Predictors of dropout in university students participating in an 8-week e-mail-based cognitive-behavioral therapy for insomnia intervention.

PURPOSE: We conducted an exploratory study to identify risk factors of dropout in an 8-week e-mail-based cognitive-behavioral therapy for insomnia (REFRESH) to improve sleep among university students with insomnia symptoms. METHODS: University and graduate students in Hong Kong and Korea who scored higher than 10 on the Insomnia Severity Index participated in REFRESH. RESULTS: Of 158 participants from Hong Kong (n = 43) and Korea (n = 115), 90 (57%) did not complete all 7 sessions, while 52 of 90 (57.8%) dropped out prior to the fourth session. ROC analysis was conducted on the entire sample of 158 participants with intervention completion vs. dropout (non-completion) as the outcome variable. Predictors of dropout were wake time after sleep onset (WASO) < 7.1 min on the weekly sleep diary and expectations for sleep (a subscale of dysfunctional beliefs and attitudes about sleep; DBAS) < 18 at baseline. CONCLUSIONS: These findings indicate that shorter WASO and less expectations for sleep at baseline were associated with risk of dropout from e-mail delivered self-help CBT-I-based intervention. Our results highlight the importance of identifying and tailoring treatment formats to students based on their presenting sleep characteristics.

Development and validation of the Japanese version of the Hyperarousal Scale.

BACKGROUND: The objectives of this study were to develop a Japanese version of the Hyperarousal Scale (HAS-J) and investigate its factor structure, reliability, and validity, as well as to calculate a cutoff score for the HAS-J and assess different levels of hyperarousal in insomnia patients and community dwellers. METHODS: We recruited 224 outpatients receiving insomnia treatment (56.3% women; mean age 51.7 ± 15.6 years) and 303 community dwellers aged 20 years or older (57.8% women; mean age 43.9 ± 15.2 years). Exploratory and confirmatory factor analysis was performed to examine the factor structure of the HAS-J. Cronbach's α and McDonald's ω were then used to test internal consistency. To examine the scale's validity, we determined correlations between the HAS-J and other indexes and compared HAS-J scores between insomnia patients and community dwellers. We also compared HAS-J scores between two community-dweller groups (normal and poor sleepers) and two insomnia patient groups (with and without alleviation after treatment). RESULTS: Following exploratory and confirmatory factor analysis, a 20-item measure emerged comprising three factors: "Introspectiveness and Reactivity," "Neuroticism," and "Insomnia." Confirmatory factor analysis showed a generally good fit for the model of the three-factor structure suggested by the exploratory factor analysis loadings (χ2 (163) = 327.423, (p <  0.001), CFI = 0.914, GFI = 0.872, AGFI = 0.835, RMSEA = 0.067). In insomnia patients, internal consistency indicated sufficient reliability of the HAS-J. Correlation analysis showed weak to moderate positive correlations of the HAS-J score with other indexes, indicating concurrent validity of the HAS-J. All HAS-J subscale scores were significantly higher in insomnia patients than in community dwellers. Additionally, the total score in patients with alleviation of insomnia was comparable to that in poor sleepers and significantly higher than that in normal sleepers. CONCLUSIONS: This study demonstrated the reliability and validity of the HAS-J, indicating that it is useful as a clinical scale of hyperarousal. The high level of hyperarousal in insomnia patients who were assessed to be in remission by the Insomnia Severity Index suggests a risk of insomnia recurrence in these patients.

Development and Validity of the Japanese Version of the Pre-Sleep Arousal Scale.

