Neurocognitive performance in insomnia disorder: The impact of hyperarousal and short sleep duration

Sleep disorders and hyperarousal among patients with endometriosis: A case-control survey study

BACKGROUND

Endometriosis has been associated with sleep disorders, and hyperarousal appears to be involved in their pathogenesis; however, the presence of hyperarousal in the endometriosis population was never investigated.

METHODS

We conducted a case-control survey study by sending a questionnaire to all endometriosis patients followed up at our Centers. Controls were recruited among the general population. The questionnaire included demographic information, symptoms and history of endometriosis, the Hyperarousal Scale (H-Scale), the Pittsburgh Sleep Quality Index (PSQI), and the Insomnia Severity Index (ISI).

RESULTS

A total of 847 women completed the questionnaires: 430 (50.8 %) had endometriosis, and 417 (49.2 %) were controls. Endometriosis was associated with higher H-scale score (OR 2.9, 95 % CI 2.4-3.8, p = 0.000), higher PSQI score (OR 4.3, 95 % CI 3.2-5.7, p = 0.000), and higher ISI score (OR 4.6, 95 % CI 3.5-6.1, p = 0.000) in multivariable ordinal logistic regressions analysis. With path analysis, hyperarousal (H-Scale) reported a partial mediating role in the association between endometriosis and sleep disorders. The mediation effect represented 22.3-27.8 % of the entire association between endometriosis and sleep disturbances.

CONCLUSION

Endometriosis patients complaining sleep disorders may benefit by investigating the presence of hyperarousal given cognitive behavioral therapy was reported effective in improving hyperarousal and associated sleep disorders.

Wavelet Entropy Analysis of Electroencephalogram Signals During Wake and Different Sleep Stages in Patients with Insomnia Disorder

Objective

To investigate the changes in the wavelet entropy during wake and different sleep stages in patients with insomnia disorder.

Methods

Sixteen patients with insomnia disorder and sixteen normal controls were enrolled. They underwent scale assessment and two consecutive nights of polysomnography (PSG). Wavelet entropy analysis of electroencephalogram (EEG) signals recorded from all participants in the two groups was performed. The changes in the integral wavelet entropy (En) and individual-scale wavelet entropy (En(a)) during wake and different sleep stages in the two groups were observed, and the differences between the two groups were compared.

Results

The insomnia disorder group exhibited lower En during the wake stage, and higher En during the N3 stage compared with the normal control group (all P < 0.001). In terms of En(a), patients with insomnia disorder exhibited lower En(a) in the β and α frequency bands during the wake stage compared with normal controls (β band, P < 0.01; α band, P < 0.001), whereas they showed higher En(a) in the β and α frequency bands during the N3 stage than normal controls (β band, P < 0.001; α band, P < 0.001).

Conclusion

Wavelet entropy can reflect the changes in the complexity of EEG signals during wake and different sleep stages in patients with insomnia disorder, which provides a new method and insights about understanding of pathophysiological mechanisms of insomnia disorder. Wavelet entropy provides an objective indicator for assessing sleep quality.

Sleep-EEG in comorbid pain and insomnia: implications for the treatment of pain disorders

Introduction

Patients with chronic pain experience a high prevalence of comorbid insomnia, which is associated with functional impairment. Recent advances in sleep electroencephalography (sleep-EEG) may clarify the mechanisms that link sleep and chronic pain. In this clinical update, we outline current advancements in sleep-EEG assessments for pain and provide research recommendations.

Results

Promising preliminary work suggests that sleep-EEG spectral bands, particularly beta, gamma, alpha, and delta power, may create candidate neurophysiological signatures of pain, and macro-architectural parameters (e.g., total sleep time, arousals, and sleep continuity) may facilitate EEG-derived sleep phenotyping and may enable future stratification in the treatment of pain.

Conclusion

Integration of measures obtained through sleep-EEG represent feasible and scalable approaches that could be adopted in the future. We provide research recommendations to progress the field towards a deeper understanding of their utility and potential future applications in clinical practice.

Neural mechanisms of working memory dysfunction in patients with chronic insomnia disorder

OBJECTIVE

This study aimed to investigate the neural mechanisms underlying working memory impairment in patients with chronic insomnia disorder (CID) using event-related potentials (ERP) and resting-state functional connectivity (rsFC) approaches.

METHODS

Participants, including CID patients and healthy controls (HCs), completed clinical scales and underwent electroencephalography (EEG) and functional magnetic resonance imaging (fMRI). EEG analysis compared reaction times, P3 amplitudes, event-related spectral perturbations (ERSP), and inter-trial phase synchronisation (ITPS) between CID patients and HCs. Subsequently, frontal regions (i.e., the Superior Frontal Gyrus [SFG] and Middle Frontal Gyrus [MFG]) corresponding to the EEG were selected as seeds for rsFC analysis. Correlation analyses were conducted to further investigate the relationship between functional connectivity abnormalities in brain regions and clinical symptom severity and P3 amplitude in CID patients.

RESULTS

Compared to HCs, CID patients exhibited slower reaction times across all working memory conditions, with the deficits becoming more pronounced as memory load increased. ERP analysis revealed increased P3 amplitude, theta wave power, and reduced inter-trial synchrony in CID patients. rsFC analysis showed decreased connectivity of SFG-posterior cingulated cortex (PCC), SFG-MFG, and MFG-frontal pole (FP), and increased connectivity of MFG- Middle Temporal Gyrus (MTG)in CID patients. Importantly, a significant correlation was found between the rsFC of SFG-MTG and P3 amplitude during 1-back.

