A cognitive model of insomnia

Gender differences in sleep quality among Iranian traditional and industrial drug users

•The findings emphasize gender differences in sleep quality among different cultures, races, and ethnicities.•There are gender differences in sleep quality in Iranian traditional and industrial drug users.•Industrial drug users have a lower quality of sleep than traditional drug users.•The sleep quality of drug users (traditional and industrial) is lower than that of healthy people.

Randomized controlled trial of cognitive refocusing versus stimulus control treatment for college insomnia: feasibility of a brief, electronic-based, and peer-led approach

OBJECTIVE

Performance of Cognitive Refocusing Treatment for Insomnia (CRT-I) relative to stimulus control treatment (SCT) remains unknown among college students. This pilot trial compared single-session, electronic-based, peer-led CRT-I to SCT, and as well as awareness-based (AC) and no-treatment (NTC) controls.

PARTICIPANTS

College students (N = 82; Mage=18.59 [SD = 0.78]; 58% female; 61% White; 16% Hispanic) with insomnia symptoms were randomly assigned to CRT-I (n = 12), SCT (n = 14), and AC (n = 14) conditions, or non-randomly recruited to NTC (n = 42).

METHODS

All participants completed baseline and one-month follow-up surveys, and reported daily task enactment (except NTC).

RESULTS

Feasibility ratings were comparable across conditions. Within-group treatment effects revealed greater improvements in (a) insomnia symptom severity among CRT-I (d = 1.13) and SCT (d = 1.66) groups relative to AC (d = 0.90) and (b) pre-sleep cognitive arousal among CRT-I (d = 0.94) and SCT (d = 1.42) groups relative to AC (d = 0.75).

CONCLUSIONS

Brief, electronic-based, peer-led CRT-I and SCT interventions appear feasible and potentially efficacious for college insomnia.

A randomized controlled trial modifying insomnia-consistent interpretation bias in students

This study aimed to determine the causal role of insomnia-consistent interpretation bias within the cognitive model of insomnia, by modifying this bias in students experiencing subclinical levels of insomnia and assessing subsequent effects on sleep parameters. A sample of 128 students underwent randomization to receive either a single session of online Cognitive Bias Modification-Interpretation (CBM-I) or a sham training. Participants then tracked their pre-sleep worry and sleep parameters for seven consecutive days. Interpretation bias was assessed using an encoding-recognition task specifically designed for insomnia-related interpretation bias. The CBM-I manipulation utilized ambiguous scenarios to redirect participants away from making insomnia-related interpretations. Results revealed that CBM-I effectively decreased insomnia-consistent interpretation bias compared to the sham treatment, with interpretation bias being absent post-training in the CBM-I group. This reduction did not lead to improvements in pre-sleep worry or any sleep parameters. This study has been the first to investigate the causal role of interpretation bias on symptoms of insomnia. Although results indicated this bias to be modifiable, its causality within the cognitive model proves to be more complicated. Future research focusing on optimization of cognitive bias modifications could shed more light on the effects of biased cognitions on insomnia symptoms.

Digital cognitive behavioural therapy for insomnia versus digital sleep education control in an Australian community-based sample: a randomised controlled trial

BACKGROUND

Insomnia is a prevalent condition in Australia that increases the risk of depression and anxiety symptoms. Cognitive behaviour therapy for insomnia (CBT-i) is the recommended 'first line' treatment but is accessed by a minority of people with insomnia.

AIMS

To improve CBT-i access in Australia, we aimed to develop and test a self-guided interactive digital CBT-i program.

METHODS

An online randomised controlled trial was conducted from August 2022 to August 2023 to investigate the effect of digital CBT-i, versus digital sleep education control, on symptoms of insomnia (ISI), depression (PHQ-9), anxiety (GAD-7), fatigue, sleepiness and maladaptive beliefs about sleep at 8-week follow-up. The control group accessed the intervention after the 8-week follow-up. Questionnaires were additionally administered at 16 and 24 weeks. Intent-to-treat mixed models and complete-case chi-squared analyses were used.

RESULTS

Participants included 62 adults with insomnia symptoms (age M (SD) = 52.5 (16.3), 82% female, ISI = 18.6 (2.9)). There were no between-group differences in baseline characteristics or missing 8-week data (14.5%). After adjusting for baseline scores, CBT-i was associated with lower insomnia (Diffadj (95% CI) = 7.32 (5.0-9.6), P < 0.001, d = 1.64), depression (3.36 (1.3-5.4), p = 0.002, d = 0.84), fatigue (5.2 (2.5-7.9), P < 0.001, d = 1.00) and maladaptive beliefs about sleep (11.0 (4.1-18.0), P = 0.002, d = 0.82), but not anxiety symptoms at 8 weeks (1.84 (-0.1 to 3.8), p = 0.060, d = 0.50). Compared to control, CBT-i was associated with greater rates of insomnia remission (ISI <8; 0.0%, vs 40.0%, P < 0.001) and response at 8 weeks (ISI reduction ≥6; 7.1% vs 72.0%, P < 0.001). Improvements in insomnia and depression were maintained at 24 weeks in the CBT-i group.

CONCLUSIONS

This interactive digital CBT-i program resulted in large and sustained improvements in symptoms of insomnia, depression, fatigue and maladaptive beliefs about sleep in Australian adults with insomnia symptoms. Implementation programs are required to increase digital CBT-i access and uptake.

The mediating effect of sleep quality on solid cooking fuel use and psychological distress among rural older adults: evidence from Shandong, China

BACKGROUND

Exposure to indoor air pollution from solid cooking fuel use may increase mental disorders risk through pathways such as oroxidative stress, neuroinflammation, or cerebrovascular damage. However, few studies have explored the underlying mechanism between solid cooking fuel use and psychological distress. The present study aims to investigate the mediating role of sleep quality on the relationship between solid cooking fuel use and psychological distress among older adults in rural Shandong, China.

METHODS

This study used the cross-sectional data from the second follow-up survey of the Shandong Rural Elderly Health Cohort (SREHC). A total of 3,240 rural older adults were included in the analysis. Logistic regression and the Karlson, Holm, and Breen (KHB) mediation analyses were performed to investigate the relationship between solid cooking fuel use and psychological distress, as well as the mediating role of sleep quality in this association.

RESULTS

This study found that solid cooking fuel use was significantly and positively associated with psychological distress among older adults in rural Shandong, China (OR = 1.38, 95% CI: 1.12,1.70). Mediation analysis revealed that sleep quality mediated the association between solid cooking fuel use and psychological distress among older adults (β = 0.06, P = 0.011). The mediation effect accounted for 16.18% of the total effect.

CONCLUSIONS

Our study showed that solid cooking fuel use was associated with psychological distress among rural older adults, and sleep quality mediated this association. Interventions should focus on addressing cooking fuel types and poor sleep quality to reduce psychological distress. In the future, more aggressive environmental protection policies would be needed to lessen the adverse effects of indoor air pollution on the health of older adults in rural China.

Effects of perceived stress on college students' sleep quality: a moderated chain mediation model

BACKGROUND

Perceived Stress has been shown as a key contributor to sleep quality, but the underlying mechanism between perceived stress and sleep quality remains unknown. This study aimed to investigate the impact of perceived stress on sleep quality of college students and the chain mediating roles of presence of meaning in life (PML) and depression, as well as the moderating role of search for meaning in life (SML).

METHODS

Participants were 8178 college students (4599 boys and 3579 girls; Mage = 19.10 years, SD = 1.08) who completed self-report questionnaire, including the Perceived Stress Scale (PSS), the Pittsburgh Sleep Quality Index (PSQI), the Meaning in Life Questionnaire (MLQ), and the Patient Health Questionnaire-9 (PHQ-9).

RESULTS

The results showed that higher perceived stress was directly related to poorer sleep quality. This negative impact on sleep quality was mediated through the chained roles of PML and depression. Additionally, the study found that SML moderates the influence of perceived stress, PML and depression on sleep quality. Specifically, for individuals actively search for meaning, the adverse effects of perceived stress and depression on sleep quality are diminished. Concurrently, the positive influence of PML on sleep quality is enhanced.

CONCLUSION

This study revealed that the PML and depression mediate the effect of perceived stress on sleep quality, with SML playing a significant protective role. These results emphasize the necessity of integrating strategies to enhance PML and SML into interventions designed to improve emotion management and sleep quality among college students.

Perfect Enough to Sleep? Perfectionism and Actigraphy-Determined Markers of Insomnia

OBJECTIVES

Perfectionism is an important factor in insomnia development and maintenance. Previous studies exploring the relationship between perfectionism and insomnia have predominantly relied on self-reported sleep measures. Therefore, this study sought to assess whether actigraphy-measured sleep parameters were associated with perfectionism.

METHODS

Sixty adults (85% females, mean age 30.18 ± 11.01 years) were sampled from the Australian general population. Actigraphy-derived objective sleep measures, subjective sleep diary measures, the Frost Multidimensional Perfectionism Scale (FMPS), Hewitt-Flett Multidimensional Perfectionism Scale (HFMPS) and Depression, Anxiety and Stress Scale 21 (DASS-21) were collected.

RESULTS

High perfectionism levels were associated with poor sleep, but these relationships differed between objective and subjective measures. Perfectionism via FMPS total score and subscales of Concern over Mistakes, Doubts about Actions, Personal Standards and Self-oriented Perfectionism correlated with subjective sleep onset latency and sleep efficiency with moderate effects (r = .26 to .88). In contrast, perfectionism via HFMPS total score and subscales of Socially Prescribed Perfectionism and Parental Expectations predicted objective sleep onset latency and sleep efficiency. Additionally, stress mediated the relationships between objective sleep efficiency and Concern over Mistakes and Doubts about Actions.