Hyperarousal, defined as increased levels of cortical activity and cognitive-emotional reactivity induced by stress, is suggested to be a key factor in insomnia. In particularly, pre-sleep arousal constitutes one of the major features of insomnia. The Pre-Sleep Arousal Scale is the best-known measure used to evaluate pre-sleep arousal. However, a well-validated Japanese version of the scale (PSAS-J) has not yet been established. The aim of this research was to develop and validate such a scale. A cross-sectional questionnaire-based study was conducted via the internet. In total, 237 of 300 participants (mean age 43.28 ± 11.19 years) completely responded to the questionnaires as followed: the PSAS-J, the Insomnia Severity Index, Ford Insomnia Response to Stress Test, and Dysfunctional Beliefs and Attitudes about Sleep Scale. In addition, the participants were divided into two groups: insomniacs and normal sleepers. As a result, the PSAS-J had a two-factor structure similar to that of the original version, i.e., somatic and cognitive arousal subscales. The internal consistency (α = 0.85 to 0.90) and test-retest reliability (r = 0.67 to 0.78) were high. Correlations between the PSAS-J and the above-mentioned scales ranged from 0.35 to 0.53. Discriminant validity showed that the PSAS-J was distinct from the Ford Insomnia Response to Stress Test and Dysfunctional Beliefs and Attitudes about Sleep Scale. The PSAS-J scores were significantly higher in insomniacs than in normal sleepers. Our results suggest that the PSAS-J has high reliability and validity and that this scale is adequate for assessing pre-sleep arousal.

Efficacy and safety of bright light therapy for manic and depressive symptoms in patients with bipolar disorder: A systematic review and meta-analysis.

AIM: This systematic review and meta-analysis evaluated whether bright light therapy (BLT) is an effective and safe treatment for manic/depressive symptoms and a preventive measure for recurrent mood episodes in patients with bipolar disorder. METHODS: A literature search of major electronic databases was conducted in June 2019, including all published articles up to that date. Two researchers independently selected relevant publications, extracted data, and evaluated methodological quality according to the Cochrane criteria. RESULTS: Six randomized controlled trials (RCT) evaluated the efficacy of BLT for bipolar depression. A meta-analysis found no significant differences between BLT and placebo for the following outcomes: (i) rates of remission from depressive episodes (risk ratio [RR]: 1.81, 95% confidence interval [CI]: 0.43 to 7.64, P = 0.42); (ii) depressive symptom scores (standardized mean difference: -0.25, 95%CI: -0.74 to 0.23, P = 0.30); and (iii) rates of manic switching (RR: 1.00, 95%CI: 0.28 to 3.59, P = 0.26). The sensitivity analysis for studies with low overall indirectness did show a significant antidepressant effect for BLT (RR: 3.09, 95%CI: 1.62 to 5.90, P = 0.006). No RCT investigated the effect of BLT in preventing the recurrence of mood episodes in the euthymic state or in improving manic symptoms in the manic state. No severe adverse events were reported. CONCLUSION: While a meta-analysis was unable to demonstrate the efficacy of BLT for bipolar depression, a sensitivity analysis did show a significant effect. Further well-designed studies are needed to clarify the effectiveness of BLT, not only for the depressive state but also for other states, in the treatment of bipolar disorder.

Mental Health Problems among Undergraduates in Fukushima, Tokyo, and Kyoto after the March 11 Tohoku Earthquake.

On March 11, 2011, the Great East Japan Earthquake devastated the Tohoku region, which led to a tsunami and a nuclear disaster. While these three disasters caused tremendous physical damage, their psychological impact remains unclear. The present study evaluated traumatic responses, internalizing (i.e., anxiety and depression), and externalizing (i.e., anger) symptoms among Japanese young people in the immediate aftermath and 2.5 years later. A total of 435 undergraduates were recruited from universities in three differentially exposed regions: Fukushima, Tokyo, and Kyoto. They completed a set of questionnaires retrospectively (i.e., September to December 2013) to measure their traumatic responses, anxiety and depressive symptoms, functional impairment, and anger immediately after the disaster and 2.5 years later. Participants in Tokyo had the highest level of traumatic response and internalizing symptoms immediately after the earthquake, whereas those in Fukushima had significantly higher levels of trait anger, anger-in (holding one's anger in), and anger-out (expressing one's anger externally). In Kyoto, the levels of anxiety and depression after 2.5 years were significantly higher than they were immediately after the disasters. In conclusion, anger symptoms were high among young people who lived at or near the center of the disasters, while anxiety and depression were high among those who lived far away from the disasters. These findings suggest the importance of providing mental health services to young people who did not live near the disaster area as well as to those living in the directly affected area.

