The effect of physical exercise interventions on insomnia: A systematic review and meta-analysis.

6-10 % of Europeans suffer from chronic insomnia. They have a higher risk to develop mental and cardiovascular diseases. Treatment of insomnia primarily recommended by the European guideline is cognitive behavioral therapy for insomnia (CBT-I). A quarter of patients treated with CBT-I do not respond sufficiently. The objective of this paper is to examine the influence of exercise interventions on insomnia by conducting a systematic review and meta-analysis. A database search was conducted, including randomized controlled trials (RCT) in which participants had received a diagnosis of insomnia or experienced symptoms thereof. Exercise interventions had to meet the definition of the World Health Organization (WHO), and their implementation was reported according to the FITT (Frequency, Intensity, Time and Type) principle. There was an inactive control and subjective or objective sleep parameters as outcomes. Nineteen studies were included. Results showed a significant improvement for objective (standardized mean difference, SMD = 0.37; confidence interval, CI = [0.17; 0.57]) as well as subjective (SMD = 0.90; CI = [0.61; 1.19]) sleep parameters. Meta-regression showed that the effect increased with intensity of intervention, mean age of participants and percentage of females, but showed high heterogeneity across studies. These results suggest great potential for treating insomnia. Conducting larger trials is advisable to provide precise recommendations.

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.

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.

Towards the neurobiology of insomnia: A systematic review of neuroimaging studies.

Insomnia disorder signifies a major public health concern. The development of neuroimaging techniques has permitted to investigate brain mechanisms at a structural and functional level. The present systematic review aims at shedding light on functional, structural, and metabolic substrates of insomnia disorder by integrating the available published neuroimaging data. The databases PubMed, PsycARTICLES, PsycINFO, CINAHL and Web of Science were searched for case-control studies comparing neuroimaging data from insomnia patients and healthy controls. 85 articles were judged as eligible. For every observed finding of each study, the effect size was calculated from standardised mean differences, statistic parameters and figures, showing a marked heterogeneity that precluded a comprehensive quantitative analysis. From a qualitative point of view, considering the findings of significant group differences in the reported regions across the articles, this review highlights the major involvement of the anterior cingulate cortex, thalamus, insula, precuneus and middle frontal gyrus, thus supporting some central themes in the debate on the neurobiology of and offering interesting insights into the psychophysiology of sleep in this disorder.

Insomnia and REM sleep instability.

In this narrative review, we give an overview of the concept of rapid eye movement sleep instability and its reported implications in the context of insomnia. The term rapid eye movement sleep instability was coined to describe the observation of a modified rapid eye movement quality in insomnia, characterized by an increased tendency of perceiving rapid eye movement sleep as wake, a small but consistent rapid eye movement sleep reduction and an increased rapid eye movement sleep arousal index. Current research highlights relationships that are transdiagnostic in nature, corresponding to the known interaction of insomnia with many psychiatric disorders, and showing relationships to chronic stress and anxiety disorders.

Complementary and alternative treatments for insomnia disorder: a systematic umbrella review.

Insomnia is a common disorder and cognitive behavioural therapy for insomnia (CBT-I) is recommended as first-line treatment. However, CBT-I is not widely distributed and infrequently available while medication is not indicated for long-term use. To close this evident gap in supply, alternative treatments could be utilised. High-quality research on this topic is scarce, and there is currently no comprehensive publication on the effectiveness of alternative treatments. To address this pressing question, we systematically summarised the existing research on alternative treatments for insomnia. A comprehensive search of systematic reviews and (network) meta-analyses of randomised controlled trials investigating the efficacy of alternative treatments compared to waiting-list control or placebo in adults with insomnia disorder with or without comorbidities was conducted in PubMed, MEDLINE, PsycInfo, and PsycArticles on December 6, 2022, yielding 391 records. Finally, 15 eligible studies were included. Evidence on acupuncture, exogenous melatonin, mind-body interventions and exercise, repetitive transcranial magnetic stimulation (rTMS), valerian, and light exposure was found. Acupuncture, rTMS and mind-body exercises significantly improved sleep quality and insomnia severity but effects on objectively assessed outcomes were inconclusive. Melatonin led to a reduction in both self-reported and objectively assessed sleep onset latency. Light exposure and valerian did not significantly improve sleep outcomes. Overall, the quality of studies was rated as low. Results indicate that alternative treatments are effective mostly on subjective outcomes. However, evidence on the efficacy of some intervention types is sparse and there is a need for high-quality original studies. Future research could investigate whether combining different alternative treatment aspects with CBT-I improves individual treatment.