CONCLUSIONS

Perfectionism demonstrated stronger associations with subjective than objective sleep measures. Higher Parental Expectations and Socially Prescribed Perfectionism may increase one's vulnerability to objectively measured poor sleep. Therefore, perfectionism may be important in preventing and treating insomnia.

Evaluation of the effectiveness of cognitive behavioral therapy on tinnitus

OBJECTIVE

This research aims to examine the effects of Cognitive Behavioral Therapy (CBT) on tinnitus in individuals aged 18-60 years.

METHODS

Thirty participants with subjective tinnitus for at least six months were included a randomized controlled trial was conducted with 15 participants in the experimental group and 15 in the control group, with pre-test and post-test measurements. The experimental group received eight CBT sessions for eight weeks. Data were collected using Tinnitus Handicap Inventory (THI) and Visual Analog Scale (VAS). The Mann-Whitney and Wilcoxon Signed Rank Test were used to compare scores between experimental and control groups before and after the intervention.

RESULTS

A within-group difference was found between total scores on THI and VAS before and after CBT in the experimental (z = -3.241, P = 0.001), but not in the control group (z = -1.764, P = 0.078). Following the intervention, there was a significant between-group difference on the THI Emotional, Catastrophic, and Functional tinnitus subscale scores, favoring the experimental group.

CONCLUSIONS

CBT significantly reduced tinnitus level, severity, duration, frequency, discomfort, tinnitus-related attention deficit, and sleep problems. Further studies are needed to replicate these results in other populations.

Examining the influence of problematic internet use on sleep quality in Chinese adolescents: a study using the extended Stressor-Strain-Outcome (SSO) model

Objective

This study aims to explore how problematic internet use may affect the sleep quality of Chinese adolescents using the extended Stressor-Strain-Outcome (SSO) model. The model posits that stressors indirectly influence behavioral outcomes through the mediation of emotional and physiological strain responses.

Method

A sample of 4,365 adolescents in China participated in this study, which utilized questionnaires and other methods to develop a novel SSO model. In this model, problematic internet use was considered as the stressor, anxiety as an indicator of tension, and sleep quality as the ultimate outcome. Family health was introduced as a moderating variable.

Results

The study found that problematic internet use can significantly and positively predict adolescents' anxiety (β = 0.132, p < 0.001) and sleep quality (β = 0.362, p < 0.001). Furthermore, anxiety was identified as a significant mediating factor between problematic internet use and sleep quality [Effect = 0.066, p < 0.05, 95% CI (0.014, -0.0018)]. Family health was observed to have a moderating effect on the relationship between problematic internet use and anxiety (β = -0.075, p < 0.001).

Conclusion

The research indicates that problematic internet use not only directly increases individual anxiety as a stressor but also indirectly impacts sleep quality by exacerbating anxiety. However, a positive family health status can effectively moderate the adverse impact of problematic internet use on anxiety.

Assessing the Short-Term Efficacy of Digital Cognitive Behavioral Therapy for Insomnia With Different Types of Coaching: Randomized Controlled Comparative Trial

BACKGROUND

Digital cognitive behavioral therapy for insomnia (dCBTi) is an effective intervention for treating insomnia. The findings regarding its efficacy compared to face-to-face cognitive behavioral therapy for insomnia are inconclusive but suggest that dCBTi might be inferior. The lack of human support and low treatment adherence are believed to be barriers to dCBTi achieving its optimal efficacy. However, there has yet to be a direct comparative trial of dCBTi with different types of coaching support.

OBJECTIVE

This study examines whether adding chatbot-based and human coaching would improve the treatment efficacy of, and adherence to, dCBTi.

METHODS

Overall, 129 participants (n=98, 76% women; age: mean 34.09, SD 12.05 y) whose scores on the Insomnia Severity Index [ISI] were greater than 9 were recruited. A randomized controlled comparative trial with 5 arms was conducted: dCBTi with chatbot-based coaching and therapist support (dCBTi-therapist), dCBTi with chatbot-based coaching and research assistant support, dCBTi with chatbot-based coaching only, dCBTi without any coaching, and digital sleep hygiene and self-monitoring control. Participants were blinded to the condition assignment and study hypotheses, and the outcomes were self-assessed using questionnaires administered on the web. The outcomes included measures of insomnia (the ISI and the Sleep Condition Indicator), mood disturbances, fatigue, daytime sleepiness, quality of life, dysfunctional beliefs about sleep, and sleep-related safety behaviors administered at baseline, after treatment, and at 4-week follow-up. Treatment adherence was measured by the completion of video sessions and sleep diaries. An intention-to-treat analysis was conducted.

RESULTS

Significant condition-by-time interaction effects showed that dCBTi recipients, regardless of having any coaching, had greater improvements in insomnia measured by the Sleep Condition Indicator (P=.003; d=0.45) but not the ISI (P=.86; d=-0.28), depressive symptoms (P<.001; d=-0.62), anxiety (P=.01; d=-0.40), fatigue (P=.02; d=-0.35), dysfunctional beliefs about sleep (P<.001; d=-0.53), and safety behaviors related to sleep (P=.001; d=-0.50) than those who received digital sleep hygiene and self-monitoring control. The addition of chatbot-based coaching and human support did not improve treatment efficacy. However, adding human support promoted greater reductions in fatigue (P=.03; d=-0.33) and sleep-related safety behaviors (P=.05; d=-0.30) than dCBTi with chatbot-based coaching only at 4-week follow-up. dCBTi-therapist had the highest video and diary completion rates compared to other conditions (video: 16/25, 60% in dCBTi-therapist vs <3/21, <25% in dCBTi without any coaching), indicating greater treatment adherence.

CONCLUSIONS

Our findings support the efficacy of dCBTi in treating insomnia, reducing thoughts and behaviors that perpetuate insomnia, reducing mood disturbances and fatigue, and improving quality of life. Adding chatbot-based coaching and human support did not significantly improve the efficacy of dCBTi after treatment. However, adding human support had incremental benefits on reducing fatigue and behaviors that could perpetuate insomnia, and hence may improve long-term efficacy.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05136638; https://www.clinicaltrials.gov/study/NCT05136638.

Sleep disturbances and psychological well-being among military medical doctors of the Swiss Armed Forces: study protocol, rationale and development of a cross-sectional and longitudinal interventional study

Background

Compared to civilians and non-medical personnel, military medical doctors are at increased risk for sleep disturbances and impaired psychological well-being. Despite their responsibility and workload, no research has examined sleep disturbances and psychological well-being among the medical doctors (MDs) of the Swiss Armed Forces (SAF). Thus, the aims of the proposed study are (1) to conduct a cross-sectional study (labeled 'Survey-Study 1') of sleep disturbances and psychological well-being among MDs of the SAF; (2) to identify MDs who report sleep disturbances (insomnia severity index >8), along with low psychological well-being such as symptoms of depression, anxiety and stress, but also emotion regulation, concentration, social life, strengths and difficulties, and mental toughness both in the private/professional and military context and (3) to offer those MDs with sleep disturbances an evidence-based and standardized online interventional group program of cognitive behavioral therapy for insomnia (eCBTi) over a time lapse of 6 weeks (labeled 'Intervention-Study 2').

Method

All MDs serving in the SAF (N = 480) will be contacted via the SAF-secured communication system to participate in a cross-sectional survey of sleep disturbances and psychological well-being ('Survey-Study 1'). Those who consent will be provided a link to a secure online survey that assesses sleep disturbances and psychological well-being (depression, anxiety, stress, coping), including current working conditions, job-related quality of life, mental toughness, social context, family/couple functioning, substance use, and physical activity patterns. Baseline data will be screened to identify those MDs who report sleep disturbances (insomnia severity index >8); they will be re-contacted, consented, and randomly assigned either to the eCBTi or the active control condition (ACC) ('Intervention-Study 2'). Individuals in the intervention condition will participate in an online standardized and evidence-based group intervention program of cognitive behavioral therapy for insomnia (eCBTi; once the week for six consecutive weeks; 60-70 min duration/session). Participants in the ACC will participate in an online group counseling (once the week for six consecutive weeks; 60-70 min duration/session), though, the ACC is not intended as a bona fide psychotherapeutic intervention. At the beginning of the intervention (baseline), at week 3, and at week 6 (post-intervention) participants complete a series of self-rating questionnaires as for the Survey-Study 1, though with additional questionnaires covering sleep-related cognitions, experiential avoidance, and dimensions of self-awareness.

Expected outcomes

Survey-Study 1: We expect to describe the prevalence rates of, and the associations between sleep disturbances (insomnia (sleep quality); sleep onset latency (SOL); awakenings after sleep onset (WASO)) and psychological well-being among MDs of the SAF; we further expect to identify specific dimensions of psychological well-being, which might be rather associated or non-associated with sleep disturbances.Intervention-Study 2: We expect several significant condition-by-time-interactions. Such that participants in the eCBTi will report significantly greater improvement in sleep disturbances, symptoms of depression, anxiety, stress reduction both at work and at home (family related stress), and an improvement in the overall quality of life as compared to the ACC over the period of the study.

Conclusion

The study offers the opportunity to understand the prevalence of sleep disturbances, including factors of psychological well-being among MDs of the SAF. Further, based on the results of the Intervention-Study 2, and if supported, eCBTi may be a promising method to address sleep disturbances and psychological well-being among the specific context of MDs in the SAF.

