An examination of the etiologic overlap between the genetic and environmental influences on insomnia and common psychopathology

Examining the connection between weekend catch-up sleep and depression: Insights from 2017 to 2020 NHANES information

BACKGROUND

Depression, a prevalent mental disorder, has shown an increasing trend in recent years, imposing a significant burden on health and society. Adequate sleep has been proven to reduce the incidence of depression. This study seeks to explore how Weekend Catch-up Sleep (WCS) is connected with the prevalence of depression in the American population.

METHODS

The National Health and Nutrition Examination Survey (NHANES) provides representative data for the U.S.

POPULATION

We utilized data from the 2017-2018 and 2019-2020 cycles. Depression was operationally defined as a PHQ-9 score exceeding 10. WCS duration was categorized into five groups: no change in sleep duration (=0 h), decreased sleep duration (<0), short catch-up sleep duration (>0 h, ≤1 h), moderate catch-up sleep duration (>1 h, <2 h), and long catch-up sleep duration (≥2 h).

RESULTS

Among the 8039 individuals, the distribution of WCS duration was as follows: no change (WCS = 0 h) in 2999 individuals (37.3 %), decreased sleep (WCS < 0 h) in 1199 individuals (14.9 %), short catch-up sleep (0 h < WCS ≤ 1 h) in 1602 individuals (19.9 %), moderate catch-up sleep (1 h < WCS < 2 h) in 479 individuals (6.0 %), and long catch-up sleep (WCS ≥ 2 h) in 1760 individuals (21.9 %). Acting by adjustment for all covariates in a multiple regression analysis, we discovered that persons with 1 to 2 h of weekend catch-up sleep had a substantially low prevalence of depression concerning those with WCS = 0 (OR 0.22, 95 % CI 0.08-0.59, P = 0.007).

CONCLUSION

The prevalence of depression in individuals engaging in weekend catch-up sleep for 1 to 2 h is lower than those who do not catch up on weekends. This discovery on the treatment and prevention of depression provides a new perspective. However, further prospective research and clinical trials are needed for a comprehensive investigation.

Clinical effectiveness of internet-based cognitive behavioral therapy for insomnia in routine secondary care: results of a randomized controlled trial

Introduction

Delivering cognitive behavioral therapy for insomnia over the internet bears the advantage of accessibility and uptake to many patients suffering from chronic insomnia. In the current study, we aimed to investigate the effectiveness of internet-based cognitive behavioral therapy for insomnia (iCBT-I) in routine care.

Materials and methods

We conducted a two-arm non-blinded randomized controlled trial with care as usual (CAU) as a control condition. Participants were recruited in a specialized outpatient sleep medicine department. Both arms had access to other healthcare resources, and the intervention group had access to the iCBT-I program for 2 months. The primary outcome was insomnia severity, measured by the Insomnia Severity Index (ISI). Secondary outcomes were fatigue severity, daytime sleepiness, affective symptoms, dysfunctional beliefs and attitudes about sleep, sleep locus of control, sleep hygiene, sleep efficiency (SE), sleep onset latency, wake time after sleep onset (WASO), and total sleep time (TST). Linear mixed models for repeated measures were used to analyze the longitudinal data at baseline, post-treatment, and after 3 months of follow-up. The trial was registered at www.clinicaltrials.gov (NCT04300218 21.04.2020).

Results

The results showed a significant time*group interaction effect (p = 0.001) at post-treatment with between-group effect size (d = 0.51), indicating that the ISI decreased by a score of 3.8-fold in the iCBT-I group than in the CAU group. There was no significant difference in ISI between groups at follow-up. Regarding secondary outcomes, dysfunctional beliefs about sleep, SE, and WASO decreased significantly during treatment in the intervention group with between-group effect sizes d = 0.35, d = -0.51, and d = 0.47, respectively. At the follow-up, between-group effects on DBAS and SE remained significant: d = 0.36 and d = -0.63, respectively. For TST, we observed a significant time*group effect of d = -0.38 only after follow-up.

Conclusion

Our findings suggest that iCBT-I has a significant effect on insomnia severity at post-treatment compared to CAU. iCBT-I further improved dysfunctional beliefs about sleep and improved subjective sleep characteristics, such as SE, WASO, and TST during 3 months after treatment.

Clinical trial registration

www.clinicaltrials.gov, identifier (NCT04300218).

Associations between insomnia symptoms and inflammatory cytokines in adolescents with first-episode and recurrent major depressive disorder

BACKGROUND

Insomnia symptoms are often associated with increased levels of inflammatory biomarkers. However, such associations have not been adequately explored in adolescents with major depressive disorder (MDD). This study aimed to examine the associations between insomnia symptoms with inflammatory cytokines in adolescents with first-episode and recurrent MDD.

METHODS

From January to December 2021, this study included 164 adolescents with MDD and 76 healthy controls (HCs). The Center for Epidemiological Studies Depression Scale (CES-D) and the Insomnia Severity Index Scale (ISI) were used to assess depressive and insomnia symptoms, respectively. Also, plasma levels of interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-17 A and tumor necrosis factor-α (TNF-α) were measured.

RESULTS

The prevalence of mild, moderate and severe insomnia in adolescents with MDD was 40.24 %, 36.59 % and 6.71 %, respectively. The patients had higher levels of IL-1β, IL-6 and TNF-α than HCs (all p < 0.05). ISI score was positively correlated with CES-D score and levels of IL-1β, IL-6 and TNF-α in first-episode patients but not in recurrent patients. A further multivariate stepwise linear regression analysis showed that ISI score was independently associated with CES-D score (beta = 0.523, t = 5.833, p < 0.001) and TNF-α levels (beta = 0.254, t = 2.832, p = 0.006).

LIMITATIONS

The cross-sectional design leads to failure to make causal inferences.