[Self-help intervention delivered via devices].

In general, cognitive behavioral therapy for insomnia(CBT-I) is conducted via face-to-face sessions. Recently, several devices have been developed to deliver self-help interventions to patients with insomnia via booklets, computers, telephone, e-mail, or television. In this article, I reviewed an efficacy of these self-help interventions for insomnia. Self-help interventions had a small to moderate positive effect compared with the control group, but was inferior to face-to-face therapy. However, I suggest that these self-help interventions may constitute a useful addition to existing intervention options especially when integrated in a stepped care approach, among individuals with insomnia who live in remote areas.

Cross-sectional analyses of factors associated with the presence and aggravation of chronic insomnia by symptom subtypes.

Aim: The aim of this study was to investigate the association of psychological and chronobiological factors with the presence and severity of chronic insomnia by symptom subtypes and their impacts on daytime dysfunctions. Methods: Participants of the present web-based epidemiological study were classified as follows: difficulty initiating sleep (DIS) (n = 91); difficulty maintaining sleep (DMS) (n = 13); early morning awakening (EMA) (n = 48); DIS + DMS (n = 67); DIS + EMA (n = 23); DMS + EMA (n = 24); triplet of DIS, DMS, and EMA symptoms (TRP) (n = 69); and normal sleepers (n = 4590). The Insomnia Severity Index (ISI), Hospital Anxiety and Depression Scale (HADS), Munich Chronotype Questionnaire (MCTQ), insomnia-related psychological measures (including the Ford Insomnia Response to Stress Test [FIRST] and the Dysfunctional Beliefs and Attitudes about Sleep Scale [DBAS]), and the cognitive and somatic domains of the Pre-Sleep Arousal Scale (PSAS) were evaluated. Results: The presence of DIS and DIS + DMS were significantly associated with an evening preference, and EMA and EMA + DMS with a morning preference, while TRP showed no significant association with either chronotype. The increase in DBAS scores was associated with higher ISI scores in all subtypes. Meanwhile, the associations of each psychological measure varied among insomnia subtypes, with the association of PSAS cognitive arousal to DIS and PSAS somatic arousal to both DMS + EMA and TRP. Pathological HADS score was associated with all subtypes. Conclusion: Chronotypes may be associated with the presence of some insomnia subtypes; however, only psychological factors were speculated to contribute to the aggravation of all subtypes. All insomnia subtypes possibly contribute to the formation of depression.

Psychometric properties of the Japanese version of the Insomnia Catastrophizing Scale and relationship of insomnia severity with catastrophic thoughts, safety behaviors, and dysfunctional beliefs.

BACKGROUND: This study aimed to clarify the reliability and validity of the Japanese version of the Insomnia Catastrophizing Scale (ICS) and to examine the relationship between insomnia severity and insomnia-related cognitive factors. METHODS: A total of 786 participants were recruited via an online survey and classified into the insomnia group (n = 342) and healthy group (n = 444). The insomnia group comprised individuals who self-reported meeting the diagnostic criteria for chronic insomnia disorder in the third edition of the International Classification of Sleep Disorders. RESULTS: The ICS is used to independently assess nighttime (ICS-N) and daytime (ICS-D) catastrophic thoughts, and item response theory revealed that each ICS-N and ICS-D item can adequately assess catastrophic thoughts during the night and day, respectively. The internal consistency and test-retest reliability of the ICS-N and ICS-D were good. Further, the ICS-N and ICS-D had a significant positive correlation with insomnia severity, hyperarousal, sleep-related safety behaviors, dysfunctional beliefs about sleep, and anxiety symptoms. Multiple regression analyses with insomnia severity as the dependent variable in the insomnia group demonstrated that catastrophic thoughts were more strongly associated with insomnia severity than sleep-related safety behaviors and dysfunctional beliefs about sleep. The interaction between nighttime catastrophic thoughts and sleep-related safety behaviors increased insomnia severity. CONCLUSIONS: The Japanese versions of ICS-N and ICS-D were found to be superior in measuring insomnia-related catastrophic thoughts and to have high reliability and validity. Furthermore, these findings more clearly demonstrate that the catastrophic thoughts may be an important associated factor of insomnia.

