longitudinal study in Hong Kong. Journal of Loss and Trauma, 1–21. https://doi.org/10.1080/15325024.2023.2267433
- Lemola, S., Räikkönen, K., Gomez, V., & Allemand, M. (2013). Optimism and self-esteem are related to sleep. Results from a large community-based sample. International Journal of Behavioral Medicine, 20(4), 567–571. https://doi.org/10.1007/s12529-012-9272-z
- Nagulendran, A., & Jobson, L. (2020). Exploring cultural differences in the use of emotion regulation strategies in posttraumatic stress disorder. European Journal of Psychotraumatology, 11(1), 1729033. https://doi.org/10.1080/20008198.2020.1729033
- Nijenhuis, E. R., & Van der Hart, O. (2011). Dissociation in trauma: A new definition and comparison with previous formulations. Journal of Trauma & Dissociation, 12(4), 416–445. https://doi.org/10.1080/15299732.2011.570592
- Noguti, V., Singh, S., & Waller, D. S. (2019). Gender differences in motivations to use social networking sites (Gender economics: Breakthroughs in research and practice. IGI Global. https://doi.org/10.4018/978-1-5225-7510-8.ch033
- Orth, U., Robins, R. W., & Widaman, K. F. (2012). Life-span development of self-esteem and its effects on important life outcomes. Journal of Personality and Social Psychology, 102(6), 1271. https://doi.org/10.1037/a0025558
- Roberts, R. E., Ramsay Roberts, C., & Ger Chen, I. (2002). Impact of insomnia on future functioning of adolescents. Journal of Psychosomatic Research, 53(1), 561–569. https://doi.org/10.1016/S0022-3999(02)00446-4
- Robins, R. W., Hendin, H. M., & Trzesniewski, K. H. (2001). Measuring global self-esteem: Construct validation of a single-item measure and the Rosenberg self-esteem scale. Personality and Social Psychology Bulletin, 27(2), 151–161. https://doi.org/10.1177/0146167201272002
- Ryder, A. G., Yang, J., Zhu, X., Yao, S., Yi, J., Heine, S. J., & Bagby, R. M. (2008). The cultural shaping of depression: Somatic symptoms in China, psychological symptoms in North America? Journal of Abnormal Psychology, 117(2), 300. https://doi.org/10.1037/0021-843X.117.2.300
- Sandman, N., Valli, K., Kronholm, E., Ollila, H. M., Revonsuo, A., Laatikainen, T., & Paunio, T. (2013). Nightmares: Prevalence among the Finnish general adult population and war veterans during 1972-2007. Sleep, 36(7), 1041–1050. https://doi.org/10.5665/sleep.2806
- Sawicki–Luiza, P. A. A. A., & Atroszko, S. B. (2017). Validity and reliability of single-item self-report measure of global self-esteem. CER Comparative European Research
- Schredl, M. (2010). Nightmare frequency and nightmare topics in a representative German sample. European Archives of Psychiatry and Clinical Neuroscience, 260(8), 565–570. https://doi.org/10.1007/s00406-010-0112-3
- Schredl, M., & Reinhard, I. (2011). Gender differences in nightmare frequency: A meta-analysis. Sleep Medicine Reviews, 15(2), 115–121. https://doi.org/10.1016/j.smrv.2010.06.002
- Schultz, J.-H., Forsberg, J. T., Harb, G., & Alisic, E. (2021). Prevalence and characteristics of posttraumatic nightmares in war-and conflict-affected students. Nature and Science of Sleep, Volume 13, 423–433. https://doi.org/10.2147/NSS.S282967
- Sheaves, B., Rek, S., & Freeman, D. (2023). Nightmares and psychiatric symptoms: A systematic review of longitudinal, experimental, and clinical trial studies. Clinical Psychology Review, 100, 102241. https://doi.org/10.1016/j.cpr.2022.102241
- Sowislo, J. F., & Orth, U. (2013). Does low self-esteem predict depression and anxiety? A meta-analysis of longitudinal studies. Psychological Bulletin, 139(1), 213–240. https://doi.org/10.1037/a0028931
- Stefani, A., & Högl, B. (2021). Nightmare disorder and isolated sleep paralysis. Neurotherapeutics: The Journal of the American Society for Experimental NeuroTherapeutics, 18(1), 100–106. https://doi.org/10.1007/s13311-020-00966-8
- Wang, C., Xu, J., Wang, M., Shao, X., & Wang, W. (2021). Prevalence and detailed experience of nightmare and nightmare disorder in Chinese university students. SAGE Open, 11(2), 21582440211014193. https://doi.org/10.1177/21582440211014193
- Wong, S. M., Hui, C. L., Cheung, V. K., Suen, Y. N., Chan, S. K., Lee, E. H., Chan, K. T., Wong, M. T., & Chen, E. Y. (2023). Prevalence of frequent nightmares and their prospective associations with 1-year psychiatric symptoms and disorders and functioning in young adults: A large-scale epidemiological study in Hong Kong. Sleep, 46(4), zsac296. https://doi.org/10.1093/sleep/zsac296
- Wu, Z. Y., Fung, H. W., Chien, W. T., Ross, C. A., & Lam, S. K. K. (2022). Trauma and dissociation among inpatients diagnosed with schizophrenia spectrum disorders in Taiwan. European Journal of Psychotraumatology, 13(2), 2105576. https://doi.org/10.1080/20008066.2022.2105576
- Yip, T. (2015). The effects of ethnic/racial discrimination and sleep quality on depressive symptoms and self-esteem trajectories among diverse adolescents. Journal of Youth and Adolescence, 44(2), 419–430. https://doi.org/10.1007/s10964-014-0123-x
- Zhuang, Y. Y., Wang, L. L., Song, T. H., Dietch, J. R., Wang, T. T., Qi, M., Liu, J. M., Zhou, S. J., & Chen, J. X. (2023). Reliability and validity of the Chinese version of the nightmare disorder index in adolescents. Stress & Health, 39(4), 894–901. https://doi.org/10.1002/smi.3228