CONCLUSION

Insomnia symptoms are common in adolescents with MDD and associated with elevated levels of inflammatory cytokines in first-episode patients. The findings suggest that inflammatory cytokines may relate to the pathogenesis of insomnia symptoms in adolescents with MDD, but further longitudinal studies are needed to explore the causal association between insomnia symptoms and inflammatory cytokines in MDD.

Linking repetitive negative thinking and insomnia symptoms: A longitudinal trait-state model

Sleep disturbance is highly debilitating, and an abundance of research suggests that repetitive negative thinking (i.e., rumination, worry) may contribute to the development and maintenance of maladaptive sleep patterns, such as insomnia symptoms. Although repetitive negative thinking is often conceptualized as a 'trait' risk factor for anxiety-related disorders, it is unclear if it consists of time-varying (TV) or state-like features versus time-invariant (TI) or trait-like characteristics. Furthermore, it is unclear if it is the TV or TI components of repetitive negative thinking that contribute to insomnia symptoms that is commonly observed in anxiety-related disorders. In a 6-wave, 5-month longitudinal study, community participants (N = 1219) completed measures of rumination, worry, transdiagnostic repetitive negative thinking, and insomnia symptoms. A latent variable (trait-state-occasion) model was applied to the measures of repetitive negative thinking. The results showed that although estimates of TI factor variance and TV factor variance were both significant for latent repetitive negative thinking, worry, and rumination, the proportion of TI factor variance (0.82-0.89) was greater than the amount of TV factor variance (0.11-0.19). Although TV factor stability was statistically significant for latent repetitive negative thinking, rumination, and worry, the magnitude of the coefficients was small. Furthermore, regression weights for the latent repetitive negative thinking, rumination, and worry TI factor were significant and larger than those for the TV factor in predicting insomnia symptoms at each of the six time points. These findings suggest that repetitive negative thinking is largely TI, and it is this TI component that contributes to insomnia symptoms. Implications for conceptualizations of repetitive negative thinking as a predisposing and perpetuating factor in insomnia for anxiety and related disorders are discussed.

Sleep disturbances and depression are bidirectionally associated among college student athletes across COVID-19 pandemic exposure classes

College athletes may be vulnerable to sleep disturbances and depression during the COVID-19 pandemic as a result of large shifts in social and athletic obligations. In a national sample of college athletes, we examined the associations between sleep disturbances and depression across two timepoints, using COVID-19 exposure as a moderator. Data were collected from 2098 NCAA Division I, II, and III college athletes during two timepoints, from April 10 to May 23, and from August 4 to September 15, 2020. First, a latent class analysis was conducted with five indicators of levels of COVID-19 exposure to determine different exposure profiles. Second, to examine the directionality of associations between sleep disturbance and depression, a cross-lagged panel model was added to the latent class membership structural equation model; this allowed for testing of moderation by COVID exposure class membership. Four highly homogeneous, well-separated classes of COVID-19 exposure were enumerated: Low Exposure (57%); Quarantine Only (21%); High Other, Low Self Exposure (14%); and High Exposure (8%). COVID-19 exposure class membership did not significantly moderate associations between sleep disturbances and depression. However, student athletes significantly differed in T2 depression by their COVID-19 exposure class membership. Depression and sleep disturbances were positively correlated at both timepoints (r _T1 = 0.39; r _T2 = 0.30). Additionally, cross-lagged associations were found such that T2 depression was associated with T1 sleep disturbances (β = 0.14) and vice versa (β = 0.11). These cross-lagged associations were not significantly affected by athletes' level of COVID-19 exposure during the beginning of the pandemic.

Relationship between antenatal sleep quality and depression in perinatal women: A comprehensive meta-analysis of observational studies

BACKGROUND

Perinatal depression is a global mental health problem. Studies have suggested that perinatal depression is related to poor sleep quality during pregnancy. However, evidence on the influence and mechanism of sleep quality on the risk of developing perinatal depression remains limited and inconclusive.

METHODS

A systematic review was conducted in PubMed, Web of Science, Embase, CINAHI and Cochrane Library for relevant original quantitative studies published in English. A hand search of the reference list of relevant studies was also performed. Meta-analysis was performed using RevMan software and a random-effects model. Potential heterogeneity source was explored by subgroup and sensitivity analyses, and potential publication bias was tested using funnel plots and Begg's test.

RESULTS

A total of ten studies involving 39,574 participants were included in our meta-analysis. Overall, women who experienced poor sleep quality during pregnancy were at a significantly higher risk of developing depression, with antenatal depression 3.72 times higher, postpartum depression 2.71 times higher, and perinatal depression 3.46 times higher, compared to those did not experience poor sleep quality.

LIMITATIONS

Different measuring tools and unobserved confounding factors may make some bias in our result. What's more, not all included studies were initially designed to assess the association between antenatal sleep quality and the risk of developing perinatal depression.

CONCLUSION

Our meta-analysis found that antenatal sleep quality was negatively associated with the risk for perinatal depression. Our findings highlight the importance of improving sleep quality during pregnancy for mental health among perinatal women.

Insomnia and treatment-resistant depression

Depression and sleep disturbance are related closely with bidirectional relationship. The heterogenic diagnostic criteria of major depressive disorder composed by the myriad combination of symptoms including sleep disturbance. Insomnia is an identifiable risk factor for depression and the treatment of insomnia might be able to prevent subsequent major depressive episodes which draws psychiatrists' attention to the interface of psychiatry and sleep medicine field. It is important to identify occult sleep disturbance in patients with treatment-resistant depression to improve treatment outcome. New tools to objectively measure sleep at home environment represent a great march in clinical care and research modalities but need further validation before they can be applying widespread at sleep and depression intersection. Careful evaluation and measurement of the phenotype and nature of sleep disturbance will continue to advance understanding of the biological bases of psychiatric disorders and the connections with sleep.