Preoccupation with sleep and dysfunctional beliefs about sleep mediate the influence of psychological inflexibility on insomnia in the older adult population

INTRODUCTION

This study aimed to explore whether the Discrepancy between the desired time in Bed and the desired total Sleep Time (DBST) index influences insomnia severity in the older adult population and examined the potential role of psychological inflexibility in this association.

METHODS

An online survey study was conducted for older individuals aged ≥ 65 via a survey company between January and February 2023. A total of 300 responses and data without personally identifiable information were delivered to the researchers. The survey questionnaires include the DBST, Glasgow Sleep Effort Scale (GSES), Insomnia Severity Index (ISI), Dysfunctional Beliefs about Sleep-2 items (DBS-2), and Acceptance and Action Questionnaire-II (AAQ-II).

RESULTS

The analysis included 295 older adult participants. The DBST index was significantly correlated with all questionnaires. Linear regression revealed the DBST index was predicted only by the ISI (β = 0.26, p = 0.003). Mediation analysis showed that the GSES (Z = 2.92, p = 0.003) and DBS-2 (Z = 2.17, p = 0.030) mediated the effect of the DBST index on the ISI, while the AAQ-II did not. Path analysis showed that the DBST could be directly predicted by the ISI (Z = 2.94, p = 0.003), GSES (Z = 2.75, p = 0.006), and DBS2 (Z = 2.71, p = 0.007) but not by the AAQ-II itself. However, the AAQ-II exerted a significant indirect effect on the ISI through the DBS-2 (Z = 2.21, p = 0.027) and GSES (z = 2.24, p = 0.025).

CONCLUSIONS

Our study showed that preoccupation and dysfunctional beliefs about sleep may mediate the relationship between the DBST index and insomnia severity in the older adult population. We opine that psychological inflexibility might play a significant role in insomnia severity via preoccupation with and dysfunctional beliefs about sleep.

The differing relationships between academic discipline, sleep hygiene, and dysfunctional sleep attitudes on sleep quality and duration in Canadian university students

Objectives

This study sought to understand how university student's academic discipline relates to sleep factors including attitudes, hygiene, quality, and duration.

Methods

Using a cross-sectional approach, a 30-min survey was advertised to students at two Canadian universities in March of 2022. Sleep measures included the Dysfunctional Beliefs and Attitudes Scale, the Sleep Hygiene Index, the Pittsburgh Sleep Quality Index, and the Insomnia Severity Index. Academic discipline was categorized into four groups: Health, Arts, Sciences, and Engineering. Multiple linear regressions were used to investigate (1) the effect of academic discipline on sleep measures, and (2) the effect of academic discipline, dysfunctional sleep attitudes, and sleep hygiene practices on insomnia, sleep quality and duration.

Results

1,566 students completed the survey (69.4% women; 80.3% undergraduates). Compared to Health students, Art students had worse dysfunctional sleep attitudes, hygiene, quality, and insomnia severity (p < 0.001). This relationship disappeared after controlling for differences in mental health (p ≥ 0.05). Art students had longer sleep durations (p < 0.01), whereas Engineering students had shorter sleep durations (p < 0.05). When dysfunctional sleep attitudes and hygiene were included in the model, both academic discipline (p < 0.05) and sleep hygiene (p < 0.001) were associated with sleep duration. Sleep hygiene and attitudes were also associated with sleep quality and insomnia severity (p < 0.001), while academic discipline was not (p ≥ 0.05).

Discussion

These results suggest differences in sleep quality across academic discipline are impacted by dysfunctional sleep attitudes, sleep hygiene, and mental health, whereas differences in sleep duration appear to be independent of these factors. Overall, students in different academic disciplines have unique relationships with sleep and thus may require targeted approaches to improve their sleep. Future interventions should focus on supporting sleep hygiene and attitudes to improve students' sleep and well-being.

Self-rated health and its bidirectional relationship with burnout, sleep quality and somatic symptoms in a general adult population

The aim of this study was to investigate how self-rated health (SRH) reflects ongoing ill-health and how SRH is associated with previous ill-health and/or predicts future ill-health such as burnout, disturbed sleep, and somatic symptoms. The study used two waves from the population-based Västerbotten Environmental and Health Study in which 2 336 adult persons participated by answering a questionnaire at two time points three years apart. Hierarchical and logistic regression analyses were conducted, thus treating all variables both continuously (degree) and categorically (case). The analyses were performed both cross-sectionally and longitudinally. The results showed bidirectionality between suboptimal SRH and burnout, disturbed sleep and somatic severity caseness. Moreover, degree of poor SRH was more likely to occur simultaneously to high degrees of burnout and somatic severity than to degree of poor sleep quality. Also, caseness of burnout, disturbed sleep and somatic severity increased the risk of simultaneous suboptimal SRH. Finally, the results showed that degree of burnout three years earlier, predicted degree of poor SRH, and that degree of poor SRH predicted degree of sleep three years later. In conclusion, in a population-based, normal adult sample there is a bidirectional relationship between suboptimal SRH and caseness of burnout, disturbed sleep quality and somatic symptoms, but not between degree of these symptoms. The results can have implications for health care meeting patients complaining about poor general health.

Negative attention bias and attentional control as mechanisms in the association between insomnia and depression in young people

Evidence supports a causal role of insomnia in the development and maintenance of depression, yet mechanisms underlying this association in young people are not well established. Attention biases have been implicated separately in the sleep and depression fields and represents an important candidate mechanism. Poor sleep may lead to a negative attention bias (characteristic of depression) by impacting attentional control. This study assessed the hypothesis that attentional control and negative attention bias would sequentially mediate the relationship between insomnia and depressive symptoms in an unselected sample of young people (17-24 years). Concerns have been raised regarding the psychometric properties of tasks used to measure attention bias, and a Dual-Probe Task is emerging as a more reliable measure. Participants (N = 275, Male = 59, Mage = 19.40) completed the Dual-Probe Task, a behavioural measure of attentional control, and self-report measures of insomnia and depression. Participants completed a one-week sleep diary. Results were consistent with negative attention bias, but not attentional control, as a mechanism which partially accounts for the relationship between sleep (i.e., insomnia severity, sleep duration, sleep efficiency, sleep latency) and depression. This study highlights sleep and negative attention bias as potentially modifiable risk factors to reduce depressive symptoms in young people.

Factors associated with workaholism in nurses' mental health: integrative review

OBJECTIVE

to synthesize the main scientific evidence available on the factors associated with workaholism in nurses' mental health.

METHOD

this is an integrative review carried out in seven databases. The sample consisted of 11 studies. The Level of Evidence classification followed the model described by Melnyk and Fineout-Overholt. Methodological quality was assessed using the Checklist for Analytical Cross-Sectional Studies. Data analysis and synthesis were carried out in a qualitative and descriptive manner, respectively.

RESULTS

the factors associated with workaholism were burnout, stress, anxiety, depression, sleep-related problems, low ability to concentrate and negative incidents at work, which affected the mental health of nurses.

CONCLUSION

the synthesis revealed that workaholism was related to perceived stress at work, emotional exhaustion, depersonalization and anxious and depressive symptoms, which resulted in low professional effectiveness and poor sleep quality among workaholic professionals.

Using item response theory to identify key symptoms of insomnia in a sample of university students with probable eating disorders

PURPOSE

Researchers have theorized that interactions between appetitive and circadian disruptions result in increased eating disorder (ED) symptoms and insomnia. However, it is unclear how specific insomnia symptoms present among people with EDs and if the latent structure of insomnia in this population is similar to that of people with insomnia disorder.

METHODS

We conducted a secondary analysis of data collected on ED and insomnia symptoms using a subset of students (N = 547; 79.52% female) with probable EDs at a large Midwestern American university. Item response theory (IRT) for polytomous items was performed to identify item difficulty, discrimination, and information parameters for the Insomnia Severity Index (ISI). IRT parameters were compared to those established in a 2011 study of people diagnosed with insomnia disorder by Morin and colleagues.

RESULTS

Clinically significant insomnia symptoms were common among students with ED pathology and symptom endorsement for each ISI item ranged from 40.77 to 86.65%. ISI items assessing insomnia-related impairment and distress showed better discriminative capacities and had higher item information than items assessing sleep behavior alterations (i.e., difficulties falling asleep, difficulties maintaining sleep, waking too early). Item discrimination was largely similar among the ED sample compared to previous IRT analyses in an insomnia disorder sample.

CONCLUSION

Insomnia symptoms are common among university students with probable EDs and similar to those reported by people with insomnia disorder. When considering insomnia assessment, items assessing sleep behaviors alone are likely inadequate to provide information about insomnia severity among people with EDs.

LEVEL V

Evidence obtained from a cross-sectional descriptive study.

