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.

Insomnia.

Insomnia is highly prevalent in clinical practice, occurring in up to 50% of primary care patients. Insomnia can present independently or alongside other medical conditions or mental health disorders and is a risk factor for the development and exacerbation of these other disorders if not treated. In 2016, the American College of Physicians recommended that insomnia be specifically targeted for treatment. The recommended first-line treatment for insomnia, whether the underlying cause has been identified or not, is cognitive behavioural therapy for insomnia (CBT-I). Currently, there is no global consensus regarding which pharmacological treatment has the best efficacy or risk-benefit ratio. Both CBT-I and pharmacological intervention are thought to have similar acute effects, but only CBT-I has shown durable long-term effects after treatment discontinuation. Administering a combined treatment of CBT-I and medication could decrease the latency to treatment response, but might diminish the durability of the positive treatment effects of CBT-I.

Animal models of human insomnia.

Insomnia disorder (chronic sleep continuity disturbance) is a debilitating condition affecting 5%-10% of the adult population worldwide. To date, researchers have attempted to model insomnia in animals through breeding strategies that create pathologically short-sleeping individuals or with drugs and environmental contexts that directly impose sleeplessness. While these approaches have been invaluable for identifying insomnia susceptibility genes and mapping the neural networks that underpin sleep-wake regulation, they fail to capture concurrently several of the core clinical diagnostic features of insomnia disorder in humans, where sleep continuity disturbance is self-perpetuating, occurs despite adequate sleep opportunity, and is often not accompanied by significant changes in sleep duration or architecture. In the present review, we discuss these issues and then outline ways animal models can be used to develop approaches that are more ecologically valid in their recapitulation of chronic insomnia's natural aetiology and pathophysiology. Conditioning of self-generated sleep loss with these methods promises to create a better understanding of the neuroadaptations that maintain insomnia, including potentially within the infralimbic cortex, a substrate at the crossroads of threat habituation and sleep.

On the relationship between EEG spectral analysis and pre-sleep cognitive arousal in insomnia disorder: towards an integrated model of cognitive and cortical arousal.

According to the hyperarousal model, insomnia is characterised by increased arousal in the cortical, cognitive, and physiological domains. However, the interaction between these arousal domains is poorly understood. The present observational case-control study aimed to investigate cortical arousal during the night, pre-sleep cognitive arousal and the relationship between these two domains. A total of 109 patients with insomnia disorder (ID) and 109 age-and gender matched healthy controls were investigated on two sleep laboratory nights. Electroencephalographic (EEG) spectral power during non-rapid eye movement (NREM) and REM sleep was analysed as a measure of cortical arousal. In addition, patients completed the Pre-Sleep Arousal Scale (PSAS), which consists of two subscales, one for cognitive arousal (PSAS-CA) and one for self-reported somatic arousal (PSAS-SA). The relationship between the subscale scores and EEG spectral power was calculated by multi- and univariate analyses of variance. During NREM and REM sleep, patients with ID showed significantly increased spectral power in the EEG gamma band. In addition, patients with ID showed significantly increased scores on both subscales of the PSAS. The PSAS-CA score was significantly associated with increased NREM and REM gamma power, whereas PSAS-SA was associated with decreases in NREM and REM gamma power. Consistent with our hypothesis, patients with ID showed increased cortical and cognitive arousal. Moreover, there was an association between these two arousal domains, which may indicate that cortical arousal during the night is (at least in part) elicited by pre-sleep worry and rumination.

Do Placebos Primarily Affect Subjective as Opposed to Objective Measures? A Meta-Analysis of Placebo Responses in Insomnia RCTs.