Behaviour genetics and sleep: A narrative review of the last decade of quantitative and molecular genetic research in humans

During the last decade quantitative and molecular genetic research on sleep has increased considerably. New behavioural genetics techniques have marked a new era for sleep research. This paper provides a summary of the most important findings from the last ten years, on the genetic and environmental influences on sleep and sleep disorders and their associations with health-related variables (including anxiety and depression) in humans. In this review we present a brief summary of the main methods in behaviour genetic research (such as twin and genome-wide association studies). We then discuss key research findings on: genetic and environmental influences on normal sleep and sleep disorders, as well as on the association between sleep and health variables (highlighting a substantial role for genes in individual differences in sleep and their associations with other variables). We end by discussing future lines of enquiry and drawing conclusions, including those focused on problems and misconceptions associated with research of this type. In this last decade our knowledge about genetic and environmental influences on sleep and its disorders has expanded. Both, twin and genome-wide association studies show that sleep and sleep disorders are substantially influenced by genetic factors and for the very first time multiple specific genetic variants have been associated with sleep traits and disorders.

Shared and differential fractional amplitude of low-frequency fluctuation patterns at rest in major depressive disorders with or without sleep disturbance

Objective

Sleep disturbances (SD) are commonly found in patients with major depressive disorder (MDD). This study aims to explore the influence of SD symptoms on clinical characteristics in patients with MDD and to investigate the shared and distinct fractional amplitude of low-frequency fluctuation (fALFF) patterns in these patients with or without SD symptoms.

Methods

Twenty-four MDD patients with SD symptoms (Pa_s), 33 MDD patients without SD symptoms (Pa_ns) and 32 healthy controls (HCs) were included in this study. The fALFF and correlation analyses were applied to analyze the features of imaging and clinical data.

Results

Pa_s showed more severe anxiety and depression than Pa_ns. Compared with Pa_ns, Pa_s exhibited increased fALFF value in the left precuneus. Patients shared abnormal fALFF in the frontal-occipital brain regions. There was a positive correlation between fALFF values of the left precuneus and sleep disturbance scores (r = 0.607, p = 0.0000056734) in all patients in addition to a negative correlation between fALFF values of the left MOG/cuneus and HAMD-17 total scores (r = -0.595, p = 0.002141) in Pa_s. The receiver operating characteristic (ROC) results of the fALFF could be used to discriminate Pa_s from Pa_ns with a specificity of 72.73% and a sensitivity of 70.83%.

Conclusion

Pa_s displayed more serious anxiety and depression symptoms. Patients shared abnormal fALFF in the frontal-occipital brain regions, which may be a common characteristic for MDD. And increased fALFF value in the left precuneus might be a specific neuroimaging feature of MDD patients with SD symptoms.

Physical inactivity amplifies the negative association between sleep quality and depressive symptoms

Poor sleep quality and physical inactivity are known risk factors for depressive symptoms. Yet, whether these factors differently contribute to depressive symptoms and whether they interact with one another remains unclear. Here, we examined how sleep quality and physical activity influence depressive symptoms in 79,274 adults 50 years of age or older (52.4% women) from the Survey of Health, Aging and Retirement in Europe (SHARE) study. Sleep quality (poor vs. good), physical activity (inactive vs. active), and depressive symptoms (0 to 12 score) were repeatedly collected (7 waves of data collection) between 2004 and 2017. Results showed that sleep quality and physical activity were associated with depressive symptoms. Specifically, participants with poorer sleep quality reported more depressive symptoms than participants with better sleep quality (b = 1.85, 95% CI = 1.83-1.86, p < .001). Likewise, compared to physically active participants, physically inactive participants reported more depressive symptoms (b = 0.44, 95% CI = 0.42-0.45, p < .001). Moreover, sleep quality and physical activity showed an interactive association with depressive symptoms (b = 0.17, 95% CI = 0.13-0.20, p < .001). The negative association between poor sleep quality and higher depressive symptoms was stronger in physically inactive than active participants. These findings suggest that, in adults 50 years of age or older, both poor sleep quality and physical inactivity are related to an increase in depressive symptoms. Moreover, the detrimental association between poor sleep quality and depressive symptoms is amplified in physically inactive individuals.

Etiological links between autism and difficulties in initiating and maintaining sleep: a familial co-aggregation and twin study

BACKGROUND

Difficulties initiating and maintaining sleep (DIMS) are frequent features of autism, yet little is known about why these conditions co-occur. One possibility is that they share etiological factors, yet this hypothesis remains to be tested using quantitative genetic designs. We thus investigated etiological links between autism and DIMS using familial co-aggregation and twin methods.

METHODS

Twins, siblings, half-siblings, and cousins of 50,097 individuals with autism were identified from Swedish population registries. Their risk of DIMS, defined through diagnoses of insomnia and/or melatonin prescriptions, was then estimated. Twin analyses conducted on 15,279 child and adolescent twin pairs investigated etiological links between DIMS and ASD.

RESULTS

22.8% of autistic individuals had DIMS. Monozygotic co-twins of individuals with autism were most at risk of DIMS compared to the reference group (OR = 6.6 [2.5-17.4]), followed by dizygotic co-twins (OR = 2.6 [1.5-4.5]) and full siblings (OR = 2.5 [2.4-2.6]). Half-siblings and cousins of individuals with autism were least likely to have DIMS relative to the reference group (OR range = 1.3-1.5). Twin analyses estimated a correlation of 0.57 (0.53-0.61) between autism and DIMS, with a genetic correlation of 0.62 (0.60-0.68). These overlapping genetic factors explained 94% of the covariance between these conditions. Autistic traits also showed genetic overlap with DIMS.