Psychiatric Characteristics, Symptoms of Insomnia and Depression, Emotion Regulation, and Social Activity among Swiss Medical Students

Background: Almost by default, young adult students are at increased risk of suffering from mental health issues, and this holds particularly true for medical students. Indeed, compared to the general population and non-medical students, medical students report higher scores for symptoms of depression. For Swiss medical students, research on the associations between psychiatric characteristics and symptoms of depression and insomnia, including cognitive-emotional processes and social activity, has been lacking so far. Given this, the aims of the present study were to relate self-declared psychiatric characteristics to symptoms of depression, insomnia, emotion regulation, and social activity. Methods: A total of 575 medical students (mean age: 22.4 years; 68.9% females) completed an online survey covering sociodemographic information (age and gender), study context (year of study), self-declared psychiatric characteristics and symptoms of depression, insomnia, emotion regulation (cognitive reappraisal vs. emotion suppression), and social activity. Data on insomnia sum scores and categories of historical samples (862 non-medical students and 533 police and emergency response service officers) were used for comparison. Results: Of the 575 participants, 190 participants (33%) self-declared psychiatric issues, such as major depressive disorder; anxiety disorders, including PTSD and adjustment disorders; eating disorders; ADHD; or a combination of such psychiatric issues. Self-reporting a psychiatric issue was related to higher symptoms of depression and insomnia and lower symptoms of social activity and cognitive reappraisal (always with significant p-values and medium effect sizes). Compared to historical data for non-medical students and police and emergency response service officers, medical students reported higher insomnia scores. In a regression model, current self-declared psychiatric issues, female gender, higher scores for insomnia, and lower scores for social activity were associated with higher scores for depression. Conclusions: Among a sample of Swiss medical students, the occurrence of self-declared psychiatric issues was associated with higher scores for depression and insomnia and lower cognitive reappraisal and social activity. Further, insomnia scores and insomnia categories were higher when compared to non-medical students and to police and emergency response service officers. The data suggest that medical schools might introduce specifically tailored intervention and support programs to mitigate medical students' mental health issues. This holds particularly true for insomnia, as standardized and online-delivered treatment programs for insomnia (eCBTi) are available.

Perceived Stress, but Not Rumination, Mediates the Relationship Between Trait Mindfulness and Sleep Quality in Young Adults

Objective

Poor sleep among young adults is prevalent, yet the mediating variables are largely understudied, and there is limited relevant work utilizing objective sleep measures. The present study investigated the mediating effects of perceived stress and rumination in the relationship between trait mindfulness and subjective and objective sleep quality in young adults.

Methods

A total of 170 healthy adults (aged 18-37, M = 20.8, SD = 2.9) self-reported on trait mindfulness, perceived stress, and rumination. The primary (N = 140) and secondary (N = 30) samples both completed the Pittsburgh Sleep Quality Index (PSQI) to assess subjective sleep quality. The secondary sample (N = 30) additionally provided sleep diaries, as well as wrist-worn actigraphy data for assessing objective sleep quality. A mediation analysis was conducted to assess the effect of trait mindfulness on sleep quality with perceived stress and rumination as mediators.

Results

Trait mindfulness was positively associated with better subjective sleep quality; this was fully mediated by perceived stress, b = -0.08, 95% CI [-.12, -0.06]. Rumination was negatively associated with subjective sleep quality but did not mediate the relationship between trait mindfulness and sleep quality, b = -0.01, 95% CI [-.03, 0.02]. Only trait mindfulness was correlated with diary-based sleep ratings, and none of the measures were associated with actigraphy-based sleep quality.

Conclusion

This study indicates that perceived stress is an important mediator in the relationship between trait mindfulness and subjective sleep quality among young adults, rather than rumination. These findings have implications for mindfulness-based therapeutic approaches to address the high prevalence of sleep disorders among young adults, adding mechanistic detail to the literature.

Sleep-specific repetitive negative thinking processes and prenatal insomnia symptoms: A naturalistic follow-up study from mid- to late-pregnancy

Insomnia symptoms are highly prevalent during pregnancy; therefore, identifying modifiable risk markers is important for risk prediction and early intervention. This study aimed to examine the role of sleep-specific rumination and sleep-specific worry in prenatal insomnia symptoms. A total of 859 married pregnant women without history of psychiatric illnesses (mean [standard deviation] age, 30.15 [3.86] years; 593 [69.0%] with a bachelor's degree or above) were enrolled from the obstetrical outpatient departments of two tertiary comprehensive hospitals in Shandong, China, who completed assessments of sleep-specific rumination, sleep-specific worry, and insomnia symptoms at baseline (mid-pregnancy) and follow-up (late-pregnancy). Measures included Daytime Insomnia Symptom Response Scale, Anxiety and Preoccupation about Sleep Questionnaire, and Insomnia Severity Index. Our results showed that after controlling for covariates, both sleep-specific rumination and sleep-specific worry showed significant concurrent and prospective associations with insomnia symptoms, and the increases in scores of sleep-specific rumination and sleep-specific worry over time were significantly associated with the increased likelihood of insomnia symptoms at follow-up. Moreover, the increases in sleep-specific rumination and sleep-specific worry over time were significantly associated with the increased likelihood of reporting newly developed insomnia symptoms rather than persistent normal sleep. However, the changes in sleep-specific rumination and sleep-specific worry were not significantly associated with the likelihood of reporting persistent or remitted insomnia symptoms rather than persistent normal sleep. In conclusion, sleep-specific rumination and sleep-specific worry were significantly associated with concurrent or subsequent insomnia symptoms; thus, they may be promising cognitive risk markers and intervention targets.

Conceptual overlap of negative thought processes in insomnia: A focus on catastrophizing, worry, and rumination in a student sample

OBJECTIVES

The association and overlap between different forms of negative thought processes in insomnia is largely unknown. The purpose of the current investigation was to examine conceptual overlap between three insomnia-specific negative thought processes; catastrophizing, worry, and rumination, identify the underlying factors, and explore their associations with insomnia symptoms.

METHODS

A total of 360 students completed three insomnia-related negative thought process scales (Catastrophic Thoughts about Insomnia Scale, Anxiety and Preoccupation about Sleep Questionnaire, Daytime Insomnia Symptom Response Scale) and two insomnia symptoms measures (the Insomnia Severity Index and Sleep Condition Indicator).

RESULTS

The three scales and their subscales displayed acceptable reliabilities. Further, confirmatory factor analysis was supportive of the notion of catastrophizing, worry, and rumination measures as distinct. The catastrophizing and worry constructs were significantly associated with insomnia symptoms, but the rumination factor was not.

CONCLUSIONS

The findings indicate that catastrophizing, worry, and rumination might be viewed as distinct constructs. Although more research is warranted on the topic of conceptual overlap, the current results might have implications for the development of models of insomnia, clinical research, and practice.

Daytime sleepiness in insomnia: Are we focusing on what truly matters?

Insomnia, the most prevalent sleep disorder, is commonly associated with other mental and somatic disorders, making it a significant health concern. It is characterized by nighttime symptoms and daytime dysfunction, with sleepiness being a potential criterion for the latter. Sleepiness is a normal physiological state that is typically experienced near usual bedtime, in normal circumstances. In insomnia, it seems somewhat logical the idea that there is significant daytime sleepiness. However, the topic has been the subject of various discussions in sleep medicine, with studies yielding contradictory and inconsistent results. In this article, we aim to critically examine daytime sleepiness in individuals with insomnia disorder and propose an alternative approach to addressing it, both in clinical practice and research settings. It is crucial to further investigate the role of daytime sleepiness in insomnia, particularly by focusing on sleepiness perception as a more relevant dimension to explore in majority of patients. It is plausible that certain insomnia phenotypes are objectively sleepy during the day, but more studies are necessary, particularly with well-defined clinical samples. The implications of assessing sleepiness perception in insomnia for clinical practice are discussed, and new avenues for research are suggested.

Anxiolytic impact of cognitive behavioural therapy for insomnia in patients with co-morbid insomnia and generalized anxiety disorder

BACKGROUND

Cognitive behavioural therapy for insomnia (CBT-I) is an effective treatment for chronic insomnia that also improves non-sleep symptoms, such as mood and anxiety. Identifying sleep-specific variables that predict anxiety change after CBT-I treatment may support alternative strategies when people with generalized anxiety disorder (GAD) do not improve from standard GAD treatment.

AIMS

To investigate CBT-I on changes in anxiety and evaluate whether changes in sleep-specific variables predict anxiety outcomes.

METHODS

Seventy-two participants presenting with insomnia and GAD (GAD-I) completed four sessions of CBT-I. Participants completed daily diaries and self-report measures at baseline and post-treatment.

RESULTS

CBT-I in a co-morbid GAD-I sample was associated with medium reductions in anxiety, and large reductions in insomnia severity. Subjective insomnia severity and tendencies to ruminate in response to fatigue predicted post-treatment anxiety change, in addition to younger age and lower baseline anxiety.

CONCLUSIONS

The findings suggest that younger GAD-I participants with moderate anxiety symptoms may benefit most from the anxiety-relieving impact of CBT-I. Reducing perceived insomnia severity and the tendency to ruminate in response to fatigue may support reductions in anxiety in those with GAD-I.

A phenomenological inquiry into the costs and consequences of insomnia for veterans with serious mental illness

Many individuals with serious mental illness (i.e. schizophrenia spectrum, bipolar or major depressive disorders, with serious functional impairments) have insomnia symptoms. Insomnia is a common reason for mental health referrals in the Veterans Health Administration. The primary aim of this study was to explore the costs (what participants lose or what trade-offs they make due to insomnia) and consequences (how insomnia impacts functioning) of insomnia for veterans with serious mental illness. Semi-structured interviews of 20 veterans with insomnia and serious mental illness were collected as data using an inductive phenomenological approach. Two main themes were identified: Sleep Affects Mental Health and Functioning; and Compromising to Cope. Results illuminate pathways by which sleep effort destabilizes functional recovery, and illustrate how sleep has multiplicative positive impacts on functioning and mood. Researchers and clinicians alike must explore supporting people with serious mental illness in replacing sleep effort with the recovery of meaningful identity-driven, values-based experiences formerly conceded due to serious mental illness, insomnia or both.