A psychometric analysis of the Japanese version of the clinically useful depression outcome scale supplemented with questions for the DSM-5 anxious distress specifier (CUDOS-A).

AIM: The aim of the study was to identify the clinical significance of anxiety in those with depression, the Diagnostic and Statistical Manual of Mental Disorders 5th edition (DSM-5) defined criteria for an anxious distress specifier for major depressive disorder (MDD). The Clinically Useful Depression Outcome Scale (CUDOS) supplemented with questions for the DSM-5 anxious distress specifier (CUDOS-A) is a self-report instrument to assess the clinical significance of anxiety in addition to assess symptoms and the severity of depression. This study aimed to evaluate the psychometric properties of the Japanese version of the CUDOS-A. METHODS: An observational, prospective study was conducted with 131 MDD outpatients and 200 healthy controls. The Japanese version of the CUDOS-A, along with other measures, was administered to assess depressive symptoms, anxiety, social function, and biological rhythm. Reliability and validity analyses were performed, including internal consistency, test-retest reliability, convergent validity, and contrasted-groups validity. RESULTS: The Japanese version of the CUDOS-A demonstrated excellent internal consistency (Cronbach's alpha = 0.96) and test-retest reliability (ICC = 0.78). Significant positive correlations were found between the CUDOS-A and measures of depression, anxiety, social function, and biological rhythm (all, p < 0.001), supporting its convergent validity. The CUDOS-A effectively differentiated between patients with MDD and healthy controls (p < 0.001), indicating good contrasted-groups validity. CONCLUSIONS: The Japanese version of the CUDOS-A is a useful measure for research and for clinical practice, enabling the efficient assessment of anxious distress in individuals with depression.

Assessing the Quick Inventory of Depressive Symptomatology Self-Report scores to predict continuous employment in mood disorder patients.

Objective: Depression significantly impacts the job performance and attendance of workers, leading to increased absenteeism. Predicting occupational engagement for individuals with depression is of paramount importance. This study aims to determine the cut-off score which predicts continuous employment for patients with mood disorders using the Quick Inventory of Depressive Symptomatology, Self-Report (QIDS-SR). Methods: In a prospective observational trial conducted in Tokyo, 111 outpatients diagnosed with either major depressive disorder or bipolar depression were enrolled. Their employment statuses of these participants were tracked over a six-month period after their QIDS-SR scores were recorded. Based on their employment trajectories, participants were categorized into either continuous or non-continuous employment groups. Binary logistic regression was applied to examine the relationship between the QIDS-SR scores and employment outcomes, with adjustments for age, gender, and psychiatric diagnoses. Receiver operating characteristic curves were utilized to identify the optimal QIDS-SR cut-off values for predicting continuous employment. Findings: Binary logistic regression demonstrated that a lower score on the QIDS-SR was linked to an elevated likelihood of continuous employment (adjusted odds ratio 1.15, 95% CI: 1.06-1.26, p=0.001). The optimal cut-off point, determined by the Youden Index, was 10/11, showcasing a 63% sensitivity and 71% specificity. Conclusion: The results emphasize the potential of the QIDS-SR as a prognostic instrument for predicting employment outcomes among individuals with depressive disorders. These findings further underscore the importance of managing depressive symptoms to mild or lower intensities to ensure ongoing employment.

