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.

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.

Limited social support is associated with depression, anxiety, and insomnia in a Japanese working population.

Background: Lack of social support is associated with depression, anxiety, and insomnia. This study aimed to determine the source of support related to depression, anxiety, and insomnia among Japanese workers. Methods: As part of a cohort study, we conducted a questionnaire survey among city government employees in Koka City, Shiga Prefecture, Japan, from September 2021 to March 2022. We used the Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and Insomnia Severity Index (ISI) to assess depressive symptoms, anxiety symptoms, and insomnia, respectively. We used the Brief Job Stress Questionnaire (BJSQ) to assess job stressors and social support (from supervisors, colleagues, and family). Results: A total of 1,852 Japanese employees (38.4% male, 45.9 ± 12.9 years) participated in the survey, with 15.5, 10.8, and 8.2% of the participants having depressive symptoms (PHQ-9 ≥ 10), anxiety symptoms (GAD-7 ≥ 10), and insomnia (ISI ≥ 15), respectively. The logistic regression analysis suggested that job stressors were associated with depressive symptoms (p < 0.001), anxiety symptoms (p < 0.001), and insomnia (p = 0.009). In contrast, support from co-workers (p = 0.016) and family members (p = 0.001) was associated with decreased depressive symptoms. Support from family members was associated with decreased insomnia (p = 0.005). Conclusion: Social support from co-workers and family may be associated with reduced depressive symptoms, and family support may be associated with reduced insomnia in the Japanese working population. Clinical trial registration: https://clinicaltrials.gov/ct2/show/NCT03276585.

Obstructive Sleep Apnoea Severity Is Negatively Associated with Depressive Symptoms: A Cross-Sectional Survey of Outpatients with Suspected Obstructive Sleep Apnoea in Japan.

Background: Multiple clinical departments are involved in the provision of obstructive sleep apnoea (OSA) therapy in Japan. Inconsistent results regarding the association between depression and OSA have been reported. Methods: This cross-sectional survey compared newly diagnosed OSA patients at two outpatient sleep apnoea units in Shiga Prefecture, Japan: one associated with the psychiatry department (n = 583), and the other with the otolaryngology department (n = 450). Results: The unit associated with the psychiatry department had more patients referred by psychiatrists than that with the otolaryngology department (11% vs. 3% p < 0.05). Sleepiness, insomnia, and depression were assessed using the Epworth Sleepiness Scale (ESS), Athens Insomnia Scale (AIS), and Patient Health Questionnaire-9 (PHQ-9), respectively. The ESS, AIS, and PHQ-9 scores were higher in the sleep unit in the psychiatry department (p < 0.001 each). Snoring and moderate to severe OSA were more prevalent in the unit attached to the otolaryngology department (p < 0.001 each). Patients with moderate to severe OSA had lower PHQ-9 scores than those with no to mild OSA (OR: 0.96, 95% CI: 0.92−1.00, p = 0.042). Conclusion: Patients with sleepiness, insomnia, and depressive symptoms were more likely to attend a sleep outpatient unit associated with a psychiatry department, whereas those with snoring and sleep apnoea attended that associated with an otolaryngology department. OSA severity was negatively associated with depressive symptoms.

How Does E-mail-Delivered Cognitive Behavioral Therapy Work for Young Adults (18-28 Years) with Insomnia? Mediators of Changes in Insomnia, Depression, Anxiety, and Stress.