Promoting sleep health during pregnancy for enhancing women's health: a longitudinal randomized controlled trial combining biological, physiological and psychological measures, Maternal Outcome after THERapy for Sleep (MOTHERS)

BACKGROUND

Sleep is vital for maintaining individuals' physical and mental health and is particularly challenged during pregnancy. More than 70% of women during the gestational period report insomnia symptoms. Sleep dysfunction in the peripartum increases the risk for a cascade of negative health outcomes during late pregnancy, birth, and postpartum. While psychological interventions are considered the first line treatment for sleep difficulties, they are still scarcely offered during pregnancy and there is a lack of longitudinal research combining psychological and physiological indices.

METHODS

The present protocol outlines a randomized controlled trial aimed at testing the long-term effectiveness of an automatized digitalized psychoeducational intervention for insomnia for expectant mothers complaining insomnia symptoms without comorbidity. Outcomes include physiological, hormonal, and subjective indices of maternal psychopathology, stress, and emotional processes, and sleep and wellbeing of the family system. The trial is part of a longitudinal study evaluating expectant mothers from early pregnancy (within the 15th gestational week) to 6-months postpartum through 6 observational phases: baseline (BSL), 6- and 12-weeks from BSL (FU1-FU2), 2-to-4 weeks after delivery (FU3), and 3- and 6-months after delivery (FU4-5). We plan to recruit 38 women without sleep difficulties (Group A) and 76 women with sleep difficulties (Group B). Group B will be randomly assigned to digital psychological control intervention (B1) or experimental psychoeducational intervention targeting insomnia (B2). At 3 time points, an ecological-momentary-assessment (EMA) design will be used to collect data on sleep and emotions (diaries), sleep-wake parameters (actigraphy) and stress reactivity (salivary cortisol). We will also test the DNA methylation of genes involved in the stress response as biomarkers of prenatal poor sleep. Information on partner's insomnia symptoms and new-borns' sleep will be collected at each stage.

DISCUSSION

The proposed protocol aims at testing an easily accessible evidence-based psychoeducational intervention for expectant mothers to help them improving sleep, health, and wellbeing in the peripartum. The results could improve the understanding and management of sleep difficulties and peripartum depression.

TRIAL REGISTRATION

The study protocol has been registered on 22 April 2024 with ClinicalTrials.gov Protocol Registration and Results System (PRS), ID: NCT06379074.

PROTOCOL VERSION

April 23, 2024.

Sleep Health and Anxiety Symptoms in Midlife Women: The Study of Women's Health Across the Nation (SWAN)

Purpose

To investigate the associations between anxiety symptoms in midlife women and sleep features later in life, the aim is to test the hypothesis that poor sleep, as measured by each of six individual dimensions (4 objective actigraphy measures, 2 self-reports) of sleep health, is associated with higher levels of anxiety symptoms in midlife women.

Participants and Methods

The participants in this longitudinal analysis included women from the SWAN Sleep I Study, a subcohort of the community-dwelling midlife women participating in the core Study of Women's Health Across the Nation (SWAN), which was initiated in 1996. Of the 370 participants enrolled in the Sleep Study, 270 were included in the analytic sample, and 100 who did not meet the inclusion criteria were excluded. Baseline measures of six dimensions of multidimensional sleep health (actigraphy measures: efficiency, duration, mid-sleep timing, regularity; self-report measures: alertness, satisfaction) were obtained between 2003 and 2005, corresponding to SWAN core annual/biennial assessments 5-8. Associations of each dimension with self-reported anxiety symptoms (Generalized Anxiety Disorder - 7-item scale; GAD-7), collected during visits 12 (2009-2011), 13 (2011-2013), and 15 (2015-2017), were examined using mixed models. The GAD-7 outcome was measured both continuously and as a categorical variable due to its skewed distribution.

Results

No statistically significant associations were found between any of the six baseline sleep health dimensions and the GAD-7 score after adjustment for covariates.

Conclusion

The reasons for the lack of support for our hypothesis, despite previous evidence supporting an association between sleep and anxiety, are unclear. There is considerable overlap between anxiety and sleep symptoms, which may complicate the interpretation of our the findings. Thus, the failure to identify associations is likely multifactorial, and more studies with shorter follow-up intervals are warranted to better understand these relationships.

An exploration into the relationship between insomnia and repetitive negative thinking among cancer survivors

OBJECTIVE

Insomnia and repetitive negative thinking (RNT) are both prevalent among cancer survivors, yet little work has investigated their interrelationship. To explore the hypothesis that RNT and insomnia are related, we conducted secondary analyses on data from a pilot clinical trial of cognitive behavioral therapy for insomnia (CBT-I) for cancer survivors.

METHODS

This study analyzed survey data from 40 cancer survivors with insomnia who participated in a pilot randomized trial of CBT-I. Correlations and linear regression models were used to determine associations between aspects of RNT and related constructs (fear of cancer recurrence [FCR], cancer-specific rumination, worry, and intolerance of uncertainty) and sleep (insomnia and sleep quality), while accounting for psychiatric symptoms such as anxiety and depression. Treatment-related change in RNT was examined using a series of linear mixed models.

RESULTS

Evidence for an association between RNT and insomnia among cancer survivors emerged. Higher levels of FCR and cancer-related rumination were correlated with more severe insomnia symptoms and worse sleep quality. Notably, FCR levels predicted insomnia, even after controlling for anxiety and depression. Results identified potential benefits and limitations of CBT-I in addressing RNT that should be examined more thoroughly in future research.

CONCLUSIONS

RNT is a potential target to consider in insomnia treatment for cancer survivors.

Sleep-related attentional bias in insomnia: The mediating role of arousal

BACKGROUND AND OBJECTIVES

Characterize the nature of attentional biases toward nocturnal and diurnal sleep-related stimuli in individuals with insomnia disorder. We investigated the contributing role of sleep-related attentional biases in insomnia severity and whether their effects on insomnia severity were mediated by arousal and valence levels of the presented stimuli.

METHODS

Sixty-four individuals with insomnia disorder and 70 controls completed two Posner spatial cueing tasks including both nocturnal (alarm clocks) and diurnal (fatigue) pictorial stimuli associated with neutral cues. Arousal and valence of the sleep-related stimuli were assessed using a 5-point Likert type scale.

RESULTS

Attention biases characterized by difficulty disengaging from and increased avoidance for daytime fatigue, and by difficulty disengaging from alarm clocks were observed in individuals with insomnia disorder compared to controls. On the whole sample, difficulty to disengage from diurnal and nocturnal sleep-related stimuli were related mostly to higher arousal rating of sleep-related stimuli and insomnia severity. Higher arousal rating for sleep-related stimuli mediates the relationship between difficulty disengaging and insomnia severity.

LIMITATIONS

The cross-sectional nature of the study.

CONCLUSIONS

We provide first initial evidence for an attentional bias characterized by on one side, avoidance for diurnal sleep-related stimuli and on other side, disengagement for both diurnal and nocturnal sleep-related stimuli in patients with insomnia. Disengagement difficulties for both diurnal and nocturnal sleep-related stimuli indirectly affected insomnia severity through arousal elicited by these stimuli. It appears important to develop and apply attentional bias modification training therapeutic interventions that can effectively reduce sleep-related arousal and attentional biases.

Cognitive Biases and Insomnia Symptoms in People With and Without Chronic Pain

Chronic pain and insomnia symptoms are highly comorbid; however, the psychological mechanisms driving this comorbidity are not well understood. The aim of the present study was to assess whether 2 cognitive biases that occur separately in chronic pain and insomnia, that is, interpretation bias and attentional bias, are heightened in people with comorbid chronic pain and elevated insomnia symptoms. A final sample of N = 109 people with chronic pain and N = 79 people without pain who varied in insomnia symptoms were recruited through Prolific Academic to complete this cross-sectional study. Participants completed measures of sleep and pain-related interpretation bias (ambiguous sentences task) and attentional bias (dot-probe task), as well as questionnaires assessing insomnia symptoms, pain symptoms, and general psychological symptoms. We found an interaction between pain status and insomnia symptoms for sleep-related interpretation bias. That is, people with chronic pain showed greater sleep-related interpretation bias than those without pain, but only when insomnia symptoms were also elevated. This interaction did not extend to pain interpretation bias or attentional bias, although we did find an elevated pain interpretation bias in people with chronic pain compared to pain-free individuals. We also found that both pain and sleep-related interpretation bias were associated with depression symptoms, suggesting that interpretation bias could potentially drive a trimorbidity of chronic pain, insomnia, and depression. Taken together, these findings suggest promise for the role of interpretation bias in the mutual maintenance of chronic pain and insomnia symptoms and the importance of also considering depression. PERSPECTIVE: This article presents data on the cognitive biases that are present in chronic pain, and that are associated with increased insomnia symptoms. Identifying such cognitive biases could help in explaining the high comorbidity between chronic pain and insomnia, leading to more effective and targeted treatments.

Comorbid Insomnia and Sleep Apnea: Challenges and Treatments

Insomnia and obstructive sleep apnea (OSA) are 2 of the most prevalent sleep disorders and frequently co-occur. Therapy can be challenging as treatment of 1 disease may worsen the other. Cognitive behavioral therapy for insomnia is the first-line treatment for insomnia and has been shown to improve compliance with positive airway pressure therapy. Other alternatives to OSA treatment may have higher acceptance in those with comorbid insomnia and sleep apnea (COMISA), such as mandibular advancement devices or emerging pharmacotherapies. Surgery, particularly hypoglossal nerve stimulation, appears to be well tolerated and may improve insomnia in those with COMISA. Otolaryngologists must be cognizant of the common presentation of COMISA in patients seeking surgical treatment and utilize a multidisciplinary approach to the treatment of these complex patients.