Insomnia symptoms as risk factor for somatic disorders: An umbrella review of systematic reviews and meta-analyses.

The objective of this umbrella review is to present a comprehensive summary of systematic reviews and meta-analyses on the longitudinal association between insomnia and the risk of developing somatic disorders. Pubmed, Medline, CINAHL, PsycInfo and PsycArticles were searched until 16 December 2022. Fourteen systematic reviews and meta-analyses met the inclusion criteria. Results suggest that insomnia symptoms (i.e. aspects of disturbed sleep continuity as a single symptom) convey a risk factor for cardiovascular diseases, hypertension and thyroid cancer. The presence of insomnia symptoms may also enhance the risk for obesity, cognitive decline and dementia-however, results are contradictory and not conclusive here. Results do not suggest an association between insomnia symptoms and mortality. No conclusions can be drawn regarding insomnia disorder because the reviews did not ensure a valid diagnosis. It remains unclear what proportion of participants with insomnia symptoms fulfil diagnostic criteria for insomnia disorder and/or suffer from an organic sleep disorder such as sleep-related breathing disorder. Moreover, most of the included reviews were assessed to have critically low confidence according to the AMSTAR-2 tool. Inconsistent definitions of insomnia and methodological unclarities further underline that results should be interpreted with caution. There is a need for future longitudinal studies that focus on a careful definition and differential diagnosis of both insomnia and the outcome.

A multivariate blood metabolite algorithm stably predicts risk and resilience to major depressive disorder in the general population.

BACKGROUND: Socioeconomic pressures, sex, and physical health status strongly influence the development of major depressive disorder (MDD) and mask other contributing factors in small cohorts. Resilient individuals overcome adversity without the onset of psychological symptoms, but resilience, as for susceptibility, has a complex and multifaceted molecular basis. The scale and depth of the UK Biobank affords an opportunity to identify resilience biomarkers in rigorously matched, at-risk individuals. Here, we evaluated whether blood metabolites could prospectively classify and indicate a biological basis for susceptibility or resilience to MDD. METHODS: Using the UK Biobank, we employed random forests, a supervised, interpretable machine learning statistical method to determine the relative importance of sociodemographic, psychosocial, anthropometric, and physiological factors that govern the risk of prospective MDD onset (total n = 15,710). We then used propensity scores to rigorously match individuals with a history of MDD (n = 491) against a resilient subset of individuals without an MDD diagnosis (retrospectively or during follow-up; n = 491) using an array of key social, demographic, and disease-associated drivers of depression risk. 381 blood metabolites and clinical chemistry variables and 4 urine metabolites were integrated to generate a multivariate random forest-based algorithm using 10-fold cross-validation to predict prospective MDD risk and resilience. OUTCOMES: In unmatched individuals, a first case of MDD, with a median time-to-diagnosis of 72 years, can be predicted using random forest classification probabilities with an area under the receiver operator characteristic curve (ROC AUC) of 0.89. Prospective resilience/susceptibility to MDD was then predicted with a ROC AUC of 0.72 (x˜ = 3.2 years follow-up) and 0.68 (x˜ = 7.2 years follow-up). Increased pyruvate was identified as a key biomarker of resilience to MDD and was validated retrospectively in the TwinsUK cohort. INTERPRETATION: Blood metabolites prospectively associate with substantially reduced MDD risk. Therapeutic targeting of these metabolites may provide a framework for MDD risk stratification and reduction. FUNDING: New York Academy of Sciences' Interstellar Programme Award; Novo Fonden; Lincoln Kingsgate award; Clarendon Fund; Newton-Abraham studentship (University of Oxford). The funders had no role in the development of the present study.

Insomnia-A risk factor for mental disorders.