CONCLUSIONS

Our results suggest that shared genetic mechanisms underlie autism and DIMS, which may lead them to co-occur. Untangling the etiological overlap between these conditions has potential to assist in understanding the etiology of each condition, as well as their associated outcomes.

Prevalence of insomnia symptoms and associated risk factors in UK Biobank participants with hazardous alcohol use and major depression

INTRODUCTION

We aimed to examine the prevalence of insomnia symptoms (IS), sleep duration, and associated risk factors in participants with hazardous/harmful alcohol use (HAU), major depressive disorders (MDD), and HAU+MDD.

METHODS

Data from the UK Biobank (UKB) (n = 55,000) were utilized to categorize participants into those with MDD (n = 5612), HAU (n = 15,893), MDD+HAU (n = 3738), and controls (n = 29,511). We examined whether rates of IS and sleep duration differed among the groups and determined the clinical predictors of IS. Rates of IS and sleep duration were compared using regression analyses accounting for demographic (age, sex, ethnicity, Townsend deprivation index) and clinical (body mass index, neuroticism score, alcohol consumption) factors.

RESULTS

The unadjusted prevalence of IS was 26.5%, 27%, 39.5%, and 43% in control, HAU, MDD, and MDD+HAU categories respectively. Rates of IS in controls versus HAU and MDD versus MDD+HAU did not differ in unadjusted models (p = 0.45 and 0.075, respectively). Prevalence of IS differed in the four groups (p < 0.0001 for all pairwise comparisons) after adjusting for demographic confounders. After further adjustment for clinical factors, effect sizes were reduced, but pairwise comparisons remained significant. After adjusting for demographic and clinical factors, sleep duration did not differ among the groups. After accounting for diagnostic category and demographic/clinical factors, older age (OR=1.33 per 10 year increase; p < 0.0001), female sex (OR=1.39; p < 0.0001), obesity (OR=1.17 compared to normal; p < 0.0001), higher neuroticism score (OR=1.13; p < 0.0001), and alcohol consumption (OR=1.01 per serving increase; p < 0.0001) were associated with IS.

CONCLUSION

Sleep-related morbidity is the greatest in the MDD+HAU group, followed by the MDD group. Demographic and clinical characteristics explain some, but not all of the differences in the prevalence of IS in MDD±HAU. Genetic and other factors capable of influencing IS in those with MDD, HAU, and MDD+HAU merit future investigation.

The Evolving Nexus of Sleep and Depression

Sleep disturbances and depression are closely linked and share a bidirectional relationship. These interconnections can inform the pathophysiology underlying each condition. Insomnia is an established and modifiable risk factor for depression, the treatment of which offers the critical opportunity to prevent major depressive episodes, a paradigm-shifting model for psychiatry. Identification of occult sleep disorders may also improve outcomes in treatment-resistant depression. Sleep alterations and manipulations may additionally clarify the mechanisms that underlie rapid-acting antidepressant therapies. Both sleep disturbance and depression are heterogeneous processes, and evolving standards in psychiatric research that consider the transdiagnostic components of each are more likely to lead to translational progress at their nexus. Emerging tools to objectively quantify sleep and its disturbances in the home environment offer great potential to advance clinical care and research, but nascent technologies require further advances and validation prior to widespread application at the interface of sleep and depression.

Assessing the causal associations of insomnia with depressive symptoms and subjective well-being: a bidirectional Mendelian randomization study

BACKGROUND

The interactions and associations between insomnia, depressive symptoms, and subjective well-being are complex, thus it is hard to explore the effect and direction of causalities. This bidirectional Mendelian randomization (MR) study was to assess the causal associations of insomnia with depressive symptoms and subjective well-being.

METHODS

Summary statistics for insomnia, depressive symptoms, and subjective well-being were obtained from three large-scale genome-wide association studies (GWAS) of European ancestry. MR analyses were mainly conducted with the inverse-variance-weighted (IVW) method. The weighted-median method, MR-Egger method, and MR-Pleiotropy RESidual Sum and Outlier (PRESSO) test were adopted to test whether the estimates were robust. The adjusted MR analysis was performed to avoid the effect of potential pleiotropy.

RESULTS

There was evidence to support a causal association between genetically predicted insomnia and depressive symptoms (beta (β) = 0.086, 95% confidence interval (CI) = 0.068 to 0.104, P = 8.6E-21). Meanwhile, genetically predicted depressive symptoms was associated with a higher risk of insomnia (β = 0.543, 95% CI = 0.331 to 0.754, P = 4.8E-07). Genetically predicted insomnia was negatively associated with subjective well-being (β = -0.043, 95% CI = -0.063 to -0.024, P = 1.2E-05). There was evidence of reverse causality between insomnia and subjective well-being (β = -0.821, 95% CI = -1.012 to -0.630, P = 4.0E-17).

CONCLUSIONS

MR analysis indicates bidirectional causal associations of insomnia with depressive symptoms and subjective well-being. People should give serious attention to and attempt to resolve the problems of insomnia, depressive symptoms, and subjective well-being, whichever comes first.

[On the question of a primary and secondary origin of insomnia]

Approximately 30% insomnia patients have associated somatic, neurological and psychiatric conditions. Clinician has to define causality of these conditions to determine a treatment plan. Secondary insomnia can result from the symptoms of a primary condition or form an impairment of central nervous system due to neurological disorder. Some associated conditions are characterized by high coincidence with insomnia, similar triggers and crossing genotype, neurophysiological and functional findings. This association with insomnia is observed in anxiety disorders, depression, chronic pain syndromes. The paper presents a concept of comorbid insomnia disorder which proposes the existence of a common neural structure which when affected causes the symptoms of both insomnia and comorbid disorder. Comorbid disorders can also be interconnected due to the overlap of the responsible nerve centers. Positive effect of specific pharmacological, psychotherapeutical and behavioral treatment on both conditions evidences this concept.

