Delayed sleep-wake phase disorder and its related sleep behaviors in the young generation.

Delayed sleep-wake phase disorder (DSWPD) is a sleep disorder in which the habitual sleep-wake timing is delayed, resulting in difficulty in falling asleep and waking up at the desired time. Patients with DSWPD frequently experience fatigue, impaired concentration, sleep deprivation during weekdays, and problems of absenteeism, which may be further complicated by depressive symptoms. DSWPD is typically prevalent during adolescence and young adulthood. Although there are no studies comparing internationally, the prevalence of DSWPD is estimated to be approximately 3% with little racial differences between Caucasians and Asians. The presence of this disorder is associated with various physiological, genetic and psychological as well as behavioral factors. Furthermore, social factors are also involved in the mechanism of DSWPD. Recently, delayed sleep phase and prolonged sleep duration in the young generation have been reported during the period of COVID-19 pandemic-related behavioral restrictions. This phenomenon raises a concern about the risk of a mismatch between their sleep-wake phase and social life that may lead to the development of DSWPD after the removal of these restrictions. Although the typical feature of DSWPD is a delay in circadian rhythms, individuals with DSWPD without having misalignment of objectively measured circadian rhythm markers account for approximately 40% of the cases, wherein the psychological and behavioral characteristics of young people, such as truancy and academic or social troubles, are largely involved in the mechanism of this disorder. Recent studies have shown that DSWPD is frequently comorbid with psychiatric disorders, particularly mood and neurodevelopmental disorders, both of which have a bidirectional association with the pathophysiology of DSWPD. Additionally, patients with DSWPD have a strong tendency toward neuroticism and anxiety, which may result in the aggravation of insomnia symptoms. Therefore, future studies should address the effectiveness of cognitive-behavioral approaches in addition to chronobiological approaches in the treatment of DSWPD.

Effects of COVID-19-Related Anxiety and Sleep Problems on Loneliness and Feelings of School Refusal in Adolescents.

Background: COVID-19-related anxiety, sleep problems, and loneliness may be risk factors for school refusal in children and adolescents. However, few studies have examined the mechanisms by which these risk factors cause school refusal. This study examined the process by which COVID-19-related anxiety, sleep problems, and loneliness cause school refusal, using structural equation modeling. Methods: In this cross-sectional questionnaire-based study, 256 (109 male, 147 female, mean age: 15.37 ± 0.48 years) senior high school students were asked to complete the Stress and Anxiety associated with Viral Epidemics-6 questionnaire to assess COVID-19-related anxiety, the Athens Insomnia Scale (AIS), Sleep Debt Index (SDI), and chronotype (MSFsc) to assess sleep problems, the Three-Item Loneliness Scale (TILS) to assess loneliness, and Feelings of School-Avoidance Scale (FSAS) to assess school refusal. Results: Structural equation modeling showed that sleep problems affected loneliness (ß = 0.52) and feelings of school refusal (ß = 0.37), and that loneliness affected feelings of school refusal (ß = 0.47). There was no significant pathway of COVID-19-related anxiety on sleep problems, loneliness, or feelings of school refusal. The indirect effect of sleep problems on feelings of school refusal through loneliness was significant. The results of hierarchical multiple regression analysis showed that AIS (ß = 0.30) and SDI (ß = 0.13) scores were associated with TILS, and AIS (ß = 0.26) and MSFsc (ß = -0.14) scores were associated with FSAS scores. Conclusion: The findings of this study showed that sleep problems affected feelings of school refusal via both direct and indirect pathways through the exacerbation of loneliness. To prevent school refusal in adolescents, addressing the indirect pathway via loneliness could be effective in improving insomnia and sleep debt, while addressing the direct pathway could be effective in improving insomnia and chronotype.

Validation of the Japanese version of Stress and Anxiety to Viral Epidemics-9 (SAVE-9) and relationship among stress, insomnia, anxiety, and depression in healthcare workers exposed to coronavirus disease 2019.

OBJECTIVE: This study aimed to validate the Japanese version of the 9-item Stress and Anxiety to Viral Epidemics scale (SAVE-9) and the relationships among the stress related to viral epidemics, insomnia, anxiety, and depression. PATIENTS/METHODS: A cross-sectional questionnaire-based study was conducted online. In total, 1000 healthcare workers (579 men, 421 women; mean age: 43.11 ± 11.69 years) were asked to complete the SAVE-9, Athens Insomnia Scale, Generalized Anxiety Disorder-7 Scale, and Center for Epidemiological Studies Depression Scale. For the analysis, participants were divided into two groups: healthcare workers at a medical institution designated for COVID-19 (COVID institution) and those working at an institution not designated for COVID-19 (non-COVID institution). RESULTS: Item response theory analysis showed that the SAVE-9 and SAVE-6 (6-item version) had good structural validity and internal consistency (ω = 0.91 and 0.93). Correlation analysis for convergent validity showed a significant positive correlation between both the SAVE-9 and SAVE-6 and the other scales for insomnia, anxiety, and depression. In addition, both SAVE-9 and SAVE-6 scores were higher for workers in COVID institutions than for those in non-COVID institutions. Furthermore, stress related to viral epidemics was found to directly affect anxiety (ß = 0.48) and depression (ß = 0.25) and indirectly affect anxiety (ß = 0.37) and depression (ß = 0.54) via insomnia (ß = 0.33). CONCLUSIONS: This study confirmed that the reliability and validity of both the SAVE-9 and SAVE-6 and that insomnia mediated the effects of stress to viral epidemics on anxiety and depression symptoms.