CONCLUSION

This study confirms deficits in working memory capacity in patients with CID, specifically in the neural mechanisms of cognitive processing that vary depending on the level of cognitive load. Alterations in connectivity patterns within and between the frontal and temporal regions may be the neural basis of the cognitive impairment.

Insomnia nosology: a systematic review and critical appraisal of historical diagnostic categories and current phenotypes

Insomnia nosology has significantly evolved since the Diagnostic and Statistical Manual (DSM)-III-R first distinguished between 'primary' and 'secondary' insomnia. Prior International Classification of Sleep Disorders (ICSD) nosology 'split' diagnostic phenotypes to address insomnia's heterogeneity and the DSM nosology 'lumped' them into primary insomnia, while both systems assumed causality for insomnia secondary to health conditions. In this systematic review, we discuss the historical phenotypes in prior insomnia nosology, present findings for currently proposed insomnia phenotypes based on more robust approaches, and critically appraise the most relevant ones. Electronic databases PsychINFO, PubMED, Web of Science, and references of eligible articles, were accessed to find diagnostic manuals, literature on insomnia phenotypes, including systematic reviews or meta-analysis, and assessments of the reliability or validity of insomnia diagnoses, identifying 184 articles. The data show that previous insomnia diagnoses lacked reliability and validity, leading current DSM-5-TR and ICSD-3 nosology to 'lump' phenotypes into a single diagnosis comorbid with health conditions. However, at least two new, robust insomnia phenotyping approaches were identified. One approach is multidimensional-multimethod and provides evidence for self-reported insomnia with objective short versus normal sleep duration linked to clinically relevant outcomes, while the other is multidimensional and provides evidence for two to five clusters (phenotypes) based on self-reported trait, state, and/or life-history data. Some approaches still need replication to better support whether their findings identify true phenotypes or simply different patterns of symptomatology. Regardless, these phenotyping efforts aim at improving insomnia nosology both as a classification system and as a mechanism to guide treatment.

Abnormal functional connectivity in the habenula is associated with subjective hyperarousal state in chronic insomnia disorder

Background

The hyperarousal process model plays a central role in the physiology of chronic insomnia disorder (CID). Recent evidence has demonstrated that the habenula is involved in the arousal and sleep-wake cycle. However, whether the intrinsic habenular functional network contributes to the underlying mechanism of CID and its relationship to the arousal state in CID remains unclear.

Methods

This single-centered study included 34 patients with subjective CID and 22 matched good sleep control (GSC), and underwent a series of neuropsychological tests and resting-state functional magnetic resonance imaging scans. The habenular functional network was assessed using seed-based functional connectivity (FC) analysis. The subjective arousal state was evaluated with the hyperarousal scale (HAS). Alterations in the habenular FC network and their clinical significance in patients with CID were explored.

Results

Compared with the GSC group, the CID group showed decreased habenular FC in the left caudate nucleus and right inferior parietal lobule and increased FC in the right habenula, bilateral calcarine cortex, and posterior cingulate cortex. The decreased FC between the left habenula and caudate nucleus was associated with an increased arousal state in the CID group.

Conclusion

The present results provide evidence for a dysfunctional habenular network in patients with CID. These findings extend our understanding of the neuropathological mechanisms underlying the hyperarousal model in chronic insomnia.

Effects of acupuncture on the brain in primary insomnia: a coordinate-based meta-analysis of fMRI studies

Importance

Primary insomnia (PI) has a high global incidence, and effective treatments with fewer side effects are needed. Acupuncture, a treatment used in traditional Chinese medicine, has become increasingly established as a treatment method for PI and is recognized by many physicians and patients. Some evidence has suggested that acupuncture was associated with improvements in objective sleep parameters and might induce changes in some brain regions. Individual studies with limited sample size and low detection thresholds may lead to false positives, and no systematic review of the effects of acupuncture has been conducted in PI.

Objective

The aim of this systematic review and coordinate-based meta-analysis was to summarize the literature on fMRI evaluation of patients with PI treated with acupuncture.

Design

We performed a methodical and comprehensive search of multiple publication databases (from inception to December 2022): Web of Science, PubMed, ScienceDirect, Embase, Wan Fang, China National Knowledge Infrastructure, and Chinese Scientific Journal Database. Bias and quality of studies were evaluated by three researchers. Furthermore, a seed-based D-mapping meta-analysis with permutation of subject images (SDM-PSI) was applied to investigate the central mechanisms behind acupuncture treatment at PI. The International Prospective Registry of Systematic Reviews received the protocol for this study. (PROSPERO: CRD42023400086).

Results

The analysis included 305 patients with PI and 116 healthy controls from 11 studies. SDM-PSI analysis showed that patients with PI exhibited increased amplitudes of regional homogeneity and low-frequency fluctuations in the left superior frontal gyrus (1352 voxels, p = 0.0028), right angular gyrus (14 voxels, p = 0.0457), and cerebellum (12 voxels, p = 0.0446). Acupuncture improved the function of right superior frontal gyrus (1, 404 voxels, p = 0.0123), left inferior frontal gyrus (1068 voxels, p = 0.0088), left inferior temporal gyrus (903 voxels, p = 0.0074), left supramarginal gyrus (888 voxels, p = 0.0113), left precuneus (457 voxels, p = 0.0247), right precuneus (302 voxels, p = 0.0191), left supplementary motor area (82 voxels, p = 0.0354), and right parahippocampal gyrus (28 voxels, p = 0.0379). The brain regions affected by non-acupoint acupuncture were all located in the frontal lobe. The Cochrane risk-of bias tool and MINORS5 were used for quality assessment and the included articles had high performance bias and attrition bias.