Molecular genetic overlap between posttraumatic stress disorder and sleep phenotypes

STUDY OBJECTIVES

Sleep problems are common, serving as both a predictor and symptom of posttraumatic stress disorder (PTSD), with these bidirectional relationships well established in the literature. While both sleep phenotypes and PTSD are moderately heritable, there has been a paucity of investigation into potential genetic overlap between sleep and PTSD. Here, we estimate genetic correlations between multiple sleep phenotypes (including insomnia symptoms, sleep duration, daytime sleepiness, and chronotype) and PTSD, using results from the largest genome-wide association study (GWAS) to date of PTSD, as well as publicly available GWAS results for sleep phenotypes within UK Biobank data (23 variations, encompassing four main phenotypes).

METHODS

Genetic correlations were estimated utilizing linkage disequilibrium score regression (LDSC), an approach that uses GWAS summary statistics to compute genetic correlations across traits, and Mendelian randomization (MR) analyses were conducted to follow up on significant correlations.

RESULTS

Significant, moderate genetic correlations were found between insomnia symptoms (rg range 0.36-0.49), oversleeping (rg range 0.32-0.44), undersleeping (rg range 0.48-0.49), and PTSD. In contrast, there were mixed results for continuous sleep duration and daytime sleepiness phenotypes, and chronotype was not correlated with PTSD. MR analyses did not provide evidence for casual effects of sleep phenotypes on PTSD.

CONCLUSION

Sleep phenotypes, particularly insomnia symptoms and extremes of sleep duration, have shared genetic etiology with PTSD, but causal relationships were not identified. This highlights the importance of further investigation into the overlapping influences on these phenotypes as sample sizes increase and new methods to investigate directionality and causality become available.

Circadian depression: A mood disorder phenotype

Major mood syndromes are among the most common and disabling mental disorders. However, a lack of clear delineation of their underlying pathophysiological mechanisms is a major barrier to prevention and optimised treatments. Dysfunction of the 24-h circadian system is a candidate mechanism that has genetic, behavioural, and neurobiological links to mood syndromes. Here, we outline evidence for a new clinical phenotype, which we have called 'circadian depression'. We propose that key clinical characteristics of circadian depression include disrupted 24-h sleep-wake cycles, reduced motor activity, low subjective energy, and weight gain. The illness course includes early age-of-onset, phenomena suggestive of bipolarity (defined by bidirectional associations between objective motor and subjective energy/mood states), poor response to conventional antidepressant medications, and concurrent cardiometabolic and inflammatory disturbances. Identifying this phenotype could be clinically valuable, as circadian-targeted strategies show promise for reducing depressive symptoms and stabilising illness course. Further investigation of underlying circadian disturbances in mood syndromes is needed to evaluate the clinical utility of this phenotype and guide the optimal use of circadian-targeted interventions.

Cognitive behavioural therapy for insomnia for patients with co-morbid generalized anxiety disorder: an open trial on clinical outcomes and putative mechanisms

BACKGROUND

Very little is known concerning the efficacy of psychosocial treatments for patients with insomnia disorder co-morbid with generalized anxiety disorder (GAD).

AIM

The aim was to examine the efficacy of cognitive behavioral therapy for insomnia (CBT-I) for patients with insomnia disorder co-morbid with GAD.

METHOD

Given the limited, previous research on therapies for patients with insomnia disorder co-morbid with GAD, an open trial design was used. Twenty-four patients with insomnia disorder and GAD were administered CBT-I across 10 weeks. Across the study period to 6 months follow-up, the participants completed measures indexing insomnia, anxiety, worry, depression, functional impairment, quality of life, treatment perception (credibility, expectancy and satisfaction), adverse events and putative mechanisms.

RESULTS

Moderate to large effect sizes for CBT-I were observed for insomnia symptoms. In terms of insomnia severity, approximately 61% of the patients responded to CBT-I and 26-48% remitted. Moderate to large effect sizes were also demonstrated for GAD symptoms, depression, functional impairment and quality of life. Roughly one-third of the participants reported an adverse event during CBT-I. Five of the seven putative mechanisms were significantly reversed in the expected direction, i.e. all four cognitive process measures and time in bed.

CONCLUSIONS

This open trial indicates that CBT-I is an efficacious intervention for patients with insomnia disorder co-morbid with GAD. The results highlight the need for further research using a randomized controlled trial design with analyses of mechanisms of change.

The heritability of insomnia: Systematic review and meta-analysis of twin studies

Twin studies have consistently found that genetic factors explain a substantial proportion of the variance for insomnia. However, studies vary widely in their heritability estimates. Therefore, this meta-analysis aimed to: 1) Estimate the mean heritability of insomnia; 2) Assess heterogeneity among twin studies of insomnia; and 3) Search and analyse characteristics of the studies (moderator variables) that may explain heterogeneity among estimates. For this purpose, separate meta-analyses were carried out for MZ and DZ correlations and for heritability estimates by assuming random-effects models. Thirteen independent samples were included in this meta-analysis. The heterogeneity index for heritability estimates was significant in both best fitting models (I² = 98.77, P < .0001) and full models (I² = 97.80, P < .0001). MZ correlations were higher (0.37; 95%CI: 0.31,.43) than DZ correlations (0.15; 95%CI: 0.12,.18). A mean heritability of 0.39 (95%CI: 0.32,.44) was found for insomnia. These results highlight the role of genetic factors in explaining differences among the population on insomnia and Emphasize heterogeneity among studies. Further research is needed to identify variables that could explain this heterogeneity.

The relationship between insomnia and the intensity of drinking in treatment-seeking individuals with alcohol dependence

BACKGROUND

Although insomnia is highly prevalent in alcohol use disorders(AUD), its associations with the severity of alcohol use, pre-existing psychiatric comorbidities and psychosocial problems are understudied. The present study evaluates the interplay between these factors using a structural equation model (SEM).

