Nonrestorative sleep and its association with insomnia severity, sleep debt, and social jetlag in adults: Variations in relevant factors among age groups.

Objective: Nonrestorative sleep (NRS) is unrefreshing sleep that is harmful to mental and physical health. Although few studies have reported the relationship between NRS and sleep problems, none have evaluated this relationship by age group. This study aimed to determine whether NRS could be associated with insomnia severity, sleep debt, and social jetlag and whether this relationship would vary with age.

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.

Network analysis to estimate central insomnia symptoms among daytime workers at-risk for insomnia.

Although insomnia complaints are associated with mental health problems and reduced work productivity, the central insomnia symptoms in workers at-risk for insomnia remain unclear. This study aimed to identify the central insomnia symptoms among daytime workers at risk for insomnia. The participants were 881 Japanese daytime workers at-risk for insomnia with a mean age of 49.

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.

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.

Impact of sleep debt, social jetlag, and insomnia symptoms on presenteeism and psychological distress of workers in Japan: a cross-sectional study.

Background: Presenteeism is an indicator of productivity loss and the risk of absence from work due to mental health problems. The purpose of this study was to determine the impact of sleep debt, social jetlag, and insomnia symptoms on presenteeism and psychological distress.

Methods: The participants were 351 Japanese workers (271 males, 79 females, and one of other gender, with a mean age of 49 ± 9.