INTRODUCTION: Little is known about the relative magnitude of placebo responses on objective and subjective measures of sleep continuity. To address this issue, the pre-post effects of placebos on objective and subjective measures (i.e., polysomnography [PSG] and sleep diaries) were evaluated meta-analytically. The guiding hypothesis was that large responses would be observed on sleep diary measures and small responses would be observed on PSG measures. METHODS: PubMed searches, 1967-2016, yielded 329 possible articles, 17 of which met the inclusion and exclusion criteria for the present analysis (including 879 subjects with PSG data, 1,209 subjects with diary data, and six studies with both PSG and sleep diary data). Average change and weighted effect sizes (ESs) were computed via modeling for sleep latency (SL), wake after sleep onset (WASO) and total sleep time (TST). RESULTS: Pre-to-post change on PSG measures were: SL -13.7 min., ES = -0.37; WASO -14.3 min., ES = -0.36; and TST 29.8 min., ES = 0.50. Pre-to-post change on sleep diary measures were: SL -13.5 min., ES = -0.36; WASO -13.3 min., ES = -0.20; and TST 25.5 min., ES = 0.36. The modeled average objective subjective difference per sleep continuity measure was less than 5 minutes. The modeled average objective subjective difference per sleep continuity measure (in effect sizes) was less than 0.17. DISCUSSION: The observed outcomes of this analysis suggest that placebos produce comparable effects on objective and subjective measures of sleep continuity. Thus, objective measures do not appear to protect against placebo responses. This being the case and given the importance of the subjective experience of illness severity and recovery, such data suggests that prospectively sampled sleep continuity data (sleep diaries) may be the optimal data for clinical trials, particularly when only one measure is possible.

A Drosophila model of sleep restriction therapy for insomnia.

Insomnia is the most common sleep disorder among adults, especially affecting individuals of advanced age or with neurodegenerative disease. Insomnia is also a common comorbidity across psychiatric disorders. Cognitive behavioral therapy for insomnia (CBT-I) is the first-line treatment for insomnia; a key component of this intervention is restriction of sleep opportunity, which optimizes matching of sleep ability and opportunity, leading to enhanced sleep drive. Despite the well-documented efficacy of CBT-I, little is known regarding how CBT-I works at a cellular and molecular level to improve sleep, due in large part to an absence of experimentally-tractable animals models of this intervention. Here, guided by human behavioral sleep therapies, we developed a Drosophila model for sleep restriction therapy (SRT) of insomnia. We demonstrate that restriction of sleep opportunity through manipulation of environmental cues improves sleep efficiency in multiple short-sleeping Drosophila mutants. The response to sleep opportunity restriction requires ongoing environmental inputs, but is independent of the molecular circadian clock. We apply this sleep opportunity restriction paradigm to aging and Alzheimer's disease fly models, and find that sleep impairments in these models are reversible with sleep restriction, with associated improvement in reproductive fitness and extended lifespan. This work establishes a model to investigate the neurobiological basis of CBT-I, and provides a platform that can be exploited toward novel treatment targets for insomnia.

Insomnia Severity and Degree of Dysfunction: What Is to Be Learned When These Domains are Discordant?

OBJECTIVE/BACKGROUND: Illness severity and resultant dysfunction are often linearly related and tightly coupled (concordant). Some percentage of individuals, however, exhibit discordant associations (high illness severity and low dysfunction [HL] or low illness severity and high dysfunction [LH]). In the present study, a sample of subjects with insomnia complaints were evaluated to determine what percentage of subjects exhibited discordant associations. PARTICIPANTS: Archival data were drawn from a community-based sample (n = 4,680; 61.8% female; Ages 18-105). METHODS: Median splits were calculated for illness severity and daytime dysfunction and each individual was typed as High (H) or Low (L) for the concordant (HH and LL) and discordant domains (HL and LH). RESULTS: Given this typology, 61% were classified as concordant and 39% were classified as discordant. Of these, 38% were sub-typed as HH, 23% as LL, 26% as LH, and 13% as HL. CONCLUSIONS: We propose that some of the discordance may be ascribable to a mismatch between sleep need and sleep ability. Those "who need a lot, may suffer a lot, in the face of only a little (LH)", whereas those "who need a little, may suffer only a little, in the face of a lot (HL)".

The natural history of insomnia: Does sleep extension differentiate between those that do and do not develop chronic insomnia?