METHODS

We assessed baseline cross-sectional data on patients with AUD (N = 123) recruited to a placebo-controlled medication trial. Severity of alcohol use was measured by the Brief Michigan Alcoholism Screening Test (B-MAST). Insomnia Severity Index was used to assess insomnia symptoms. The Hamilton scales for Depression and Anxiety, Short Index of Problems and Timeline Follow Back evaluated psychiatric symptoms, psychosocial consequences of drinking and level of alcohol consumption respectively. We used logistic regression to evaluate the association between insomnia and severity of alcohol use while controlling for covariates. We constructed a SEM with observed variables to delineate the effect of psychiatric symptoms, psychosocial factors and current alcohol use on the pathway between alcohol use severity and insomnia.

RESULTS

The sample was predominately male(83.9 %), Black(54.6 %) and employed(60.0 %). About 45 % of the participants reported moderate-severe insomnia.The association between insomnia and B-MAST attenuated after adjustment for demographics, psychiatric symptoms and psychosocial problems(OR[95 % CI] = 1.17(0.99-1.47). SEM findings demonstrated that B-MAST and insomnia were linked to psychiatric symptoms (95 % Asymptotic-Confidence Interval (ACI): 0.015-0.159, p < 0.05) but not to psychosocial problems or current alcohol use.

CONCLUSION

Among treatment-seeking patients with AUD, psychiatric burden mediated the relationship between severity of alcohol use and insomnia. Clinicians should screen for underlying psychiatric disorders among treatment-seeking patients with AUD complaining of insomnia.

Sleep disturbance and psychiatric disorders

Signs of mental ill health that cut across psychiatric diagnostic categories at high rates are typically viewed as non-specific occurrences, downgraded in importance and disregarded. However, problems not associated with particular diagnoses should be expected if there is shared causation across mental health conditions. If dynamic networks of interacting symptoms are the reality of mental health presentations, then particularly disruptive and highly connected problems should be especially common. The non-specific occurrence might be highly consequential. One non-specific occurrence that is often overlooked is patients' chronic difficulty in getting good sleep. In this Review, we consider whether disrupted sleep might be a contributory causal factor in the occurrence of major types of mental health disorders. It is argued that insomnia and other mental health conditions not only share common causes but also show a bidirectional relationship, with typically the strongest pathway being disrupted sleep as a causal factor in the occurrence of other psychiatric problems. Treating insomnia lessens other mental health problems. Intervening on sleep at an early stage might be a preventive strategy for the onset of clinical disorders. Our recommendations are that insomnia is assessed routinely in the occurrence of mental health disorders; that sleep disturbance is treated in services as a problem in its own right, yet also recognised as a pathway to reduce other mental health difficulties; and that access to evidence-based treatment for sleep difficulties is expanded in mental health services.

Sleep quality and chronic neck pain: a cotwin study

STUDY OBJECTIVES

Sleep quality and chronic neck pain (NP) are associated. However, the genetic influences on this association have not been explored. This study investigated the genetic and environmental influences on the association between sleep quality and chronic NP.

METHODS

The sample comprised 2,328 individual twins from the Murcia Twin Registry (Spain). A bidirectional cotwin logistic regression analysis was performed (sleep quality assessed as the exposure and chronic NP as the outcome and vice versa). Analysis included 2 sequential stages: total sample analysis and within-pair twin case-control analysis.

RESULTS

Sleep quality was significantly associated with chronic NP in the total sample analysis (adjusted odds ratio [OR]: 1.09; 95% confidence interval [CI]: 1.06, 1.12; P < .001); in the cotwin case-control analysis, including both monozygotic and dizygotic twin pairs (adjusted OR: 1.10; 95% CI: 1.04, 1.17; P = .001); in dizygotic pairs (Adjusted OR: 1.11; 95% CI: 1.03, 1.19; P = .005); but not in monozygotic pairs (adjusted OR: 1.08; 95% CI: 0.98, 1.19; P = .118). Chronic NP was significantly associated with poor sleep quality in the total sample analysis (adjusted OR: 1.80; 95% CI: 1.43, 2.26; P < .001); in the cotwin case-control analysis, including both monozygotic and dizygotic twin pairs (Adjusted OR: 1.63; 95% CI: 1.07, 2.47; P = .023); in dizygotic pairs (Adjusted OR: 1.80; 95% CI: 1.05, 3.09; P = .031), but not in monozygotic pairs (adjusted OR: 1.67; 95% CI: 0.80, 3.48; P = .170).

CONCLUSIONS

The association between sleep quality and chronic NP is partially confounded by genetic factors.

Insomnia and posttraumatic stress symptoms: Evidence of shared etiology

Posttraumatic stress disorder (PTSD) and insomnia are comorbid clinical conditions that are thought to result from genetic and environmental effects. Though studies have established the heritability of these disorders independently, no study to date has examined the genetic contributions to the relation between insomnia and PTSD symptoms (PTSS). The present study assessed this gap in the literature using a behavioral genetics approach to symptom dimensions. The sample consisted of 242 twin pairs who endorsed lifetime trauma exposure. Insomnia symptoms were assessed with the Women's Health Initiative Survey, and intrusion and avoidance PTSS were assessed with the Impact of Events Scale. Structural equation modeling was then employed to test the relative contributions of genetic, shared environmental, and nonshared environmental components to the relations between insomnia symptoms and intrusions and avoidance. Results indicated a significant association between insomnia symptoms and intrusions (r = 0.33, p < 0.01) and insomnia symptoms and avoidance (r = 0.20, p < 0.01), and 36-44% of phenotypic variance was accounted for by genetic contributions. These findings highlight a significant role for genetic factors in the mechanisms underlying the comorbidity between insomnia and PTSS. The implications for current etiological models of PTSD and insomnia are discussed.