Chronic insomnia, REM sleep instability and emotional dysregulation: A pathway to anxiety and depression?

The world-wide prevalence of insomnia disorder reaches up to 10% of the adult population. Women are more often afflicted than men, and insomnia disorder is a risk factor for somatic and mental illness, especially depression and anxiety disorders. Persistent hyperarousals at the cognitive, emotional, cortical and/or physiological levels are central to most theories regarding the pathophysiology of insomnia. Of the defining features of insomnia disorder, the discrepancy between minor objective polysomnographic alterations of sleep continuity and substantive subjective impairment in insomnia disorder remains enigmatic. Microstructural alterations, especially in rapid eye movement sleep ("rapid eye movement sleep instability"), might explain this mismatch between subjective and objective findings. As rapid eye movement sleep represents the most highly aroused brain state during sleep, it might be particularly prone to fragmentation in individuals with persistent hyperarousal. In consequence, mentation during rapid eye movement sleep may be toned more as conscious-like wake experience, reflecting pre-sleep concerns. It is suggested that this instability of rapid eye movement sleep is involved in the mismatch between subjective and objective measures of sleep in insomnia disorder. Furthermore, as rapid eye movement sleep has been linked in previous works to emotional processing, rapid eye movement sleep instability could play a central role in the close association between insomnia and depressive and anxiety disorders.

Association Between Sleep Quality and Deep Learning-Based Sleep Onset Latency Distribution Using an Electroencephalogram

To evaluate sleep quality, it is necessary to monitor overnight sleep duration. However, sleep monitoring typically requires more than 7 hours, which can be inefficient in termxs of data size and analysis. Therefore, we proposed to develop a deep learning-based model using a 30 sec sleep electroencephalogram (EEG) early in the sleep cycle to predict sleep onset latency (SOL) distribution and explore associations with sleep quality (SQ). We propose a deep learning model composed of a structure that decomposes and restores the signal in epoch units and a structure that predicts the SOL distribution. We used the Sleep Heart Health Study public dataset, which includes a large number of study subjects, to estimate and evaluate the proposed model. The proposed model estimated the SOL distribution and divided it into four clusters. The advantage of the proposed model is that it shows the process of falling asleep for individual participants as a probability graph over time. Furthermore, we compared the baseline of good SQ and SOL and showed that less than 10 minutes SOL correlated better with good SQ. Moreover, it was the most suitable sleep feature that could be predicted using early EEG, compared with the total sleep time, sleep efficiency, and actual sleep time. Our study showed the feasibility of estimating SOL distribution using deep learning with an early EEG and showed that SOL distribution within 10 minutes was associated with good SQ.

Relationship between the presence of meaning in life and sleep quality: A moderated chain-mediation model

Sleep is a vital component of health; however, sleep issues are particularly prominent among college students. Identifying protective factors for sleep among college students is of paramount importance. To investigate the mechanisms behind the association between the presence of meaning in life (PML) and sleep quality, we conducted two questionnaire surveys (separated by an interval of 6 months) with 5660 college students to collect longitudinal data. The results show that PML predicted sleep quality and that this relationship was influenced by the mediating effect of depression and the chain mediating effect of coping style and depression; further, the search for meaning in life played a moderating role in the chain mediation model. This study offers new theoretical perspectives on the protective factors of sleep quality and provides empirical insights useful for improving sleep health among college students.

Psychological inflexibility as a predictor associated with insomnia

Psychological flexibility has recently attracted the attention of researchers in the field of sleep disorders; therefore, in the study, psychological flexibility was evaluated as a predictor or factor related to the presence/severity of insomnia. We included 2218 individuals selected from the randomized-control trial for behavioural therapy for insomnia and cross-sectional studies, including 1797 individuals with insomnia and 421 controls without insomnia. All participants completed the DSM-5-based insomnia diagnosis interview, Insomnia Severity Index, Hospital Anxiety and Depression Scale, and Acceptance Action Questionnaire-II. Linear regression and multinomial logistic regression models were used. Sex, education, occupation, marital status, anxiety, depression and psychological inflexibility were possible predictors or factors associated with the severity of insomnia. Multivariate linear regression analysis demonstrated that sex (𝛽 = 0.88; t = 2.80; p = 0.005), depression (𝛽  = 0.41; t = 10.7; p < 0.001), anxiety (𝛽  = 0.58; t = 14.1; p < 0.001) and psychological inflexibility (𝛽  = 0.09; t = 5.07; p < 0.001) were predictors of insomnia. The results of the multinomial logistic regression demonstrate that, in comparison to the absence of insomnia, insomnia at all levels (mild, moderate and severe) was associated with sex, anxiety and depression. Psychological inflexibility was only associated with severe insomnia (odds ratio = 1.04). These findings are important from a public health perspective because behavioural strategies designed to treat insomnia with a focus on psychological flexibility are low-cost and may help improve sleep quality in adults with insomnia, which also influences mental health.

Prediction of insomnia severity based on early maladaptive schemas: a logistic regression analysis

BACKGROUND

In spite of the major role of early maladaptive schemas in vulnerability to various psychological disorders, studies about the relationship between early maladaptive schemas and insomnia disorder are scarce. Hence, the aim of the current study was to explore the contribution of early maladaptive schemas in insomnia severity by comparing a sample of patients with chronic insomnia and good sleepers.

METHODS

Patients with chronic insomnia and good sleepers were evaluated using Young Schema Questionnaire-Short Form (YSQ-SF), Depression Anxiety and Stress Scale (DASS-21), and Insomnia Severity Index (ISI).

RESULTS

The study enrolled 117 patients with chronic insomnia and 76 good sleepers. All early maladaptive schemas (EMSs) except for enmeshment showed significant correlations with insomnia severity. After controlling for depression/anxiety symptoms, logistic regression analysis showed that the EMSs including emotional deprivation, vulnerability to harm, and subjugation schemas were significantly associated with insomnia severity.

CONCLUSIONS

These preliminary findings suggest that EMSs may constitute a vulnerability factor for developing insomnia. Early maladaptive schemas may require attention in the existing treatments of insomnia.

Contribution of dysfunctional sleep-related cognitions on insomnia severity: a network perspective

STUDY OBJECTIVES

Various models of insomnia stress the role of cognitive components, such as dysfunctional sleep-related beliefs, in maintenance and exacerbation of insomnia. This study aimed to use network analysis to identify the particular beliefs that are central and have strong associations with insomnia severity. In addition, we aimed to use a relative importance network to map out predictive pathways between types of dysfunctional beliefs and insomnia severity.

METHODS

This study was a retrospective study, with data collected from 219 patients with insomnia. Patients' responses to the Dysfunctional Beliefs about Sleep Scale-16 (DBAS-16) and Insomnia Severity Index (ISI) were collected. All network analyses were performed using R Studio to produce 3 networks: (1) DBAS-16 network, (2) DBAS-16 and ISI network, and (3) relative importance network containing DBAS-16 subscales and ISI.

RESULTS

Beliefs reflecting overestimation of negative consequences of sleep (eg, "insomnia is ruining life"), loss of ability (eg, "worry about losing abilities to sleep"), and unpredictability (eg, "can't predict sleep quality") were identified as most central and strongly associated with insomnia severity. Worry/helplessness about insomnia had the largest predictive value on insomnia severity, and also acted as a mediator between other subscales and insomnia severity.

CONCLUSIONS

The results of our study suggest that overestimation of negative consequences, loss of ability, and unpredictability are key beliefs that exacerbate and maintain insomnia, thus supporting existing cognitive models of insomnia.

CITATION

Cha EJ, Hong S, Kim S, Chung S, Jeon HJ. Contribution of dysfunctional sleep-related cognitions on insomnia severity: a network perspective. J Clin Sleep Med. 2024;20(5):743-751.

Dyadic Investigation of Posttraumatic Stress Symptoms and Daily Sleep Health in Patients With Cancer and Their Caregivers

OBJECTIVE

Cancer can be a traumatic experience affecting multidimensional aspects of sleep among patients and caregivers. This study examined the differential associations of cancer-related posttraumatic stress symptoms (PTSS) with various sleep markers in this population.

METHODS

Patients newly diagnosed with colorectal cancer ( n = 138, mean age = 56.93 years, 31.88% female, 60.14% Hispanic, 6.53 months after diagnosis) and their sleep-partner caregivers ( n = 138, mean age = 55.32 years, 68.12% female, 57.97% Hispanic) completed questionnaires assessing the four PTSS clusters (intrusion, avoidance, alterations in arousal and reactivity, negative alterations in cognitions and mood). Participants also completed daily sleep diaries for 14 consecutive days, from which sleep onset latency (SOL), wake after sleep onset (WASO), and sleep duration were derived.

RESULTS

Actor-partner interdependence model revealed that caregivers' greater alterations in arousal and reactivity were associated with their own longer SOL ( b = 15.59, p < .001) and their patients' longer sleep duration ( b = 0.61, p = .014), whereas patients' arousal and reactivity were associated with their caregivers' shorter SOL ( b = -8.47, p = .050). Patients' and caregivers' greater negative alterations in cognitions and mood were associated with patients' longer SOL ( b = 9.15, p = .014) and shorter sleep duration ( b = -0.41, p = .050), respectively. Caregivers' greater intrusion was related to their own shorter SOL ( b = -10.14, p = .004).