Conclusion

This coordinate-based meta-analysis found that acupuncture in patients with PI had significant effects on the default mode network, particularly on the frontal lobe and precuneus, and that non-acupoint acupuncture may provide some benefit to frontal brain region function.

Systematic review registration

PROSPERO: CRD42023400086.

Relationships among insomnia, executive function, and suicidal ideation in depressed outpatients: A mediation analysis

Insomnia is a risk factor for suicide, and both are associated with cognitive problems. However, prior research has not examined insomnia, cognition, and suicidal ideation within one sample. We describe cross-sectional associations among insomnia, psychomotor speed, set shifting, and suicidal ideation in 85 depressed adults. Greater insomnia was associated with slower psychomotor speed, while slower psychomotor speed was associated with a greater level (i.e., elaboration of suicide planning) and intensity of suicidal ideation in the past week. Slower set shifting was associated with a greater level and intensity of suicidal ideation in the past week. Mediation analysis indicated that psychomotor speed and set shifting both had a significant total effect on the intensity of suicidal ideation in the past week; set shifting also had a significant total effect on the sum of intensity and suicidal ideation level in the past week. The level of insomnia explained only small percentages of the total effect of either psychomotor speed or set shifting on the intensity of suicidal ideation and the sum of intensity and suicidal ideation level. The findings in this sample demonstrate significant associations of slower psychomotor speed and set shifting with suicidal ideation, with negligible contribution from insomnia.

Insomnia disorder with objective short sleep duration (ISS) phenotype and cognitive performance: a systematic review and meta-analysis

OBJECTIVE

Insomnia disorder with objective short sleep duration (ISS) has been considered as a biologically severe subtype. The aim of this meta-analysis was to reveal the association of the ISS phenotype and cognitive performance.

METHODS

We searched PubMed, EMBASE, and the Cochrane Library for studies that observed an association of cognitive performance and insomnia with objective short sleep duration (ISS) phenotype. The "metafor" and "MAd" packages in R software (version 4.2.0) were used to calculate the unbiased standardized mean difference (Hedge's g), which was adjusted so that a negative value indicated worse cognitive performance.

RESULTS

The pooled analysis with 1339 participants revealed that the ISS phenotype was associated with overall cognitive impairments (Hedges' g = - 0.56 [- 0.89, - 0.23]), as well as specific cognitive domains including attention (Hedges' g = - 0.86 [- 1.25, - 0.47]), memory (Hedges' g = - 0.47 [- 0.82, - 0.12]), and executive function (Hedges' g = - 0.39 [- 0.76, - 0.02]). However, cognitive performance was not significantly different between insomnia disorder with objective normal sleep duration (INS) and good sleepers (p > .05).

CONCLUSION

Insomnia disorder with the ISS phenotype, but not the INS phenotype, was associated with cognitive impairments, suggesting the possible utility of treating the ISS phenotype to improve cognitive performance.

Temporal relations between peripheral and central arousals in good and poor sleepers

Good sleepers and patients with insomnia symptoms (poor sleepers) were tracked with two measures of arousal; conventional polysomnography (PSG) for electroencephalogram (EEG) assessed cortical arousals, and a peripheral arterial tonometry device was used for the detection of peripheral nervous system (PNS) arousals associated with vasoconstrictions. The relationship between central (cortical) and peripheral (autonomic) arousals was examined by evaluating their close temporal dynamics. Cortical arousals almost invariably were preceded and followed by peripheral activations, while large peripheral autonomic arousals were followed by cortical arousals only half of the time. The temporal contiguity of these two types of arousals was altered in poor sleepers, and poor sleepers displayed a higher number of cortical and peripheral arousals compared with good sleepers. Given the difference in the number of peripheral autonomic arousals between good and poor sleepers, an evaluation of such arousals could become a means of physiologically distinguishing poor sleepers.

Insomnia with objective short sleep duration in women with temporomandibular joint disorder: quantitative sensory testing, inflammation and clinical pain profiles

OBJECTIVES/BACKGROUND

Temporomandibular joint disorder (TMD) is a disabling facial pain syndrome with a high prevalence of insomnia that primarily affects women. Insomnia with objective short sleep duration (ISSD) is an emerging phenotype linked to cardiometabolic morbidity and increased mortality. The present report examines the association of ISSD on clinical and laboratory pain and systemic inflammation in TMD.

METHODS

We collected baseline data from 128 women with TMD and insomnia as part of a clinical trial evaluating psychological interventions for sleep and pain. Participants completed self-report questionnaires, one-night polysomnography, a two-week actigraphy assessment, quantitative sensory testing (QST) to assess cold pain tolerance, pain sensitivity and central sensitization and circulating Interleukin-6 levels were measured to assess systemic inflammation.

RESULTS

24.2% (n = 31) of the sample met criteria for ISSD [polysomnography (sleep duration <6 h)]. Compared to those with insomnia and normal sleep duration, ISSD were older (40.4 vs. 34.9,p < 0.05) and a greater proportion self-identified as Black (48.4% vs 11.3%,p < 0.001). Multivariate regressions revealed that ISSD endorsed higher self-report pain severity and functional limitation of the jaw. ISSD also demonstrated increased generalized pain sensitivity, enhanced central sensitization, cold pressor tolerance and higher resting interleukin-6 levels.

CONCLUSIONS

This is the first study to characterize the ISSD phenotype in a chronic pain sample and expand the scope of its negative health outcomes to chronic pain. ISSD may be an important chronic pain phenotype associated with a more severe clinical and laboratory pain profile, and future studies should focus on implications for treatment response and disease trajectory.