Sleep quality, insomnia, and internalizing difficulties in adolescents: insights from a twin study

Study Objectives

There is a well-established association between poor sleep quality and internalizing traits. This relationship has previously been studied using a twin design. However, when it comes to adolescence, there is a paucity of twin studies that have investigated this relationship, despite the importance of this developmental stage for both the development of poor sleep quality and internalizing symptoms. Additionally, anxiety sensitivity, which is commonly associated with poor sleep quality, has not been studied in this context. Our objective was to estimate genetic and environmental influences on the relationships between insomnia, poor sleep quality, and internalizing symptoms in adolescence.

Methods

Insomnia, poor sleep quality, depression, anxiety, and anxiety sensitivity traits were measured in a sample of 5111 twin pairs from the Twins Early Development Study, born between 1994 and 1996 (mean age 16.32 years [SD = 0.68]).

Results

A moderate proportion of the variance for the different variables (.29–.42) was explained by genetic factors. Associations between sleep and internalizing variables were moderate (r = .34–.46) and there was a large genetic overlap between these variables (rA= .51–.73).

Conclusion

This study adds novel information by showing that there are large genetic correlations between sleep disturbances and internalizing symptoms in adolescence.

Alcohol and sleep-related problems

Alcohol is one of the most commonly used psychoactive substances in the community. Many individuals use alcohol for its sleep-promoting effects. Nonetheless, alcohol disrupts sleep through multiple mechanisms, such as disrupting electrophysiologic sleep architecture, triggering insomnia, and contributing to abnormalities of circadian rhythms and short sleep duration (SSD) in cross-sectional studies. Alcohol also increases breathing-related sleep events such as snoring and oxygen desaturation, especially in those with pre-existing problems. Emerging data demonstrate that insomnia may co-exist with SSD and circadian abnormalities. Future studies should unravel these tentative associations in individuals who misuse alcohol.

REM sleep fragmentation associated with depressive symptoms and genetic risk for depression in a community-based sample of adolescents

INTRODUCTION

Fragmented REM sleep may impede overnight resolution of distress and increase depressive symptoms. Furthermore, both fragmented REM and depressive symptoms may share a common genetic factor. We explored the associations between REM sleep fragmentation, depressive symptoms, and a polygenic risk score (PRS) for depression among adolescents.

METHODS

About 161 adolescents (mean age 16.9 ± 0.1 years) from a birth cohort underwent a sleep EEG and completed the Beck Depression Inventory-II the same day. We calculated PRSes for depressive symptoms with PRSice 1.25 software using weights from a recent genome-wide association study for dimensions of depressive symptoms (negative emotion, lack of positive emotion and somatic complaints). REM fragmentation in relation to entire REM duration was manually calculated from all REM epochs. REM latency and density were derived using SomnoMedics DOMINO software.

RESULTS

PRSes for somatic complaints and lack of positive emotions were associated with higher REM fragmentation percent. A higher level of depressive symptoms was associated with increased percent of REM fragmentation and higher REM density, independently of the genetic risks. Belonging to the highest decile in depressive symptoms was associated with a 2.9- and 7.6-fold risk of belonging to the highest tertile in REM fragmentation and density. In addition, higher PRS for somatic complaints had an independent, additive effect on increased REM fragmentation.

LIMITATION

A single night's sleep EEG was measured, thus the night-to-night stability of the REM fragmentation-depressive symptom link is unclear.

CONCLUSION

Depressive symptoms and genetic risk score for somatic complaints are independently associated with more fragmented REM sleep. This offers new insights on the quality of sleep and its relation to adolescents' mood.

Depression in sleep disturbance: A review on a bidirectional relationship, mechanisms and treatment

Sleep disturbance is the most prominent symptom in depressive patients and was formerly regarded as a main secondary manifestation of depression. However, many longitudinal studies have identified insomnia as an independent risk factor for the development of emerging or recurrent depression among young, middle‐aged and older adults. This bidirectional association between sleep disturbance and depression has created a new perspective that sleep problems are no longer an epiphenomenon of depression but a predictive prodromal symptom. In this review, we highlight the treatment of sleep disturbance before, during and after depression, which probably plays an important role in improving outcomes and preventing the recurrence of depression. In clinical practice, pharmacological therapies, including hypnotics and antidepressants, and non‐pharmacological therapies are typically applied. A better understanding of the pathophysiological mechanisms between sleep disturbance and depression can help psychiatrists better manage this comorbidity.

Association Between Insomnia And Mortality Is Only Evident Among Long Sleepers

BACKGROUND

Previous studies investigating the relationship between insomnia and mortality have been inconsistent.

PURPOSE

We aimed to assess whether nocturnal insomnia symptoms and non-restorative sleep are associated with all-cause mortality and whether they modify the associations between short and long sleep duration and all-cause mortality.

PATIENTS AND METHODS

The present report is based on a prospective cohort study of 39,139 participants with a mean follow-up time of 19.6 years. Cox proportional hazard models with attained age as timescale were used to estimate overall mortality hazard ratios (HRs) with 95% confidence intervals (CI) for different categories of sleep duration and insomnia symptoms.

RESULTS

Both difficulty initiating sleep and daytime sleepiness were independently associated with increased mortality among those with sleep duration of 9 hrs or more (HR 1.51, 95% CI 1.11-2.07 and HR 1.37, 95% CI 1.03-1.82). Mortality increased with increasing severity of difficulties initiating sleep (p for trend 0.04) and daytime sleepiness (p for trend 0.01) among the long sleepers. None of the insomnia symptoms were associated with mortality among those who reported sleep duration of 8 hrs or less.