Treatment strategies for insomnia in Japanese primary care physicians' practice: A Web-based questionnaire survey.

BACKGROUND: It is unclear how primary care physicians manage insomnia after the introduction of novel hypnotics such as orexin receptor antagonists and melatonin receptor agonists. This Web-based questionnaire survey aimed to examine treatment strategies for insomnia in Japanese primary care practice. METHODS: One-hundred-and-seventeen primary care physicians were surveyed on the familiarity of each management option for insomnia on a binary response scale (0 = "unfamiliar"; 1 = "familiar") and how they managed insomnia using a nine-point Likert scale (1 = "I never prescribe/perform it"; 9 = "I often prescribe/perform it"). Physicians who were unfamiliar with a management option were deemed to have never prescribed or performed it. RESULTS: Regarding medication, most physicians were familiar with novel hypnotics. Suvorexant was the most used hypnotic, followed by lemborexant and ramelteon. These novel hypnotics averaged 4.8-5.4 points and 4.0-4.7 points for sleep onset and sleep maintenance insomnia, respectively. By contrast, most benzodiazepines were seldom used below two points. Regarding psychotherapy, only approximately 40% of the physicians were familiar with cognitive behavioral therapy for insomnia (CBT-I) and they rarely implemented it, at an average of 1.5-1.6 points. More physicians were familiar with single-component psychotherapies (i.e., relaxation, sleep restriction therapy, and stimulus control) compared to CBT-I, and 48-74% of them implemented it slightly more often, with scores ranging from 2.6 to 3.4 points. CONCLUSION: This study suggests that Japanese primary care physicians seldom use CBT-I to treat insomnia. In addition, they use novel sleep medications more frequently than benzodiazepines in terms of pharmacotherapy. The use and availability of CBT-I in Japanese primary care might be facilitated by: educating primary care physicians, implementing brief or digital CBT-I, and/or developing collaborations between primary care physicians and CBT-I specialists.

Psychopathological symptoms in two generations of the same family: a cross-cultural comparison.

PURPOSE: The main aims of the present study were to compare the frequency and correlates of psychopathological symptoms in two generations of the same family in Japan and in England. METHODS: The sample included 689 adolescents and one of their parents/guardians. All participants completed a set of questionnaires to measure psychopathological symptoms, self-construals, and perceived social support. RESULTS: In both parent and adolescent data, the Japanese sample reported significantly lower psychopathological symptoms than the English sample. The relationship between parental and adolescent psychopathology was significant in England, but not in Japan. In both countries, perceived social support and independent self-construal were generally associated with less psychopathological symptoms, and interdependent self-construal was associated with more symptoms. Additionally, in England, a significant interaction effect was found between social support and the self-construals. Participants with low independent and high interdependent self-construal had elevated levels of psychopathological symptoms when perceived social support was low. CONCLUSIONS: The present study illustrates the importance of culture in the transmission of psychopathological symptoms across different generations in the same family.

Development and validation of the Japanese version of the Athens Insomnia Scale.

AIM: The aim of this study was to develop and validate a Japanese version of the Athens Insomnia Scale (AIS-J). METHODS: The AIS-J was created using a back-translation design. A total of 477 outpatients with chronic insomnia and 163 individuals from the general community were recruited. Participants were asked to complete the AIS-J along with two other insomnia scales - Japanese versions of the Pittsburgh Sleep Quality Index and the Insomnia Severity Index. RESULTS: The AIS-J consisted of a two-factor structure: 'nocturnal sleep problem' (items 1-5) and 'daytime dysfunction' (items 6-8). Internal consistencycoefficients ranged from 0.78 to 0.88. Correlations between the AIS-J and the aforementioned authorized scales were 0.81 and 0.85, respectively. Scores on the AIS-J were significantly higher for the insomnia group than for the control group. The AIS-J cut-off value for identifying pathological insomnia was estimated at 6 points or more, and the AIS-J-nocturnal cut-off value was estimated at 4 points or more. CONCLUSIONS: The AIS-J has sufficient validity and diagnostic utility.