CLINICAL TRIAL

ClinicalTrials.gov Identifier: NCT01794624.

Hypothalamic-pituitary-adrenal (HPA) axis response to exogenous corticotropin-releasing hormone (CRH) is attenuated in men with chronic insomnia

Although insomnia is by far the most common sleep disorder, our understanding of its neurobiology is limited. Insomnia, particularly when associated with objective sleep disturbance, has been associated with activation of the hypothalamic-pituitary-adrenal axis. The objective of this experimental study was to compare the response of the hypothalamic-pituitary-adrenal axis to ovine corticotropin-releasing hormone, a stress test, in men with insomnia versus controls. Circulating adrenocorticotropic hormone and cortisol levels were assayed before (-30 min, -15 min), at (0 min) and after (+5 min, +15 min, +30 min, +60 min, +90 min, +120 min) exogenous ovine corticotropin-releasing hormone administration in 23 men (11 insomnia, 12 controls), who underwent four consecutive nights of in-lab polysomnography. Men with insomnia compared with controls demonstrated markedly and significantly shorter total sleep time (368.4 ± 8.99 min versus 411.61 ± 8.61 min; p < 0.01) and lower sleep efficiency (76.77 ± 1.80% versus 86.04 ± 1.72%; p < 0.01) on polysomnography, and showed decreased adrenocorticotropic hormone and cortisol levels after ovine corticotropin-releasing hormone administration. Adrenocorticotropic hormone levels at 15 min and 30 min were significantly lower in men with insomnia than in controls (p < 0.05). Similarly, the peak levels of cortisol at +60 min, and the total and net area under the curve levels of this hormone were significantly lower in men with insomnia than controls (all p < 0.01). Adrenocorticotropic hormone and cortisol response to ovine corticotropin-releasing hormone administration was attenuated in men with insomnia associated with objective sleep disturbance, suggesting that objectively defined insomnia subtypes have a disrupted hypothalamic-pituitary-adrenal axis function and highlight the need to develop treatments targeting the underlying hypothalamic-pituitary-adrenal axis dysregulation.

The role of sleep disturbance and inflammation for spatial memory

Spatial memory is a brain function involved in multiple behaviors such as planning a route or recalling an object's location. The formation of spatial memory relies on the homeostasis of various biological systems, including healthy sleep and a well-functioning immune system. While sleep is thought to promote the stabilization and storage of spatial memories, considerable evidence shows that the immune system modulates neuronal processes underlying spatial memory such as hippocampal neuroplasticity, long-term potentiation, and neurogenesis. Conversely, when sleep is disturbed and/or states of heightened immune activation occur, hippocampal regulatory pathways are altered, which - on a behavioral level - may result in spatial memory impairments. In this Brief Review, I summarize how sleep and the immune system contribute to spatial memory processes. In addition, I present emerging evidence suggesting that sleep disturbance and inflammation might jointly impair spatial memory. Finally, potentials of integrated strategies that target sleep disturbance and inflammation to possibly mitigate risk for spatial memory impairment are discussed.

Objective Measures of Cognitive Performance in Sleep Disorder Research

Neurocognitive tests offer objective and reliable assessment of patients' status and progress. However, there is no consensus on how to use neurocognitive assessment in sleep disorder research. An effective use of neurocognitive assessment must be based on standardized practices and have a firm theoretic basis. The aim of this review is to offer an overview of how different tests have been used in the field, mapping each test onto a corresponding cognitive domain and propose how to move forward with a suggested cognitive battery of tests covering all major cognitive domains.

Insomnia with objective short sleep duration is associated with cognitive impairment: a first look at cardiometabolic contributors to brain health

STUDY OBJECTIVES

Insomnia with objective short sleep duration has been previously associated with adverse cardiometabolic health outcomes as well as poorer cognitive performance in otherwise noncognitively impaired adults. However, studies demonstrating an increased prevalence of cognitive impairment (CI) in this insomnia phenotype are lacking.

METHODS

We analyzed data from Penn State Adult Cohort (N = 1,524; 48.9 ± 13.4 years; 53.4% women). Self-reported sleep difficulty was defined as normal sleep (n = 899), poor sleep (n = 453), and chronic insomnia (n = 172). Objective short sleep duration was defined as less than 6-h of sleep, based on in-lab, 8-h polysomnography. CI (n = 155) and possible vascular cognitive impairment (pVCI, n = 122) were ascertained using a comprehensive neuropsychological battery. Analyses adjusted for age, sex, race, education, body mass index, apnea/hypopnea index, smoking, alcohol, psychoactive medication, and mental and physical health problems.

RESULTS

Participants who reported poor sleep or chronic insomnia and slept objectively less than 6 hours were associated with a 2-fold increased odds of CI (OR = 2.06, 95% confidence limits [CL] = 1.15-3.66 and OR = 2.18, 95% CL = 1.07-4.47, respectively) and of pVCI (OR = 1.94, 95% CL = 1.01-3.75 and OR = 2.33, 95% CL = 1.07-5.06, respectively). Participants who reported poor sleep or chronic insomnia and slept objectively more than 6 hours were not associated with increased odds of either CI (OR = 0.72, 95% CL = 0.30-1.76 and OR = 0.75, 95% CL = 0.21-2.71, respectively) or pVCI (OR = 1.08, 95% CL = 0.42-2.74 and OR = 0.76, 95% CL = 0.16-3.57, respectively).