CONCLUSIONS

The four PTSS clusters, particularly arousal and reactivity and negative cognitions and mood, have distinct associations with sleep markers individually and dyadically in patients and caregivers affected by cancer. Investigations of psychosocial and biobehavioral pathways underlying these relations are warranted. Tailored trauma treatments and sleep interventions may improve the well-being of this population.

Are sleep-related beliefs and behaviours dysfunctional in people with insomnia after acquired brain injury? A cross-sectional study

Inappropriate sleep-related beliefs and behaviours are considered key maladaptive mechanisms in the development and maintenance of insomnia in the otherwise healthy population. The aim of this study was to evaluate critically the role of sleep-related beliefs and behaviours in insomnia after acquired brain injury. Cross-sectional data of 51 outpatients with insomnia disorder and acquired brain injury were used to evaluate associations of the insomnia severity index with the dysfunctional beliefs and attitudes about sleep scale and sleep-related behaviours questionnaire. Seven (44%) of the dysfunctional beliefs and attitudes about sleep scale items and 10 (31%) of the sleep-related behaviours questionnaire items correlated significantly with insomnia severity. Ten experts were consulted on whether they considered the questionnaire items maladaptive or accurately reflecting coping with conditions experienced by people with acquired brain injury. Although multiple linear regression showed that the total scores of the questionnaires explained a significant part of interindividual differences in insomnia severity (R2 = 0.27, F(2,48) = 8.72, p < 0.01), the experts unanimously rated only four (25%) of the dysfunctional beliefs and attitudes about sleep scale items as dysfunctional beliefs and three (9%) of the sleep-related behaviours questionnaire items as safety behaviours. In people with brain injury, sleep related beliefs and behaviours may also play a role in insomnia, especially a diminished perception of control and worry about sleep. However, more than half of the questionnaire items on sleep-related beliefs and behaviours may not be considered inappropriate and maladaptive for the acquired brain injury population, and may reflect adequate observations and efforts in coping with consequences of the brain damage.

Negative life events and sleep disturbance among adolescents: Intolerance of uncertainty as mediator and moderator

BACKGROUND

While negative life events (NLEs) have been linked to an increased risk of sleep disturbance among adolescents, the mechanisms of this impact still lack further examination. The current study aimed to explore whether intolerance of uncertainty (IU), a dispositional transdiagnostic vulnerability factor for psychopathology, could act as a mediator and/or moderator in the link from NLEs to sleep disturbance.

METHODS

A longitudinal nested subsample of 54,240 Chinese adolescents (aged 9-19) were surveyed at baseline (Timepoint 1) and six months later (Timepoint 2). They completed questionnaires to assess their IU, NLEs, sleep disturbance and sociodemographic characteristics. Mediation and moderation analyses were conducted to test our hypotheses.

RESULTS

Upon adjusting for covariates, IU was found to mediate the relationship between NLEs and residual changes in sleep disturbance over a six-month period, with the mediation effect accounting for 31.8%. Additionally, the moderating role of IU in this relationship was also identified, suggesting that a high level of IU exacerbated the effect of NLEs on sleep disturbance.

CONCLUSIONS

In conclusion, our findings shed light on the dual roles of IU in the link from NLEs to sleep disturbance, holding significant practical implications for preventing and intervening in sleep disturbance among adolescents. To mitigate the risk of sleep disturbance among adolescents experiencing NLEs, timely assessments of IU and tailored interventions to enhance uncertainty tolerance are necessary.

The effectiveness of stimulus control in cognitive behavioural therapy for insomnia in adults: A systematic review and network meta-analysis

Stimulus control is part of the widely used cognitive behavioural therapy for insomnia. However, there is a lack of knowledge about its mechanisms of action and effectiveness when used alone. This systematic review with network meta-analysis aimed to evaluate stimulus control efficacy when used alone compared with cognitive behavioural therapy for insomnia or its components. The review also documented stimulus control mechanisms of action proposed by the authors. A search was conducted in several bibliographic databases (MEDLINE, PsycINFO, Embase, CINAHL, Psychology Behavioural Sciences Collection, Web of Science, and Cochrane Library) and in two registers from 1972 to June 2022. Randomised studies with adult participants presenting a diagnosis of insomnia and including at least one stimulus control instruction in a treatment group were included. Risk of bias was assessed with the Quality Assessment of Controlled Intervention Studies. Twenty-three studies were included and three network meta-analyses were conducted. The quality of included studies was generally poor. Results indicate that stimulus control is an effective intervention to improve insomnia compared with control conditions. Not all stimulus control instructions seem essential, especially those known to recondition the bedroom for sleep. The review challenges the classical conditioning hypothesis. Results should be interpreted cautiously given the small number of studies included, bias risk, and inconsistencies in the network meta-analysis. Rigorous research is needed in evaluating stimulus control efficacy and mechanisms.

Association Between Sleep-related Cognitions, Sleep-related Behaviors, and Insomnia in Patients with Anxiety and Depression: A Cross-sectional Study

Background

The cognitive model of insomnia states that worry about sleep contributes to poor sleep quality. Besides worry, beliefs about sleep and maladaptive safety behaviors also affect sleep quality. We aimed to find the association among the presence of insomnia, sleep-related cognitions, and behaviors among patients diagnosed with anxiety or depression.

Methodology

The present cross-sectional comparison study included patients with anxiety spectrum or depressive disorders as per the Diagnostic and Statistical Manual for Mental Disorders-fifth edition and healthy controls. Mood status, insomnia severity, sleep quality, dysfunctional beliefs about sleep, maladaptive safety behaviors, and pre-sleep arousal were evaluated using Hamilton Anxiety Scale (HAM-A), Montgomery Åsberg Depression Rating Scale (MADRS), Insomnia Severity Index, Pittsburgh Sleep Quality Index, Dysfunctional Beliefs and Attitudes Sleep Scale (DBAS), Sleep-related Behavior Questionnaire (SRBQ), and Pre-sleep Arousal Scale (PSAS), respectively. A p value ≤.05 was considered statistically significant.

Results

Both patients (n = 80) and controls (n = 80) were similar in sociodemographic profile, though the sample was predominantly female. Comparison between patients with insomnia (n = 60), patients without insomnia (n = 20), and healthy controls (n = 80) showed that HAM-A and MADRS, DBAS, SRBQ, and PSAS scores were higher in patients with insomnia compared to their counterparts. DBAS and SRBQ scores positively correlated with increasing severity of insomnia. Dysfunctional beliefs regarding sleep (OR: 1.05; 95% CI = 1.00-1.09) and maladaptive behaviors related to sleep (OR: 1.02; 95% CI = 1.00-1.05) predicted insomnia in patients with depression or anxiety.

Conclusion

Insomnia in anxiety or depression is associated with illness severity, dysfunctional beliefs regarding sleep, and sleep-related maladaptive behaviors. Maladaptive cognitions and behaviors can independently influence sleep quality.

The relationships among metacognitive functions, sleep-related thought-control strategies and sleep quality: A mediation analysis

In the context of sleep disturbances, increasing evidence suggests a critical role of sleep-related dysfunctional metacognitive activity, including metacognitive control of intrusive thoughts in the pre-sleep period. Although the relationship between sleep-related thought-control strategies and poor sleep quality is well recognized, the possible contribution of general metacognitive functioning within this relation is still unclear. In this study, we performed a mediation analysis to examine the role of thought-control strategies on the relationship between metacognitive abilities and sleep quality in individuals with different self-reported sleep characteristics. Two-hundred and forty-five individuals participated in the study. Participants completed the Pittsburgh Sleep Quality Index, the Thought Control Questionnaire Insomnia-Revised, and the Metacognition Self-Assessment Scale to evaluate sleep quality, thought-control strategies and metacognitive functions, respectively. The results showed that worry strategy in the pre-sleep period mediates the relationship between metacognitive functions and sleep quality. Particularly, the ability to understand one's mental states and mastery functions could be the two metacognitive domains primarily involved in the dysfunctional metacognitive thought-control activity responsible for reduced sleep quality. The observed effect suggests that inadequate metacognitive functioning is associated with poor sleep quality in healthy subjects via the mediation of dysfunctional worry strategy. These findings suggest the potential relevance of clinical interventions to enhance specific metacognitive abilities, with the aim to promote more functional strategies for managing cognitive and emotional processes during the pre-sleep period.

Relationships between rumination and different types of rapid eye movement sleep in patients with chronic insomnia disorder

BACKGROUND AND OBJECTIVE

Rumination, a common factor of chronic insomnia disorder (CID) caused by cognitive-emotional arousal, is associated with an increased amount of rapid eye movement (REM) sleep. However, the specific subtypes, such as phasic REM and tonic REM, that contribute to the increased REM sleep have not been reported. This study aimed to determine the association between rumination and different REM sleep subtypes in patients with CID.

METHODS

This study enrolled 35 patients with CID and 27 age- and sex-matched healthy controls. The Immersion-Rumination Questionnaire evaluated participants' rumination, and the Insomnia Severity Index was used to assess insomnia severity. Finally, polysomnography was used to monitor objective sleep quality and quantification of different types of REM.

RESULTS

The CID patients had higher rumination scores than the healthy controls. They had a shorter REM sleep duration, less phasic REM, a lower percentage of phasic REM time, and a higher percentage of tonic REM time. Spectral analysis revealed that the patients affected by insomnia had higher β power during REM sleep, higher β and σ power during phasic REM sleep, and higher β, and γ power during tonic REM sleep. Partial correlation analysis showed that rumination in the CID patients correlated negatively with the duration of phasic REM sleep. Additionally, rumination correlated negatively with δ power in REM sleep and positively with β power in REM sleep, tonic REM sleep, phasic REM sleep, N3and N2 sleep in the patients with CID.