This study examined whether cognitive behavioral therapy (CBT) for insomnia (CBT-I) improved insomnia severity, by changing sleep-related mediating factors. It also examined whether an improvement in insomnia led to enhanced mental health. This study was a secondary analysis of a randomized controlled trial of e-mail-delivered CBT-I for young adults with insomnia. The participants were randomized to either CBT-I or self-monitoring. The mental health-related measures were depression, anxiety, and stress. The sleep-related mediating factors were sleep hygiene practices, dysfunctional beliefs, sleep reactivity, and pre-sleep arousal. A total of 41 participants, who completed all the sessions (71% females; mean age 19.71 ± 1.98 years), were included in the analysis. The hierarchical multiple regression analysis showed that 53% of the variance in the improvements in insomnia severity was explained by the treatment group (ß = −0.53; ΔR2 = 0.25; p < 0.01) and the changes in sleep reactivity (ß = 0.39; ΔR2 = 0.28; p < 0.05). Moreover, the mediation analysis showed that the reductions in depression and stress were explained by the changes in insomnia severity; however, anxiety symptoms were not reduced. CBT-I for young adults suggested that sleep reactivity is a significant mediator that reduces insomnia severity, and that the alleviation and prevention of depression and stress would occur with the improvement in insomnia.

Prolonged Sleep Latency and Reduced REM Latency Are Associated with Depressive Symptoms in a Japanese Working Population.

BACKGROUND: Examining the relationship between sleep and depression may be important for understanding the aetiology of affective disorders. Most studies that use electroencephalography (EEG) to objectively assess sleep have been conducted using polysomnography in the laboratory. Impaired sleep continuity, including prolonged sleep latency and changes in rapid eye movement (REM) sleep, have been reported to be associated with depression in clinical settings. Here, we aimed to use home EEG to analyse the association between sleep and depressive symptoms. METHODS: We performed a cross-sectional epidemiological study in a large Japanese working population to identify the EEG parameters associated with depressive symptoms based on the results of a questionnaire survey and home EEG measurements using 1-channel (1-Ch) EEG. RESULTS: The study included 650 Japanese patients (41.2% male, 44.7 ± 11.5 years) who underwent home EEG monitoring along with the Patient Health Questionnaire-9 (PHQ-9) to assess depressive symptoms. Logistic regression analysis revealed that depressive symptoms (PHQ-9 ≥ 10) were associated with sleep latency (odds ratio (OR) 1.02; 95% confidence interval (CI): 1.00-1.04) and REM latency (OR, 0.99; 95% CI: 0.99-1.00). CONCLUSIONS: Our results suggest that depressive symptoms are associated with prolonged sleep latency and reduced REM latency in a Japanese working population. The 1-Ch EEG may be a useful tool to monitor sleep and screen depression/depressive symptoms in non-clinical settings.

Minor hallucinations in isolated rapid eye movement sleep behavior disorder indicative of early phenoconversion: A preliminary study.

OBJECTIVES: Minor hallucinations (MH) are psychotic symptoms that can occur anywhere between prodromal to early Parkinson's disease and after onset of motor problems. MH include visual illusions, presence hallucinations, and passage hallucinations. Isolated rapid eye movement sleep behavior disorder (RBD) is a harbinger of neurodegenerative diseases. We conducted a retrospective cohort study to investigate the clinical characteristics of isolated RBD with MH and the risk of phenoconversion. MATERIALS AND METHODS: We retrospectively analyzed the data of 36 patients with isolated RBD (four females; median age, 75.0 years). We defined cases reporting at least one minor hallucination as RBD with MH. Demographic data and cognitive function were compared between patients with and without MH, and Cox proportional hazards models estimated the risk of phenoconversion. RESULTS: We included 10 (27.8%) patients with MH and 26 (72.2%) without MH. Patients with MH were older, had less dopamine transporter accumulation, more severe autonomic dysfunction, more depressive symptoms, and lower verbal fluency and symbol coding test scores than patients without MH. After follow-up (median, 2.50 years), 13.9% (5/36) of all patients developed phenoconversion (Parkinson's disease, two patients; dementia with Lewy bodies, three patients). The rate of phenoconversion was significantly higher in patients with MH (40.0% vs. 3.8%, p = .005). The Cox proportional hazards model adjusted for age, sex, and disease duration revealed that MH was a significant risk factor for phenoconversion (hazard ratio, 14.72; 95% confidence interval, 1.35-160.5). CONCLUSIONS: Minor hallucinations may be utilized as early clinical markers for prodromal estimation of neurodegenerative diseases.