CONCLUSIONS

Insomnia with objective short sleep duration is associated with an increased prevalence of CI, particularly as it relates to cardiometabolic health (i.e. pVCI). These data further support that this insomnia phenotype may be a more biologically severe form of the disorder associated with cardiovascular, cerebrovascular, and neurocognitive morbidity.

Hyperarousal and Insomnia in Survivors of Cancer

BACKGROUND

Cancer survivors are prone to insomnia due to the physical and psychological sequelae of cancer and treatment. Individuals with insomnia may present symptoms of hyperarousal. Cancer survivors with insomnia and trait hyperarousal may require different clinical treatments than patients with insomnia without trait hyperarousal. To our knowledge, no study has examined these factors previously. This study examined the relation between insomnia and trait hyperarousal in cancer survivors.

METHODS

The sample included 160 individuals with previous cancer diagnoses who met DSM-5 criteria for insomnia disorder. Measures were collected with cross-sectional batteries of questionnaires, including the Insomnia Severity Index (ISI) and Hyperarousal Scale (HAS). This study is based on baseline data collected in a randomized clinical trial comparing CBT-I to acupuncture for cancer survivors with insomnia (Garland, Gehrman, Barg, Xie, & Mao, 2016).

RESULTS

Hyperarousal was positively associated with insomnia (ISI total score) in bivariate correlations (r = .350, p < .01) and linear regressions (F = 22.06, p < .001). In bivariate correlations, hyperarousal was related to perceptions about the consequences of disturbed sleep rather than reported sleep patterns. For example, hyperarousal was positively related to reported satisfaction (r = .159, p < .05) and worry about sleep (r = .415, p < .01), but not to falling asleep, staying asleep, or awakening too early. In regressions, younger age, insomnia duration, and worry about sleep were uniquely associated with hyperarousal when adjusting for insomnia (B = 0.200, B = 0.177, B = -0.182, p < .05).

CONCLUSIONS

Hyperarousal is associated with psychological appraisal of insomnia rather than reported sleep pattern. Younger age and longer duration of insomnia are associated with trait hyperarousal. These findings suggest targeting trait hyperarousal with amplified psychological treatment may lead to more personalized, effective treatment for insomnia.

The Different Faces of Insomnia

Objectives: The identification of clinically relevant subtypes of insomnia is important. Including a comprehensive literature review, this study also introduces new phenotypical relevant parameters by describing a specific insomnia cohort. Methods: Patients visiting the sleep center and indicating self-reported signs of insomnia were examined by a sleep specialist who confirmed an insomnia diagnosis. A 14-item insomnia questionnaire on symptoms, progression, sleep history and treatment, was part of the clinical routine. Results: A cohort of 456 insomnia patients was described (56% women, mean age 52 ± 16 years). They had suffered from symptoms for about 12 ± 11 years before seeing a sleep specialist. About 40-50% mentioned a trigger (most frequently psychological triggers), a history of being bad sleepers to begin with, a family history of sleep problems, and a negative progression of insomnia. Over one third were not able to fall asleep during the day. SMI (sleep maintenance insomnia) symptoms were most frequent, but only prevalence of EMA (early morning awakening) symptoms significantly increased from 40 to 45% over time. Alternative non-medical treatments were effective in fewer than 10% of cases. Conclusion: Our specific cohort displayed a long history of suffering and the sleep specialist is usually not the first point of contact. We aimed to describe specific characteristics of insomnia with a simple questionnaire, containing questions (e.g., ability to fall asleep during the day, effects of non-medical therapy methods, symptom stability) not yet commonly asked and of unknown clinical relevance as yet. We suggest adding them to anamnesis to help differentiate the severity of insomnia and initiate further research, leading to a better understanding of the severity of insomnia and individualized therapy. This study is part of a specific Research Topic introduced by Frontiers on the heterogeneity of insomnia and its comorbidity and will hopefully inspire more research in this area.

Linking insomnia and OCD symptoms during the coronavirus pandemic: Examination of prospective associations

There is considerable concern in the mental health community about the psychological consequences of the coronavirus pandemic and who may be most vulnerable. Obsessive-compulsive disorder (OCD) symptoms may be particularly sensitive to the context of the pandemic. Previous research suggests insomnia symptoms may contribute to increased OCD symptoms over time, particularly during times of stress, such as the pandemic. The present study examined pre-coronavirus outbreak insomnia symptoms as a predictor of post-coronavirus outbreak OCD symptoms in a sample of community adults who completed a 2016 survey study and were re-contacted on April 1, 2020 (N = 369). Results revealed a small significant increase in OCD symptoms following the coronavirus outbreak and a small significant decrease in insomnia symptoms. Pre-coronavirus outbreak insomnia symptoms significantly predicted increases in post-coronavirus outbreak OCD symptoms. Similar results were found for specific OCD symptom facets with the exception of washing and hoarding symptoms, which were unrelated to pre-coronavirus insomnia symptoms. There was no evidence for a reverse effect of prior OCD symptoms on insomnia symptoms during the pandemic. These findings suggest those with insomnia symptoms prior to the coronavirus pandemic may be vulnerable to increases in some OCD symptoms during the pandemic. The implications for preventing adverse psychological responses during the coronavirus pandemic are discussed.