According to the "3P model" of insomnia, the variable that mediates the transition from acute insomnia (AI) to chronic insomnia is "sleep extension" (the behavioural tendency to expand sleep opportunity to compensate for sleep loss). In the present analysis, we sought to evaluate how time in bed (TIB) varies relative to the new onset of AI and chronic insomnia. A total of 1,248 subjects were recruited as good sleepers (GS). Subjects were monitored over 1 year with sleep diaries. State transitions were defined, a priori, for AI, recovered from AI (AI-REC), and for chronic insomnia (AI-CI). Two additional groupings were added based on profiles that were unanticipated: subjects that exhibited persistent poor sleep following AI (AI-PPS [those that neither recovered or developed chronic insomnia]) and subjects that recovered from chronic insomnia (CI-REC). All the groups (GS, AI-REC, AI-CI, AI-PPS and CI-REC) were evaluated for TIB differences with longitudinal mixed effects models. Post hoc analyses for the percentage of the groups that were typed as TIB "restrictors, maintainers, and expanders" were conducted using longitudinal mixed effects models and contingency analyses. Significant differences for pre-post AI TIB were not detected for the insomnia groups. Trends were apparent for the AI-CI group, which suggested that minor increases in TIB occurred weeks before the declared onset of AI. Additionally, it was found that a significantly larger percentage of AI-CI subjects engaged in sleep extension (as compared to GS). The present data suggest that transition from AI to chronic insomnia does not appear to be initiated by sleep extension and the transition may occur before the elapse of 3 months of ≥3 nights of sleep continuity disturbance. Given these findings, it may be that the mismatch between sleep ability and sleep opportunity is perpetuated over time given the failure to "naturally" engage in sleep restriction (as opposed to sleep extension).

The European Academy for Cognitive Behavioural Therapy for Insomnia: An initiative of the European Insomnia Network to promote implementation and dissemination of treatment.

Insomnia, the most prevalent sleep disorder worldwide, confers marked risks for both physical and mental health. Furthermore, insomnia is associated with considerable direct and indirect healthcare costs. Recent guidelines in the US and Europe unequivocally conclude that cognitive behavioural therapy for insomnia (CBT-I) should be the first-line treatment for the disorder. Current treatment approaches are in stark contrast to these clear recommendations, not least across Europe, where, if any treatment at all is delivered, hypnotic medication still is the dominant therapeutic modality. To address this situation, a Task Force of the European Sleep Research Society and the European Insomnia Network met in May 2018. The Task Force proposed establishing a European CBT-I Academy that would enable a Europe-wide system of standardized CBT-I training and training centre accreditation. This article summarizes the deliberations of the Task Force concerning definition and ingredients of CBT-I, preconditions for health professionals to teach CBT-I, the way in which CBT-I should be taught, who should be taught CBT-I and to whom CBT-I should be administered. Furthermore, diverse aspects of CBT-I care and delivery were discussed and incorporated into a stepped-care model for insomnia.

Insomnia Symptoms and Suicide-Related Ideation in U.S. Army Service Members.

Background: Insomnia has been identified as a key risk factor for suicide, though most studies have been limited to global measures of these constructs. The aim of the present study was to evaluate the link between insomnia symptoms and five different aspects of suicide-related ideation. Participants: 1,160 active U.S. Army service members (719 male; Mage = 31.2; SDage = 8.62). Methods: As part of an archival analysis, retrospectively assessed insomnia, depression, anxiety symptoms, as well as suicide-related ideation, were evaluated. Suicide-related ideation was assessed in terms of: thoughts of death, thoughts of suicide, suicidal plan, suicidal intent, and suicidal communication. Results: Subjects with clinically significant insomnia symptoms were 3.5 times more likely to report any suicide-related ideation, and approximately 3 times more likely to report thoughts of death and thoughts of suicide. More frequent nocturnal awakenings (i.e., waking up three or more times during a single night) were associated with a greater likelihood of reporting thoughts of death or suicide, whereas greater middle insomnia (i.e., waking up and having difficulty getting back to sleep) was associated with lower odds of experiencing thoughts of suicide, suicidal plan, and suicidal intent. Conclusions: A more refined delineation of insomnia and suicide-related ideation may serve to clarify the nature of the association, and potentially offer some clues as to the underlying mechanisms. With regard to potential clinical implications, the results support that careful assessment of insomnia symptoms, suicide-related ideation, and their respective subtypes, is important and may influence how we estimate risk for suicide.

Cognitive Behavioral Therapy for Insomnia in Alcohol-Dependent Veterans: A Randomized, Controlled Pilot Study.