Longitudinal studies observed that individuals suffering from insomnia disorder have a higher vulnerability to develop symptoms of psychopathology compared with good sleepers. Particularly, insomnia disorder has been associated with an increased risk for depression. Previous studies indicate relatively stable effects; however, replication is needed as the last meta-analysis on the topic has been published 4 years ago. We conducted a replication of a previous systematic review and meta-analysis evaluating the longitudinal association between insomnia disorder and psychopathology, including original works published between 2018 and 2022. Literature search was conducted from April 2018 to August 2022 using key words identifying longitudinal studies that evaluate individuals with insomnia disorder compared with good sleepers at baseline, and the onset of all possible mental disorders at long-term follow-up. Only one work was added to the previous sample of studies published in 2019 looking at the longitudinal association between insomnia disorder and depression. Meta-analytic results confirmed the previous observation, with an even higher observed effect for the link between insomnia and depression. This again recognizes insomnia disorder as a possible transdiagnostic process in psychopathology, with consequent important clinical implications. Nevertheless, more longitudinal studies are needed evaluating the link between insomnia disorder and mental disorders.

The Effects of Cognitive Behavioral Therapy for Insomnia on Multidimensional Perfectionism.

Perfectionism is related to insomnia and objective markers of disturbed sleep. This study examined whether multidimensional perfectionism is related to dysfunctional beliefs about sleep, sleep-effort, pre-sleep arousal, and polysomnography-determined markers of sleep among individuals with insomnia. The effects of cognitive behavioral therapy for insomnia (CBT-I) on perfectionism was also examined. This was a secondary analysis of a randomized controlled trial on CBT-I. Forty-three insomnia patients were randomized to treatment (receiving CBT-I) or waitlist control groups. Sleep was recorded using polysomnography at baseline. Participants completed measures of perfectionism, dysfunctional beliefs about sleep, sleep-effort and pre-sleep arousal at baseline and posttreatment. Total perfectionism scores and doubts about action, concern over mistakes and personal standards were each significantly related to increased sleep effort, pre-sleep arousal and dysfunctional beliefs about sleep at baseline. Patients receiving treatment displayed increased total perfectionism scores posttreatment d = .49. In those receiving treatment, levels of organization d = .49 and parental expectations d = .47 were significantly increased posttreatment, relative to baseline. In line with the literature, our results confirm that perfectionism is related to insomnia. Here, insomnia was related to increased sleep effort, pre-sleep arousal and dysfunctional beliefs about sleep. The propensity to maintain a high standard of order and organization may be elevated following CBT-I, considering the treatment protocol expects patients to strictly adhere to a set of clearly defined rules. Levels of parental expectations may be increased following CBT-I since the patient-therapist-relationship may trigger implicit expectations in patients which are reminiscent of their relationship to their parents.

Comparative efficacy of onsite, digital, and other settings for cognitive behavioral therapy for insomnia: a systematic review and network meta-analysis.

Given the limited availability and accessibility of onsite cognitive behavioral therapy for insomnia (CBT-I), other CBT-I settings, such as internet-delivered CBT-I (iCBT-I), have been proposed. The primary aim of the study was to compare the efficacy of available CBT-I settings on insomnia severity. A systematic review and frequentist network meta-analysis of available CBT-I settings was performed. PsycINFO, PsycARTICLES, MEDLINE, PubMed, and CINAHL were searched for randomized controlled trials (RCTs) investigating any CBT-I settings in adults with insomnia disorder. The systematic literature search (3851 references) resulted in 52 RCTs. For the primary outcome insomnia severity, all examined CBT-I settings except smartphone-delivered CBT-I yielded significant effects when compared to WL. Large standardized mean differences were found for individual onsite CBT-I (- 1.27;95%CI - 1.70, - 0.84), group-delivered CBT-I (- 1.00;95%CI - 1.42. - 0.59), telehealth (- 1.28;95%CI - 2.06, - 0.50), and guided bibliotherapy (- 0.99;95%CI - 1.67, - 0.32). Both guided iCBT-I (- 0.71;95%CI - 1.18, - 0.24) and unguided iCBT-I (- 0.78;95%CI - 1.18, - 0.38) yielded medium effect sizes. The results underline that health care systems should intensify their efforts to provide synchronously-delivered CBT-I (individual onsite, group-delivered, and telehealth), and particularly individual onsite CBT-I, given its solid evidence base. Medium to large effect sizes for iCBT-I and guided bibliotherapy indicate that self-help settings may be a viable alternative when synchronously-delivered CBT-I is not available.

How many hours do you sleep? A comparison of subjective and objective sleep duration measures in a sample of insomnia patients and good sleepers.