Effects of Presleep Cognitive Intrusions on Subjective Sleep and Next-Day Cognitive Performance in Insomnia

Presleep cognitive intrusions about next-day activities, or proprioceptive and environmental stimuli, are thought to trigger insomnia in neurocognitive models. Recent research showed that intrusive cognitions at bedtime may interact with sleep in influencing next-day emotional functioning; their effects on cognitive functioning, however, is largely unknown. We tested the effects of presleep cognitive intrusions on subjective sleep and next-day cognitive performance in 80 participants, either with chronic insomnia or good sleepers. Presleep intrusions were inspected using a validated questionnaire and sleep was assessed with a sleep diary. Cognitive functioning the following morning was measured using a task-switching paradigm assessing executive functions. Structural equation modeling with manifest variables (i.e., path analysis) shows that presleep cognitive intrusions predicted increased sleep onset latency and wake after sleep onset, and lowered sleep efficiency. Moreover, task-switching accuracy was independently predicted by presleep cognitive intrusions in the previous night in those with insomnia but not in controls, beyond the effects of trait anxiety, task-switching components, and previous night's sleep. Findings confirm detrimental effects of presleep intrusions on sleep continuity and suggest the presence of links between presleep conscious activity and next-day executive performance in patients with insomnia, with the need to better elucidate potential mediators.

Effects of insomnia symptoms and objective short sleep duration on memory performance in youths

Sleep quantity and quality are both important for optimal development and functioning during youth. Yet few studies have examined the effects of insomnia symptoms and objective short sleep duration on memory performance among adolescents and young adults. One-hundred and ninety participants (female: 61.6%) aged from 12 to 24 years completed this study. All participants underwent a clinical interview, a 7-day actigraphic assessment, a battery of self-report questionnaires and cognitive tests to assess working memory and episodic memory. Insomnia symptoms were defined as a score ≥ 9 on the Insomnia Severity Index, and objective short sleep duration was defined as average total sleep time less than 7 hr for those aged 12-17 years, and 6 hr for those aged 18 years and above as assessed by actigraphy. Insomnia symptoms were significantly associated with worse self-perceived memory (p < .05) and poorer performance on the digit span task (p < .01), but not the dual N-back task and verbal learning task. There was no significant difference in any of the memory measures between participants with objective short sleep duration and their counterparts. No interaction effect was found between insomnia and short sleep duration on any of the objective memory outcomes. Insomnia symptoms, but not objective short sleep duration, were associated with poorer subjective memory and objective working memory performance in youths. Further studies are needed to investigate the underlying mechanisms linking insomnia and memory impairments, and to delineate the long-term impacts of insomnia on other aspects of neurocognitive functioning in youth.

Onset of regular cannabis use and young adult insomnia: an analysis of shared genetic liability

STUDY OBJECTIVES

Estimate the genetic and environmental influences on the relationship between onset of regular cannabis use and young adult insomnia.

METHODS

In a population-based twin cohort of 1882 twins (56% female, mean age = 22.99, SD = 2.97) we explored the genetic/environmental etiology of the relationship between onset of regular cannabis use and insomnia-related outcomes via multivariate twin models.

RESULTS

Controlling for sex, current depression symptoms, and prior diagnosis of an anxiety or depression disorder, adult twins who reported early onset for regular cannabis use (age 17 or younger) were more likely to have insomnia (β = 0.07, p = 0.024) and insomnia with short sleep on weekdays (β = 0.08, p = 0.003) as young adults. We found significant genetic contributions for the onset of regular cannabis use (a2 = 76%, p < 0.001), insomnia (a2 = 44%, p < 0.001), and insomnia with short sleep on weekdays (a2 = 37%, p < 0.001). We found significant genetic correlations between onset of regular use and both insomnia (rA = 0.20, p = 0.047) and insomnia with short sleep on weekdays (rA = 0.25, p = 0.008) but no significant environmental associations between these traits.

CONCLUSIONS

We found common genetic liabilities for early onset of regular cannabis use and insomnia, implying pleiotropic influences of genes on both traits.

Dysfunction of processing task-irrelevant emotional faces in primary insomnia patients: an evidence from expression-related visual MMN

PURPOSE

According to the cognitive processing perspectives, patients with insomnia have insufficient neural management of expressional information. In this study, we compared the pre-attentive processing function of task-irrelevant facial expressions in patients with primary insomnia (PI) and matched healthy controls, with expression-related mismatch negativity (EMMN) elicited by emotional faces as the indicator.

METHODS

Using three schematic facial expressions (neutral, happy, and sad) as task-irrelevant stimuli, we investigated the visual processing of PI patients (n = 22) and healthy subjects (n = 22) in an expression-related oddball paradigm designed to elicit the visual N170 and EMMN component. After recording and analyzing the electroencephalogram of all participants, amplitude analysis of N170 and EMMN was eventually conducted under corresponding time window.

RESULTS

Compared with control group, the amplitude of sad-EMMN component was significantly attenuated in patients with PI, while no remarkable difference was observed under the happy condition. In addition, negative cognitive bias was further validated in the control group, but not presented in the PI group.

CONCLUSION

The current data suggest dysfunctional expressional information processing in PI patients, accompanied by the disorganization of high level perceptual strategy of processing facial emotional expression.

The effects of digital cognitive behavioral therapy for insomnia on cognitive function: a randomized controlled trial

Study Objectives

We sought to examine the impact of digital cognitive behavioral therapy (dCBT) for insomnia on both self-reported cognitive impairment and objective cognitive performance.

Methods

The Defining the Impact of Sleep improvement on Cognitive Outcomes (DISCO) trial was an online, two-arm, single-blind, randomized clinical trial of dCBT versus wait-list control. Participants were aged 25 years and older, met DSM-5 diagnostic criteria for insomnia disorder, and reported difficulties with concentration or memory. Assessments were carried out online at baseline, and 10 and 24 weeks post-randomization. The primary outcome measure was self-reported cognitive impairment, assessed with the British Columbia Cognitive Complaints Inventory (BC-CCI). Secondary outcomes included tests of cognitive performance, insomnia symptoms, cognitive failures, fatigue, sleepiness, depression, and anxiety.