BACKGROUND: Insomnia is highly prevalent in individuals recovering from alcohol dependence (AD) and increases their risk of relapse. Two studies evaluating cognitive behavior therapy for insomnia (CBT-I) have demonstrated its efficacy in non-Veterans recovering from AD. The aim of this study was to extend these findings in an 8-week trial of CBT-I in Veterans. METHODS: Veterans recovering from AD were randomly assigned to 8 weeks of treatment with CBT-I (N = 11) or a Monitor-Only (MO; N = 11) condition and were evaluated 3 (N = 21/22) and 6 months posttreatment (N = 18/22). The primary outcome measure was the Insomnia Severity Index (ISI) score. Secondary outcome measures were sleep diary measures, percent days abstinent (PDA), and scores on the Dysfunctional Beliefs and Attitudes About Sleep Scale (DBAS), Sleep Hygiene Index (SHI), Penn Alcohol Craving Scale (PACS), Quick Inventory of Depressive Symptoms (QIDS), State-Trait Anxiety Inventory-Trait (STAI-T) scale, and Short Form 12-item (SF-12). Mixed-effects regression models, adjusted for race, evaluated differences in outcomes between the groups over a 6-month period (clinicaltrials.gov identifier = NCT01603381). RESULTS: Subjects were male, aged 54.5 (SD = 6.9) years, and had 26.4 (SD = 26.3) days of abstinence before their baseline evaluation. CBT-I produced a significantly greater improvement in model-based estimates than MO (mean change at 6 months compared to their baseline) for ISI, sleep latency from a daily sleep diary, DBAS mean score, and SHI total score. PDA and QIDS improved over time, but there was no difference between the groups. PACS, STAI-T, or SF-12 scale did not show any improvement from their baseline scores. CONCLUSIONS: CBT-I treatment demonstrated substantial efficacy in reducing insomnia, associated negative cognitions, and improving sleep hygiene in Veterans during early recovery, though it did not reduce drinking behavior.

Social Support, Insomnia, and Adherence to Cognitive Behavioral Therapy for Insomnia After Cancer Treatment.

OBJECTIVE/BACKGROUND: While cognitive-behavioral therapy for insomnia (CBT-I) has been shown to be efficacious in treating cancer survivors' insomnia, 30-60% of individuals have difficulty adhering to intervention components. Psychosocial predictors of adherence and response to CBT-I, such as social support, have not been examined in intervention studies for cancer survivors. PARTICIPANTS: Data from a randomized placebo-controlled 2 x 2 trial of CBT-I and armodafinil (a wakefulness promoting agent) were used to assess adherence. Ninety-six cancer survivors participated in the trial (mean age 56, 86% female, 68% breast cancer). METHODS: CBT-I and armodafinil were administered over the course of seven weeks, and participants were assessed at baseline, during intervention, postintervention, and at a three-month follow-up. Social support was assessed using a Functional Assessment of Chronic Illness Therapy subscale, insomnia severity was assessed using the Insomnia Severity Index, and adherence was measured based on CBT-I sleep prescriptions. RESULTS: At baseline, social support was negatively correlated with insomnia severity (r = -0.30, p = 0.002) and associations between social support, CBT-I, and insomnia were maintained through the three-month follow-up. Social support was positively associated with adherence to CBT-I during intervention weeks 3, 4, and 5, and with overall intervention adherence. At postintervention, both social support and treatment with CBT-I independently predicted decreased insomnia severity (p < 0.01) when controlling for baseline insomnia severity. CONCLUSIONS: Higher social support is associated with better intervention adherence and improved sleep independent of CBT-I. Additional research is needed to determine whether social support can be leveraged to improve adherence and response to CBT-I.

Cognitive behavioral therapy for insomnia, but not armodafinil, improves fatigue in cancer survivors with insomnia: a randomized placebo-controlled trial.