Our objective was to assess the agreement and linear relationships amongst multiple measures of sleep duration in a sample of patients with insomnia disorder and good sleeper controls. We retrospectively analysed data from 123 patients with insomnia disorder and 123 age- and gender-matched good sleeper controls who completed a simple subjective habitual sleep duration question (Pittsburgh Sleep Quality Index), a sleep diary (5-14 days), 2 nights of polysomnography, and two corresponding morning subjective estimates of sleep duration. Descriptive statistics, linear regression analyses and Bland-Altman plots were used to describe the relationship and (dis)agreement between sleep duration measures. Relationships between polysomnography and the simple question as well as between polysomnography and sleep diary were weak to non-existent. Subjective measures and polysomnography did not agree. Sleep duration measured with the Pittsburgh Sleep Quality Index or sleep diary was about 2 hr above or up to 4 hr below polysomnography-measured sleep duration. Patients with insomnia disorder, on average, reported shorter sleep duration compared with polysomnography, while good sleeper controls, on average, reported longer sleep duration compared with polysomnography. The results suggest that subjective and objective measures apparently capture different aspects of sleep, even when nominally addressing the same value (sleep duration). They disagree in both patients with insomnia disorder and good sleeper controls, but in different directions. Studies assessing sleep duration should take into account both the investigated population and the assessment method when interpreting results. Future studies should continue to investigate possible psychological and physiological correlates of sleep (mis)perception.

Comparative effectiveness of three versions of a stepped care model for insomnia differing in the amount of therapist support in internet-delivered treatment: study protocol for a pragmatic cluster randomised controlled trial (GET Sleep).

INTRODUCTION: It is unclear how internet-delivered cognitive-behavioural therapy for insomnia (CBT-I) can be integrated into healthcare systems, and little is known about the optimal level of therapist guidance. The aim of this study is to investigate three different versions of a stepped care model for insomnia (IG1, IG2, IG3) versus treatment as usual (TAU). IG1, IG2 and IG3 rely on treatment by general practitioners (GPs) in the entry level and differ in the amount of guidance by e-coaches in internet-delivered CBT-I. METHODS AND ANALYSIS: In this randomised controlled trial, 4268 patients meeting International Classification of Diseases, Tenth Revision (ICD-10) criteria for insomnia will be recruited. The study will use cluster randomisation of GPs with an allocation ratio of 3:3:3:1 (IG1, IG2, IG3, TAU). In step 1 of the stepped care model, GPs will deliver psychoeducational treatment; in step 2, an internet-delivered CBT-I programme will be used; in step 3, GPs will refer patients to specialised treatment. Outcomes will be collected at baseline, and 4 weeks, 12 weeks and 6 months after baseline assessment. The primary outcome is insomnia severity at 6 months. An economic evaluation will be conducted and qualitative interviews will be used to explore barriers and facilitators of the stepped care model. ETHICS AND DISSEMINATION: The study protocol was approved by the Ethics Committee of the Medical Centre-University of Freiburg. The results of the study will be published irrespective of the outcome. TRIAL REGISTRATION NUMBER: DRKS00021503.

Insomnia disorder: State of the science and challenges for the future.

Insomnia disorder comprises symptoms during night and day that strongly affect quality of life and wellbeing. Prolonged sleep latency, difficulties to maintain sleep and early morning wakening characterize sleep complaints, whereas fatigue, reduced attention, impaired cognitive functioning, irritability, anxiety and low mood are key daytime impairments. Insomnia disorder is well acknowledged in all relevant diagnostic systems: Diagnostic and Statistical Manual of the American Psychiatric Association, 5th revision, International Classification of Sleep Disorders, 3rd version, and International Classification of Diseases, 11th revision. Insomnia disorder as a chronic condition is frequent (up to 10% of the adult population, with a preponderance of females), and signifies an important and independent risk factor for physical and, especially, mental health. Insomnia disorder diagnosis primarily rests on self-report. Objective measures like actigraphy or polysomnography are not (yet) part of the routine diagnostic canon, but play an important role in research. Disease concepts of insomnia range from cognitive-behavioural models to (epi-) genetics and psychoneurobiological approaches. The latter is derived from knowledge about basic sleep-wake regulation and encompass theories like rapid eye movement sleep instability/restless rapid eye movement sleep. Cognitive-behavioural models of insomnia led to the conceptualization of cognitive-behavioural therapy for insomnia, which is now considered as first-line treatment for insomnia worldwide. Future research strategies will include the combination of experimental paradigms with neuroimaging and may benefit from more attention to dysfunctional overnight alleviation of distress in insomnia. With respect to therapy, cognitive-behavioural therapy for insomnia merits widespread implementation, and digital cognitive-behavioural therapy may assist delivery along treatment guidelines. However, given the still considerable proportion of patients responding insufficiently to cognitive-behavioural therapy for insomnia, fundamental studies are highly necessary to better understand the brain and behavioural mechanisms underlying insomnia. Mediators and moderators of treatment response/non-response and the associated development of tailored and novel interventions also require investigation. Recent studies suggest that treatment of insomnia may prove to add significantly as a preventive strategy to combat the global burden of mental disorders.