Results

Four hundred and ten participants with insomnia were recruited and assigned to dCBT (N = 205) or wait-list control (N = 205). At 10 weeks post-randomization the estimated adjusted mean difference for the BC-CCI was −3.03 (95% CI: −3.60, −2.47; p &lt; 0.0001, d = −0.86), indicating that participants in the dCBT group reported less cognitive impairment than the control group. These effects were maintained at 24 weeks (d = −0.96) and were mediated, in part, via reductions in insomnia severity and increased sleep efficiency. Treatment effects in favor of dCBT, at both 10 and 24 weeks, were found for insomnia severity, sleep efficiency, cognitive failures, fatigue, sleepiness, depression, and anxiety. We found no between-group differences in objective tests of cognitive performance.

Conclusions

Our study shows that dCBT robustly decreases self-reported cognitive impairment at post-treatment and these effects are maintained at 6 months.

Insomnia and Neurocognitive Functioning in Adult Survivors of Childhood Cancer

Background

In noncancer populations, insomnia is known to affect neurocognitive processes. Although the prevalence of insomnia appears to be elevated in survivors of childhood cancer, relatively little is known about its association with neurocognitive performance in this at-risk population.

Methods

A total of 911 survivors (51.9% female; mean [SD] age, 34 [9.0] years; time since diagnosis, 26 [9.1] years) completed direct assessments of attention, memory, processing speed, and executive functioning and self-reported symptoms of sleep (Pittsburgh Sleep Quality Index), fatigue (Functional Assessment of Chronic Illness Therapy-Fatigue), and daytime sleepiness (Epworth Sleepiness Scale). Sex-stratified general linear models were used to examine associations between insomnia and neurocognitive performance, with adjustment for treatment exposures and chronic health conditions. All statistical tests were two-sided.

Results

Insomnia was reported by 22.1% of females and 12.3% of males (P < .001). After adjustment for neurotoxic treatment exposures, insomnia (vs healthy sleepers with no daytime fatigue or sleepiness) was associated with worse neurocognitive performance in the domains of verbal reasoning, memory, attention, executive function, and processing speed (verbal reasoning: males β = −0.34, P = .04, females β = −0.57, P < .001; long-term memory: males β = −0.60, P < .001, females β = −0.36, P = .02; sustained attention: males β = −0.85, P < .001, females β = −0.42, P = .006; cognitive flexibility: males β = −0.70, P = .002, females β = −0.40, P = .02). Self-reported sleep disturbance without daytime fatigue or sleepiness or daytime fatigue or sleepiness alone were not consistently associated with poorer neurocognitive performance.

Conclusions

Insomnia was highly prevalent and contributed to the neurocognitive burden experienced by adult survivors of childhood cancer. Treatment of insomnia may improve neurocognitive problems in survivors.

Hyperarousal Scale: Italian Cultural Validation, Age and Gender Differences in a Nonclinical Population

Objectives. Studies on hyperarousal have increasingly developed in the last decade. Nevertheless, there are still very few valid measures of hyperarousal. The aim of the study is to verify the psychometric properties of the Italian version of the Hyperarousal Scale (H-Scale), in order to provide researchers with a valid measure for the target population. Method. The questionnaire was translated, back-translated, pre-tested, and cross-culturally adapted. Subsequently, the Italian version of the H-Scale, the Anxiety Sensitivity Index (ASI-3) and the Health Survey Questionnaire (SF-36) were administered to 982 adults, 456 males and 526 females, aged from 18 to 80 years (M = 35.61 ± 12.47). Results. Cronbach’s alpha of the translated H-Scale was 0.81. Furthermore, positive correlations with the ASI-3 and negative correlations with the SF-36 emerged. The H-Scale is also sensitive to catch age and gender differences. Conclusions. The Italian version of the H-Scale demonstrated good reliability and validity. Its sufficient discriminative and evaluative psychometric properties provide the theoretical evidence for further application in evidence-based research studies.

Objective Short Sleep Duration is Related to the Peripheral Inflammasome Dysregulation in Patients with Chronic Insomnia

OBJECTIVE

Insomnia with objective short sleep duration (IOSSD) is associated with an increased risk of cardiovascular morbidity, diabetes, neurocognitive impairment, and mortality. Inflammation is believed to be one of the main links between IOSSD and these diseases. The role of nucleotide-binding domain and leucine-rich repeat protein-3 (NLRP3) inflammasome in inducing activation of inflammatory signaling in IOSSD is not clear. In this study, we investigated the expression of NLRP3 inflammasome in patients with IOSSD to clarify this issue.

METHODS

Thirty-six patients with insomnia and 20 age- and sex-matched healthy controls were sequentially recruited. Subjects were categorized into three groups: IOSSD (sleep duration < 6h, n=20), insomnia with objective normal sleep duration (IONSD, sleep duration ≥ 6h, n=16) and healthy controls (n=20). Objective sleep parameters were measured by overnight polysomnography. Peripheral NLRP3 inflammasome protein levels [NLRP3, apoptosis-associated speck-like protein containing a CARD (ASC), caspase l] and cytokines [interleukin (IL)-1β and IL-18] were assessed by Western blotting and ELISA, respectively.