CONCLUSION

The CID patients had stronger rumination, reduced total and phasic REM sleep, and the stronger rumination was, the shorter phasic REM was and the higher fast (β) wave power in REM sleep.

The comparison of brief, online mindfulness and relaxation interventions to reduce stress and improve sleep-related outcomes in college students

OBJECTIVE

The current study aimed to examine whether brief online stress reduction exercises supplemented with sleep improvement strategies would reduce stress, arousal, and sleep difficulties in college students who were not required to use the sleep improvement strategies for participation.

PARTICIPANTS

A sample of 114 college student participants were enrolled because they were experiencing stress and/or wanted to improve their sleep.

METHODS

Participants were randomized into an abbreviated progressive muscle relaxation, a mindful breathing, or a self-monitoring control condition for the 4-week intervention. Measures of physical relaxation, mindfulness, perceived stress, pre-sleep arousal, and insomnia symptom severity were collected.

RESULTS

The APMR group improved on five of the six dependent measures and was significantly different than the SM group at posttest, but not different than the MB group.

CONCLUSION

The results suggests promise for brief, online, scaled back stress reduction interventions to reduce stress, arousal, and sleep difficulties in college students.

The Impact of Problematic Smartphone Use on Sleep Quality Among Chinese Young Adults: Investigating Anxiety and Depression as Mediators in a Three-Wave Longitudinal Study

Background

Sleep disorders are a significant health issue that urgently needs to be addressed among undergraduate students, and one of the potential underlying problems could be problematic smartphone use (PSU). This study aimed to clarify the relationship between PSU and poor sleep quality by investigating the independent and serial mediating roles of anxiety and depressive symptoms in a population of university students in Tibet, China.

Methods

A total of 2993 Tibetan college students completed three waves of data surveys, with all participants completing questionnaires on PSU, anxiety, depressive symptoms, and sleep quality (Time 1 (T1) -Time 3 (T3)). Bootstrapped mediation analysis was used to explore the mediating role of anxiety and depressive symptoms in the longitudinal relationship between PSU and sleep quality.

Results

Both direct and indirect effects of PSU on poor sleep quality were found. PSU (T1) can had not only a direct negative influence on poor sleep quality (T3) among young adults (direct effect = 0.021, 95% CI = 0.010-0.033) but also an indirect negative impact via three pathways: the independent mediating effect of anxiety symptoms (T2) (indirect effect 1 = 0.003, 95% CI = 0.001-0.006), the independent mediating effect of depressive symptoms (T2) (indirect effect 2 = 0.004, 95% CI = 0.002-0.006), and the serial mediating effects of anxiety (T2) and depressive symptoms (T2) (indirect effect 3 = 0.008, 95% CI=0.005-0.011).

Conclusion

These findings highlight the role of anxiety and depression symptoms as joint mediating factors in the relationship between PSU and sleep disturbances. Interventions focused on improving sleep that incorporate behavioural measures could benefit from treatment approaches targeting mental disorders.

Exploring relationship of poor sleeping habits with prenatal stress among pregnant women in Pakistan: a cross-sectional study

OBJECTIVE

Pregnancy is a complex phenomenon accompanied by biological, physiological and psychosocial changes for a mother. It is also regarded as a stressful life event where a woman's role, identity and interpersonal relationships are restructured. The present study from Pakistan explores the association of sleep quality and poor sleeping habits with prenatal stress using Pittsburgh Sleep quality Index.

RESULTS

There were a total of 516 women (mean age = 29.82 years), with more than half reporting poor sleep quality. Ethnically, a majority (395, 76.6%) were natives of the Punjab province while rest were non-natives. A high percentage of respondents reported poor subjective sleep quality (22.1%), sleep latency (44.1%), habitual sleep efficiency (27.5%), sleep disturbance (30.1%), use of medications (7.1%) and daytime dysfunction (29.5%). According to logistic regression analysis, respondents with poor sleep quality were 2.24 (95% CI = 1.55-3.22, P < 0.001) times more likely to have high stress levels (P < 0.001).

The natural history of insomnia: evaluating illness severity from acute to chronic insomnia; is the first the worst?

STUDY OBJECTIVES

The 3P and 4P models represent illness severity over the course of insomnia disorder. The 3P model suggests that illness severity is worst during acute onset. The 4P model suggests that illness severity crescendos with chronicity. The present analysis from an archival dataset assesses illness severity with new onset illness (i.e. from good sleep [GS] to acute insomnia [AI] to chronic insomnia [CI]). Illness severity is quantified in terms of total wake time (TWT).

METHODS

GSs (N = 934) were followed up to 1 year with digital sleep diaries, and classified as GS, AI, or CI. Data for CIs were anchored to the first of 14 days with insomnia so that day-to-day TWT was represented prior to and following AI onset. A similar graphic (+/-acute onset) was constructed for number of days per week with insomnia. GS data were temporally matched to CI data. Segmented linear mixed regression models were applied to examine the change in slopes in the AI-to-CI period compared to GS-to-AI period.

RESULTS

Twenty-three individuals transitioned to AI and then CI. Average TWT rose during the first 2 weeks of AI onset (b = 1.8, SE = 0.57, p = 0.001) and was then stable for 3 months (b = -0.02, SE = 0.04, p = 0.53). Average number of affected days was stable from AI to CI (b = 0.0005, SE = 0.002, p = 0.81). That is, while there was week-to-week variability in the number of days affected, no linear trend was evident.

CONCLUSIONS

In our sample of CIs, primarily with middle insomnia, the average severity and number of affected days were worst with the onset of AI (worst is first) and stable thereafter.

Associations between Sleep Disturbances, Personality Traits and Self-Regulation in a Sample of Healthy Adults

Background: Scientific evidence and everyday experience show that sleep disturbances and self-regulation as a proxy of stress reactivity are linked. Particular personality traits such as neuroticism, internalizing and externalizing problems are also associated with sleep disturbances. Here, we combined self-regulation and personality traits and associated these variables with subjective sleep disturbances. Methods: A total of 846 adults (mean age: 33.7 years; 78.7% females) completed questionnaires covering sleep disturbances, self-regulation and personality traits. Results: Higher scores for sleep disturbances were associated with higher scores for externalization, internalization, and instability and with lower scores for stability (all trait variables) and with poorer self-regulation (state variable). The regression model showed that higher scores for externalization and internalization (traits), and lower scores for self-regulation (state) predicted higher scores for sleep disturbance. Next, self-regulation had both a direct effect on sleep disturbance, and an indirect effect via personality traits. Conclusions: Sleep disturbances were related to both state (i.e., self-regulation) and trait (e.g., internalization and instability) dimensions. The current data analysis leapfrogs the state-trait dichotomy discussion and reconciles the state-and-trait approach in the prediction of poor sleep, though self-regulation appeared to have both direct and indirect effects on sleep disturbances.

Interactions between insomnia, sleep duration and emotional processes: An ecological momentary assessment of longitudinal influences combining self-report and physiological measures

Previous studies indicated that further investigation is needed to understand how insomnia disorder interacts with emotional processes. The present study is an ecological momentary assessment evaluating the link between emotional and sleep alterations in patients with insomnia. Physiological (heart rate and heart rate variability) and subjective (sleep and emotions) indices were observed for 5 days in patients with insomnia disorder (n = 97), good sleepers under self-imposed sleep restriction (n = 41), and good sleepers with usual amount of sleep (n = 45). We evaluated differences in emotion regulation strategies and in valence and variability of emotional experiences. Over 5 days, patients with insomnia showed increased sleep and emotional difficulties compared with both control groups. Independent from group allocation, days with more negative emotions were associated with higher sleep alterations. Longer wake episodes at night and higher diurnal heart rate were associated with increased variations in emotion experienced during the day. Only in patients with insomnia, use of adaptive emotion regulation strategies was associated with higher sleep efficiency. Our data showed that alterations in sleep and emotional processes are closely linked. A combination of strategies targeting both sleep and emotional processes appears promising in the prevention and treatment of insomnia disorder.

The role of rumination in the relationship between symptoms of insomnia and depression in adolescents

There is a strong relationship between the symptoms of insomnia and depression, however, little is understood about the factors that mediate this relationship. An understanding of these underlying mechanisms may inform the advancement of existing treatments to optimise reductions in insomnia and depression when they co-occur. This study examined rumination and unhelpful beliefs about sleep as mediators between symptoms of insomnia and depression. It also evaluated the effect of cognitive behavioural therapy for insomnia (CBT-I) on rumination and unhelpful beliefs about sleep, and whether these factors mediated the effect of CBT-I on depressive symptoms. A series of mediation analyses and linear mixed modelling were conducted on data from 264 adolescents (12-16 years) who participated in a two-arm (intervention vs. control) randomised controlled trial of Sleep Ninja®, a CBT-I smartphone app for adolescents. Rumination, but not unhelpful beliefs about sleep, was a significant mediator between symptoms of insomnia and depression at baseline. CBT-I led to reductions in unhelpful beliefs about sleep, but not in rumination. At the between-group level, neither rumination, nor unhelpful beliefs about sleep emerged as mechanisms underlying improvement in depression symptoms, however, rumination mediated within-subject improvements following CBT-I. The findings suggest rumination links symptoms of insomnia and depression and provide preliminary evidence that reductions in depression following CBT-I occurs via improvements in rumination. Targeting rumination may improve current therapeutic approaches.