HPA axis activity in patients with chronic insomnia: A systematic review and meta-analysis of case-control studies.

Insomnia is a highly prevalent disorder and a state of 24 h hyperarousal is considered as a key factor of this condition. Various physiological markers of hyperarousal have been investigated, including the activity of the HPA axis. However, these studies yielded heterogenous results. The aim of this study was to qualitatively and quantitatively evaluate whether there are differences in cortisol levels, the hormonal end product of the HPA axis, between patients with insomnia and good sleeper controls (GSC). The databases PubMed, Cinahl, PsycInfo, PsycArticles and Web of Science were searched for case-control studies comparing cortisol levels in patients with insomnia and GSC. Twenty studies (449 patients with insomnia, limited to ages 18-70 not taking any medications; 357 GSC) met the inclusion criteria. For each study, standardized mean differences (SMD) were calculated as a measure of effect size. Results suggest that patients with insomnia show moderately increased cortisol levels (SMD = 0.50, 95% CI: [0.21-0.80]). Higher effect sizes were found by including only studies using blood samples in the analysis (SMD = 0.67, 95% CI: [0.15-1.18]). Furthermore, a positive, but insignificant association was found between the extent of objective sleep loss in insomnia patients and group differences in cortisol levels.

Event-related potentials in insomnia reflect altered perception of sleep.

STUDY OBJECTIVES: Insomnia is defined by the subjective complaint of poor sleep as well as daytime impairments. Since polysomnography (PSG) typically shows only modest sleep impairment, some still unidentified property of sleep, not mirrored in PSG, may be modified in insomnia.One possible mechanistic hypothesis is that insomnia patients may be more sensitive to inevitably occurring internal or external stimuli during the night, causing brief sleep disruptions then perceived as wake time. METHODS: Auditory event-related potentials (ERP) to low intensity (50 dB SPL) synthesized guitar tones played continuously throughout two nights of polysomnographically registered sleep were obtained in fifty patients with insomnia disorder (ID, without comorbidities) and 50 age- and sex-matched good sleeper controls (GSC) for each sleep stage and NREM/REM cycle. Phasic and tonic REM were treated as separate stages. Latencies and amplitudes of components P1, N1 and P2 were measured and analyzed by multivariate repeated-measures ANCOVA including effects of group, night, cycle, and age. RESULTS: ID showed reduced P2 amplitudes relative to GSC specifically in phasic REM sleep. The same reduction also correlated with the amount of sleep misperception across groups. Independent component analysis showed a frontal negativity to contribute most to this group difference. CONCLUSIONS: The present finding can be interpreted as increased mismatch negativity (MMN) in ID, reflecting automated detection of change in the auditory system and a concomitant orienting response. Specifically phasic REM sleep appears to be vulnerable to sensory afferences in ID patients, possibly contributing to the perception of being awake. CLINICAL TRIAL INFORMATION: Short name "PERSLEEP 2," URL https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&TRIAL_ID=DRKS00008965, Registration DRKS00008965.

The Association between Diurnal Sleep Patterns and Emotions in Infants and Toddlers Attending Nursery.

BACKGROUND: Childcare programs often include mandatory naptime during the day. Loss of daytime sleep could lead to a moderate-to-large decrease in self-regulation, emotion processing, and learning in early childhood. Nevertheless, daytime sleep has been less accurately studied than nighttime sleep. This study aims to explore the relationship between diurnal sleep habits in nursery settings, nocturnal sleep quality, and post-nap emotional intensity in infants and toddlers. METHODS: Data of 92 children (52 girls, 40 boys) aged 6 to 36 months were obtained. Sleep habits as well as positive and negative emotions were monitored by educators during nursery times through a sleep and emotion diary for two weeks. RESULTS: Explorative analyses showed that diurnal sleep hours decreased across age groups (except for females aged 25-36 months) and that all age groups had a lower amount of nocturnal sleep than is recommended by the National Sleep Foundation. Partial correlation analysis showed significant correlation between daytime sleep onset latency and positive emotions. Mediation analyses showed that daytime napping is relevant for emotional functioning independently of nocturnal sleep quality. CONCLUSIONS: Daytime sleep in early childhood seems to be linked to the management of positive and negative emotions and could play a role in healthy development of emotional processes.