CONCLUSION

Long sleep in combination with difficulties initiating sleep and daytime sleepiness, possibly due to psychiatric or physical disorders, was thus associated with increased mortality, whereas long sleep without difficulties falling asleep or daytime sleepiness was not associated with mortality. Our study emphasizes the need to take nocturnal insomnia symptoms and daytime sleepiness into consideration when assessing the influence of sleep duration on mortality. Additional research is needed to elucidate the relationship between long sleep, insomnia and related psychiatric and physical disorders.

Efficacy and safety of herbal medicine (Bailemian capsule) for treating insomnia: Protocol for a systematic review and meta-analysis

BACKGROUND

Insomnia has become a universal subhealth disease, affecting more and more modern people's health and quality of life. At present, western medicine is only symptomatic treatment for insomnia. Bailemian Capsule (BLMC) is a proprietary Chinese medicine for treating insomnia. It has been widely used in China, but lacks evidence for evidence-based medicine. At the same time, the clinical efficacy and safety of BLMC are controversial. Therefore, the effectiveness and safety of BLMC in the treatment of insomnia are studied and systematically evaluated in this study. It provides reliable theoretical support for the treatment of insomnia with Traditional Chinese Medicine and the combination of traditional Chinese and Western medicine.

METHODS

The information was retrieved from electronic databases, Cochrane, PubMed, EMBASE, SinoMed, China National Knowledge Infrastructure, VIP Data, and WangFang Data. Randomized controlled trials on the BLMC in the treatment of insomnia were conducted. There was no limitation on the literature language. RevMan 5.3 software and STATA 12.0 software were used to perform the meta-analysis.

RESULTS

This review will be to assess the efficacy and safety of BLMC for insomnia.

CONCLUSION

Our systematic evaluation will provide evidence for the clinical efficacy and safety of BLMC in the treatment of insomnia, and will be published in the form of academic papers in the future to provide new ideas for clinicians in the treatment of insomnia.

Sleep, chronic pain, and opioid risk for apnea

Pain is an unwelcome sleep partner. Pain tends to erode sleep quality and alter the sleep restorative process in vulnerable patients. It can contribute to next-day sleepiness and fatigue, affecting cognitive function. Chronic pain and the use of opioid medications can also complicate the management of sleep disorders such as insomnia (difficulty falling and/or staying asleep) and sleep-disordered breathing (sleep apnea). Sleep problems can be related to various types of pain, including sleep headache (hypnic headache, cluster headache, migraine) and morning headache (transient tension type secondary to sleep apnea or to sleep bruxism or tooth grinding) as well as periodic limb movements (leg and arm dysesthesia with pain). Pain and sleep management strategies should be personalized to reflect the patient's history and ongoing complaints. Understanding the pain-sleep interaction requires assessments of: i) sleep quality, ii) potential contributions to fatigue, mood, and/or wake time functioning; iii) potential concomitant sleep-disordered breathing (SDB); and more importantly; iv) opioid use, as central apnea may occur in at-risk patients. Treatments include sleep hygiene advice, cognitive behavioral therapy, physical therapy, breathing devices (continuous positive airway pressure - CPAP, or oral appliance) and medications (sleep facilitators, e.g., zolpidem; or antidepressants, e.g., trazodone, duloxetine, or neuroleptics, e.g., pregabalin). In the presence of opioid-exacerbated SDB, if the dose cannot be reduced and normal breathing restored, servo-ventilation is a promising avenue that nevertheless requires close medical supervision.

Genome-wide analysis of insomnia disorder

Insomnia is a worldwide problem with substantial deleterious health effects. Twin studies have shown a heritable basis for various sleep-related traits, including insomnia, but robust genetic risk variants have just recently begun to be identified. We conducted genome-wide association studies (GWAS) of soldiers in the Army Study To Assess Risk and Resilience in Servicemembers (STARRS). GWAS were carried out separately for each ancestral group (EUR, AFR, LAT) using logistic regression for each of the STARRS component studies (including 3,237 cases and 14,414 controls), and then meta-analysis was conducted across studies and ancestral groups. Heritability (SNP-based) for lifetime insomnia disorder was significant (h²_g = 0.115, p = 1.78 × 10^-4 in EUR). A meta-analysis including three ancestral groups and three study cohorts revealed a genome-wide significant locus on Chr 7 (q11.22) (top SNP rs186736700, OR = 0.607, p = 4.88 × 10^-9) and a genome-wide significant gene-based association (p = 7.61 × 10^-7) in EUR for RFX3 on Chr 9. Polygenic risk for sleeplessness/insomnia severity in UK Biobank was significantly positively associated with likelihood of insomnia disorder in STARRS. Genetic contributions to insomnia disorder in STARRS were significantly positively correlated with major depressive disorder (r_g = 0.44, se = 0.22, p = 0.047) and type 2 diabetes (r_g = 0.43, se = 0.20, p = 0.037), and negatively with morningness chronotype (r_g = -0.34, se = 0.17, p = 0.039) and subjective well being (r_g = -0.59, se = 0.23, p = 0.009) in external datasets. Insomnia associated loci may contribute to the genetic risk underlying a range of health conditions including psychiatric disorders and metabolic disease.

Genetic Pathways to Insomnia

This review summarizes current research on the genetics of insomnia, as genetic contributions are thought to be important for insomnia etiology. We begin by providing an overview of genetic methods (both quantitative and measured gene), followed by a discussion of the insomnia genetics literature with regard to each of the following common methodologies: twin and family studies, candidate gene studies, and genome-wide association studies (GWAS). Next, we summarize the most recent gene identification efforts (primarily GWAS results) and propose several potential mechanisms through which identified genes may contribute to the disorder. Finally, we discuss new genetic approaches and how these may prove useful for insomnia, proposing an agenda for future insomnia genetics research.