Preliminary assessment of the behavioral activation model in Japanese undergraduate students.

Many studies have reported that behavioral activation is an effective intervention for depression. The behavioral activation model is based on several formulations. For example, depressive mood leads to avoidant behaviors, avoidance negatively affects social contacts, decreased socialization lessens opportunities for positive reinforcement, and a decrease in positive reinforcement results in more depressive mood. The purpose of this study was to examine relationships among avoidant behavior, social contact, frequency of positive reinforcement, and depressive mood by using structural equation modeling to assess support for aspects of this behavioral activation model. Participants were 630 Japanese undergraduate students and vocational school students. Results provided preliminary support for the model. Treating both avoidance and activating behavior might contribute to decreased impairment.

Association of Sleep Reactivity and Anxiety Sensitivity with Insomnia-Related Depression and Anxiety among City Government Employees in Japan.

It has recently been noted that a reduction in sleep reactivity, characterized as the trait-like degree to which exposure to stress interferes with sleep, and anxiety sensitivity are associated with reduced insomnia severity. This study aimed to examine whether sleep reactivity and anxiety sensitivity are associated with insomnia-related depression and anxiety among city government employees in Japan. This cross-sectional study included 1810 city government employees of Koka City, Japan (mean age (standard deviation): 45.33 (12.20) years) who completely answered the scales for sleep reactivity, anxiety sensitivity, anxiety, and depression. Stepwise multiple regression analysis adjusted for demographic data showed that anxiety sensitivity (ß = 0.39) was significantly linked to anxiety, and sleep reactivity (ß = 0.36) was significantly linked to depression in individuals with insomnia. Additionally, the results of a logistic regression analysis adjusted for demographic data showed that anxiety sensitivity and sleep reactivity were relevant factors for anxious insomnia (OR = 12.69) and depressive insomnia (OR = 8.73), respectively. Whereas both sleep reactivity (OR = 14.67) and anxiety sensitivity (OR = 6.14) were associated with combined insomnia. These findings indicate that sleep reactivity is strongly associated with depressive symptoms, and anxiety sensitivity is strongly associated with anxiety symptoms in individuals with insomnia.

Psychometric Properties of the Japanese Version of the Parental Acceptance and Action Questionnaire in Parents with Infants and Toddlers.

We aimed to examine the reliability and validity of the Parental Acceptance and Action Questionnaire-Japanese version (PAAQ-J). We considered a total of 2000 mothers with infants and toddlers aged 0-3 years and evaluated their scores on the PAAQ-J Acceptance and Action Questionnaire-II (AAQ-II) and Hospital Anxiety and Depression Scale (HADS). We conducted an exploratory factor analysis, creating a PAAQ-J with 12 items and three factors (α = 0.80): Inaction-Behavior, Inaction-Cognition, and Unwillingness, with α of 0.84, 0.72 and 0.68, respectively. The test-retest reliability examination results showed that the interclass correlation coefficient was 0.49, with 95% CI between 0.44 and 0.54. The correlation coefficient of PAAQ-J was 0.57, 0.32, and 0.33 with AAQ-II, and HADS-depression and HADS-anxiety, respectively. PAAQ-J's validity to adequately evaluate an individual's avoidance of experiences regarding childcare and their psychological flexibility was proven. Since the original PAAQ was for 6-18-year-old children with anxiety symptoms, it is necessary to examine its reliability and validity not only for infants and toddlers, but also for parents of older children and adolescents in the future.

Sleep Debt Mediates the Relationship between Work-Related Social Factors, Presenteeism, and Well-Being in Japanese Workers.