RESULTS

IOSSD group showed significantly increased protein expressions of ASC and caspase-1 compared to IONSD and healthy controls and significantly increased IL-18 levels compared to healthy controls. On correlation analysis, total sleep time showed an inverse correlation with NLRP3, ASC, IL-18, and IL-1β levels. Wake after sleep onset (WASO) showed a positive correlation with NLRP3, ASC, caspase-1, and IL-1β levels. N3 sleep ratio showed a significant negative correlation with NLRP3, ASC, and IL-18 levels.

CONCLUSION

The current study demonstrated upregulation of NLRP3 inflammasome in IOSSD. Short sleep duration, decreased slow wave sleep, and sleep fragmentation may contribute to dysregulation of NLRP3 inflammasome.

Insomnia and Cognitive Performance

Insomnia is the most common sleep problem, affecting between 30% and 50% in the general adult population. Insomnia is characterized by difficulty initiating and maintaining sleep, along with dissatisfaction with sleep quality or quantity. Insomnia complaints are linked to clinically significant distress or impairment in key areas of functioning, especially daytime cognitive performance. Cognitive impairments related to insomnia are subtle, and may represent distinct differences from those seen in other sleep disorders. This article updates and summarizes the recent literature investigating cognitive impairments in individuals with insomnia, and identifies the cognitive domains of functioning that are consistently impaired.

Cognitive performance in patients with implantable cardioverter defibrillators: Associations with objective sleep duration, age and anxiety

Sleep disturbance and anxiety are highly prevalent in patients with implantable cardiac defibrillators (ICDs). There is limited research, however, on the associations between cognitive performance and sleep parameters, age and anxiety. Forty-one patients with ICDs and self-reported sleep disturbance completed 14 days of actigraphy (Mage  = 60.3, SD = 12.3) measuring total sleep time (TST), and a computerized cognitive test battery measuring processing speed and attention (i.e. simple reaction time and symbol digit modality task [SDMT]) and executive function (i.e. flanker task, letter series task and N-back task). Multiple regressions determined whether independent effects of TST, age and anxiety, as well as interactive effects of TST and age, predicted cognitive performance. TST predicted performance on two tasks of executive function (i.e. letter series and N-back task), as well as an attentional vigilance and processing speed task (i.e. SDMT), and this did not depend on patient age. On letter series, N-back and SDMT, longer TST predicted better performance. Increasing age was a predictor of worse performance on SDMT and flanker tasks. No other predictors were associated with task performance. Results show that sleep duration, not anxiety, may be an important predictor of higher-order cognitive functioning and lower-order tasks measuring processing speed and attention in ICD patients, with longer sleep duration showing greater benefit for performance.

Insomnia, sleep duration and academic performance: a national survey of Norwegian college and university students

Objective

The aim of this study was to evaluate the associations between insomnia, sleep duration and self-reported academic performance/failure in a large sample of Norwegian college and university students.

Methods

This cross-sectional survey comprised 50,054 full-time students (69% women) aged 18-35 years (mean age 23.2, standard deviation (SD) = 3.3), with a response rate of 31%. Binary logistic regression analyses were conducted to examine the associations between the independent variables, an approximation of the insomnia disorder and sleep duration, and the dependent variables, failed examinations and delayed study progress.

Results

The results showed that insomnia was associated with a higher risk of failed examinations (adjusted for background variables, odds ratio (OR_adjusted) = 1.31, 95% confidence interval (CI) 1.25-1.37, p < 0.001) and delayed study progress (OR_adjusted = 1.32, 95% CI: 1.22-1.42, p < 0.001). A curvilinear relationship between sleep duration and risk of academic failure was demonstrated, where both sleeping less than 5 h, and 10 h or more, were associated with higher odds of failed study examinations, compared to with sleeping 7-9 h (OR_adjusted = 1.46, 95% CI: 1.33-1.63, p < 0.001 and OR_adjusted = 1.53, 95% CI: 1.33-1.75, p < 0.001, respectively). Insomnia and deviations from an optimal sleep duration may have notable consequences for academic success in higher education.

Executive Functions in Insomnia Disorder: A Systematic Review and Exploratory Meta-Analysis

Background: Executive functions (EFs) are involved in the control of basic psychological processes such as attention and memory and also contribute to emotion regulation. Research on the presence of EFs impairments in insomnia yielded inconsistent results. Therefore, we performed a systematic review of the literature on three EFs: inhibitory control, working memory, and cognitive flexibility in adults with insomnia in order to investigate the presence and magnitude of insomnia-related EFs impairments. Methods: PubMed, Scopus, Medline, and PsycINFO were searched. Risk of bias assessment of included studies was performed by two independent researchers. Findings were summarised using both a narrative approach and meta-analysis. Cohen's d was calculated at 95% confidence interval (CI) as effect size of between groups differences. Results: Twenty-eight studies comparing adult individuals with a diagnosis of insomnia and healthy controls on neuropsychological measures of EFs were included. Narrative synthesis revealed substantial variability across study findings. Factors that were primarily hypothesised to account for this variability are: objective sleep impairments and test sensitivity. Exploratory meta-analysis showed impaired performance of small to moderate magnitude in individuals with insomnia as compared to controls in reaction times, but not accuracy rates, of inhibitory control (d = -0.32, 95% CI: -0.52 to -0.13) and cognitive flexibility tasks (d = -0.30, 95% CI: -0.59 to -0.01). Performance in working memory tasks was also significantly impacted (d = -0.19, 95% CI: -0.38 to -0.00). Effects sizes were larger when insomnia was associated with objective sleep impairments, rather than normal sleep. Conclusions: We gathered evidence supporting small to moderate deficits in EFs in individuals with insomnia. Due to the small sample size results should be considered preliminary and interpreted carefully.