The efficacy of cognitive and behavior therapies for insomnia on daytime symptoms: A systematic review and network meta-analysis.

Insomnia disorder, defined by nocturnal and daytime symptoms, is highly prevalent worldwide and is associated with the onset of mental illness. Although daytime symptoms are often the reason insomnia patients seek help, it is not clear whether recommended treatment is effective on daytime symptoms. We aimed to investigate the efficacy of cognitive and behavior therapies for insomnia (CBT-I) on all daytime symptoms explored in the literature using both direct and indirect data. 86 studies (15,578 participants) met inclusion criteria. Results showed significant effects of CBT-I administered face-to-face individually, in group and different self-help settings on depressive symptoms, anxiety, daytime sleepiness, fatigue, quality of life, daytime and social functioning and mental state, with Cohen's d's ranging from -0.52 and 0.81. Our results suggest that CBT-I is effective in the treatment of daytime symptoms, albeit with predominantly small to moderate effects compared to far stronger effects on the core symptoms of insomnia. Effects may be biased for depressive and anxiety symptoms, since many included studies excluded patients with severe levels of these complaints. Further, small to moderate effects may reflect that CBT-I, by improving nighttime symptoms, has a positive effect on daytime symptoms, but it does not target the daytime symptoms directly. Future studies may benefit from adding therapeutic techniques that address daytime symptoms more directly.

Dreaming and Insomnia: Link between Physiological REM Parameters and Mentation Characteristics.

(1) Background: An unresolved phenomenon of insomnia disorder is a discrepancy between objectively measured sleep and subjective complaints. It has been shown that rapid eye movement (REM) sleep might be especially vulnerable to an altered perception. The present work aimed to investigate the link between physiological REM parameters and mentation characteristics in REM sleep. (2) Methods: 22 patients with insomnia and 23 good sleepers indicating at least one REM mentation within an awakening study were included. Multivariate analyses of variance (MANOVAs) were calculated to examine group differences and effects of mentation characteristics on number of arousals, REM density, and spectral power prior to awakenings. (3) Results: Increased perceived wakefulness was related to lower delta, theta, and alpha power in the minute prior to the REM awakenings. Nevertheless, no group differences regarding spectral power were found. With respect to number of arousals and REM density, no significant effects of mentation characteristics and no group differences were found. (4) Conclusions: Our results suggest that spectral power in REM sleep is linked with altered sleep perception. Reduced delta, theta, and alpha power might be a signature of this modified REM sleep associated with a high level of perceived wakefulness. Future awakening studies are necessary to further explore the link between physiological REM parameters and sleep perception.

A Systematic Review and Network Meta-Analysis of Randomized Controlled Trials Evaluating the Evidence Base of Melatonin, Light Exposure, Exercise, and Complementary and Alternative Medicine for Patients with Insomnia Disorder.

Insomnia is a prevalent disorder and it leads to relevant impairment in health-related quality of life. Recent clinical guidelines pointed out that Cognitive-Behavior Therapy for Insomnia (CBT-I) should be considered as first-line intervention. Nevertheless, many other interventions are commonly used by patients or have been proposed as effective for insomnia. These include melatonin, light exposure, exercise, and complementary and alternative medicine. Evaluation of comparable effectiveness of these interventions with first-line intervention for insomnia is however still lacking. We conducted a systematic review and network meta-analysis on the effects of these interventions. PubMed, PsycInfo, PsycArticles, MEDLINE, and CINAHL were systematically searched and 40 studies were included in the systematic review, while 36 were entered into the meta-analysis. Eight network meta-analyses were conducted. Findings support effectiveness of melatonin in improving sleep-onset difficulties and of meditative movement therapies for self-report sleep efficiency and severity of the insomnia disorder. Some support was observed for exercise, hypnotherapy, and transcranial magnetic resonance, but the number of studies for these interventions is still too small. None of the considered interventions received superior evidence to CBT-I, which should be more widely disseminated in primary care.