Large Questionnaire Survey on Sleep Duration and Insomnia Using the TV Hybridcast System by Japan Broadcasting Corporation (NHK).

BACKGROUND: Japanese people are known to have the shortest sleep duration in the world. To date, no study has assessed a large Japanese population for insomnia and sleep duration. METHODS: We performed an Ιnternet-based survey in association with a national television (TV) program. Questionnaire data were collected not only through personal computers, tablets, and smartphones, but also through the Hybridcast system, which combines broadcasts over airwaves with broadband data provided via the Internet using the TV remote controller. The Athens Insomnia Scale (AIS) was used to assess insomnia. RESULTS: A total of 301,241 subjects participated in the survey. Participants slept for an average of 5.96 ± 1.13 h; the average AIS score was 6.82 ± 3.69. A total of 26.1% of male and 27.1% of female participants had both insomnia (AIS ≥ 6) and short sleep duration (<6 h). Responses were recorded through the Hybridcast system for 76.4% of the elderly (age ≥ 65 years) subjects and through personal computers, tablets, or smartphones for 59.9-82.7% of the younger subjects (age ≤ 65 years). CONCLUSIONS: Almost a quarter of the Japanese participants presented short sleep duration and insomnia. Furthermore, the Hybridcast system may be useful for performing large internet-based surveys, especially for elderly individuals.

Self-Isolation Due to COVID-19 Is Linked to Small One-Year Changes in Depression, Sleepiness, and Insomnia: Results from a Clinic for Sleep Disorders in Shiga Prefecture, Japan.

We aimed to analyze (a) the changes in depression, sleepiness, insomnia, and sleep habits in relation to the degree of self-isolation and (b) the effects of changes in sleep habits and social interactions on depression, insomnia, and sleepiness during the coronavirus disease 2019 (COVID-19) pandemic. We enrolled 164 patients who visited the sleep outpatient clinic in Shiga University of Medical Science Hospital. We compared the sleep habits, depression (Patient Health Questionnaire-9: PHQ-9), insomnia (Athens Insomnia Scale: AIS), and sleepiness (Epworth Sleepiness Scale: ESS) of patients during the period from April to July 2019 vs. May 2020 (a period of self-isolation due to COVID-19). A Wilcoxon signed-rank test indicated no significant differences in PHQ-9, ESS, and AIS scores between 2019 and 2020 within both the strong self-isolation group and no/little self-isolation group. With respect to sleep habits, earlier bedtime (p = 0.006) and increased sleep duration (p = 0.014) were found in the strong self-isolation group. The former (p = 0.009) was also found in the no/little self-isolation group, but we found significant differences in sleep duration between the no/little self-isolation group and the strong self-isolation group (p = 0.047). Therefore, self-isolation due to COVID-19 had relatively small one-year effects on depression, sleepiness, and insomnia in a clinical population.

Evaluation of Severity Levels of the Athens Insomnia Scale Based on the Criterion of Insomnia Severity Index.

The Athens Insomnia Scale (AIS) can be regarded as a highly useful instrument in both clinical and research settings, except for when assessing the severity level. This study aims to determine the severity criteria for AIS by using the Insomnia Severity Index (ISI). A total of 1666 government employees aged 20 years or older were evaluated using the AIS and ISI, the Patient Health Questionnaire for depressive symptoms, the Epworth Sleepiness Scale for daytime sleepiness, and the Short Form Health Survey of the Medical Outcomes Study for health-related quality of life (QoL). A significant positive correlation (r) was found between the AIS and the ISI (r = 0.80, p < 0.001). As a result of describing receiver-operator curves, the severity criteria of the AIS are capable of categorizing insomnia severity as follows: absence of insomnia (0-5), mild insomnia (6-9), moderate insomnia (10-15), and severe insomnia (16-24). In addition, compared to all scales across groups categorized by AIS or ISI, it was revealed that similar results could be obtained (all p < 0.05). Therefore, the identification of the severity of AIS in this study is important in linking the findings of epidemiological studies with those of clinical studies.