Sleep debt is associated with presenteeism and mental health; however, the association of sleep debt with presenteeism and well-being in the context of work-related social factors (commuting time, workdays, and working hours) has not been fully elucidated. This study aimed to examine whether work-related social factors are associated with presenteeism and well-being via sleep debt. The participant group comprised 872 full-time and 526 part-time workers (mean age: 44.65 ± 12.37 and 48.47 ± 12.93 years, respectively). For both the full-time and part-time workers, increased sleep debt was significantly associated with presenteeism (ß = -0.171; ß = -0.160) and low well-being (ß = -0.135; ß = -0.153). Notably, commuting time was significantly associated with increased sleep debt in full-time workers (ß = 0.09). In contrast, the number of workdays was significantly associated with increased sleep debt in part-time workers (ß = -0.102). Working hours were not significantly associated with sleep debt for both full- and part-time workers. These results reveal that sleep debt might lead to various risks among workers, elucidating the work-related social factors related to sleep debt. They also highlight the importance of considering work-related social factors when addressing sleep debt.

Effect of cognitive behavioral therapy for insomnia in workers: A systematic review and meta-analysis of randomized controlled trials.

Although cognitive behavioral therapy for insomnia (CBT-I) is recommended as a first-line treatment, its efficacy for workers with insomnia remains unclear. This systematic review and meta-analysis aimed to determine the effectiveness of CBT-I in the management of insomnia symptoms in workers. We searched the literature in three electronic databases, namely PubMed, PsycINFO, and Embase, and included 21 studies in the meta-analysis. Compared with the control group, CBT-I overall resulted in significant improvements in terms of severity of insomnia (g = -0.91), sleep onset latency (g = -0.62), wakefulness after sleep onset (g = -0.60), early morning awakening (g = -0.58), and sleep efficiency (g = 0.71). However, there was no improvement in the total sleep time relative to that in the control group. Furthermore, CBT-I significantly alleviated depressive (g = -0.37) and anxiety (g = -0.35) symptoms and fatigue (g = -0.47) compared with the control group. Our study findings suggest that both web-based and face-to-face CBT-I are effective interventions for managing insomnia symptoms in daytime workers, although it is important to note that only face-to-face CBT-I achieved clinically meaningful changes. The effectiveness of CBT-I for shift workers could not be determined.

Development and validation of the Japanese version of the Restorative Sleep Questionnaire in community samples.

OBJECTIVE: This study aimed to validate the Japanese version of the Restorative Sleep Questionnaire Weekly version (RSQ-W-J) and estimate the RSQ-W-J cut-off score to identify the degree of non-restorative sleep (NRS) that interferes with daytime function. METHODS: An online survey was conducted, and 513 participants (241 men, 272 women; mean age, 47.88 ± 16.66 years) completed the questionnaires. The RSQ-W-J, Multidimensional Fatigue Inventory, Athens Insomnia Scale, Patient Health Questionnaire-9, Epworth Sleepiness Scale, Sleep Debt Index, NRS and the degree of daytime dysfunction, and the diagnostic criteria for chronic insomnia were used as implementation scales. RESULTS: The RSQ-W-J was confirmed to have a single-factor structure. Both the Cronbach α coefficient and test-retest reliability of RSQ-W-J were high (α = 0.91; intraclass correlation coefficient [ICC]agreement = 0.85). The RSQ-W-J was significantly negatively correlated with the scales of fatigue, insomnia, depressive symptoms, daytime sleepiness, and sleep debt. In addition, the RSQ-W-J scores of the insomnia group, in which participants met the diagnostic criteria for chronic insomnia, NRS group, in which participants had NRS only, and sleep debt group, in which participants had sleep debt, were significantly lower than those in the normal sleep group. Furthermore, the insomnia group scored significantly lower than the sleep debt group. The RSQ-W-J cut-off score, which indicates whether or not NRS interferes with daytime function, was estimated to be 45.8 points. CONCLUSIONS: The RSQ-W-J was shown to be useful for comprehensively measuring the degree of restorative sleep.