PURPOSE: Fatigue is a prevalent, distressing side effect of cancer and cancer treatment which commonly coexists with insomnia. Cognitive behavioral therapy for insomnia (CBT-I) has been shown to improve insomnia in cancer patients, but less is known about its ability to impact fatigue. This work is the analysis for a secondary aim of a four-arm randomized controlled trial (RCT) study assessing the combined and comparative effect of CBT-I and a wakefulness-promoting agent, armodafinil (A), to improve sleep and daytime functioning in cancer survivors. Herein, we examine the effect of CBT-I, with and without A, on fatigue in cancer survivors. PATIENTS AND METHODS: This study was a four-arm factorial study with CBTI-I (yes/no) versus A (yes/no). It consisted of 96 cancer survivors (average age 56 years; 88 % female; 68 % breast cancer). Fatigue was assessed by the brief fatigue inventory (BFI) and the FACIT-Fatigue scale. The analysis assessed the additive effects of CBT-I and A and possible non-additive effects where the effect of CBT-I changes depending on the presence or absence of A. RESULTS: Analyses adjusting for baseline differences showed that CBT-I improved fatigue as measured by two separate scales (BFI: P = 0.002, Std. error = 0.32, effect size (ES) = 0.46; FACIT-Fatigue: P < 0.001, Std. error = 1.74, ES = 0.64). Armodafinil alone did not show a statistically significant effect on fatigue levels (all Ps > 0.40) nor did the drug influence the efficacy of CBT-I. Structural equation analysis revealed that reductions in insomnia severity were directly responsible for improving cancer-related fatigue. CONCLUSIONS: CBT-I with and without armodafinil resulted in a clinically and statistically significant reduction of subjective daytime fatigue in cancer survivors with chronic insomnia. Armodafinil did not improve cancer-related fatigue (CRF) and did not change the efficacy of CBT-I. Patients reporting CRF should be screened and, if indicated, treated for insomnia as part of a comprehensive fatigue management program.

Where are the Behavioral Sleep Medicine Providers and Where are They Needed? A Geographic Assessment.

Although it is widely acknowledged that there are not enough clinicians trained in either Behavioral Sleep Medicine (BSM) in general or in Cognitive Behavioral Therapy for Insomnia (CBT-I) in specific, what is unclear is whether this problem is more acute in some regions relative to others. Accordingly, a geographic approach was taken to assess this issue. Using national directories as well as e-mail listservs (Behavioral Sleep Medicine group and Behavioral Treatment for Insomnia Roster), the present study evaluated geographic patterning of CBSM and BSM providers by city, state, and country. Overall, 88% of 752 BSM providers worldwide live in the United States (n = 659). Of these, 58% reside in 12 states with ≥ 20 providers (CA, NY, PA, IL, MA, TX, FL, OH, MI, MN, WA, and CO), and 19% reside in just 2 states (NY and CA). There were 4 states with no BSM providers (NH, HI, SD, and WY). Of the 167 U.S. cities with a population of > 150,000, 105 cities have no BSM providers. These results clearly suggest that a targeted effort is needed to train individuals in both the unserved and underserved areas.

Sleep disturbances as an evidence-based suicide risk factor.

Increasing research indicates that sleep disturbances may confer increased risk for suicidal behaviors, including suicidal ideation, suicide attempts, and death by suicide. Despite increased investigation, a number of methodological problems present important limitations to the validity and generalizability of findings in this area, which warrant additional focus. To evaluate and delineate sleep disturbances as an evidence-based suicide risk factor, a systematic review of the extant literature was conducted with methodological considerations as a central focus. The following methodologic criteria were required for inclusion: the report (1) evaluated an index of sleep disturbance; (2) examined an outcome measure for suicidal behavior; (3) adjusted for presence of a depression diagnosis or depression severity, as a covariate; and (4) represented an original investigation as opposed to a chart review. Reports meeting inclusion criteria were further classified and reviewed according to: study design and timeframe; sample type and size; sleep disturbance, suicide risk, and depression covariate assessment measure(s); and presence of positive versus negative findings. Based on keyword search, the following search engines were used: PubMed and PsycINFO. Search criteria generated N = 82 articles representing original investigations focused on sleep disturbances and suicide outcomes. Of these, N = 18 met inclusion criteria for review based on systematic analysis. Of the reports identified, N = 18 evaluated insomnia or poor sleep quality symptoms, whereas N = 8 assessed nightmares in association with suicide risk. Despite considerable differences in study designs, samples, and assessment techniques, the comparison of such reports indicates preliminary, converging evidence for sleep disturbances as an empirical risk factor for suicidal behaviors, while highlighting important, future directions for increased investigation.

Cost-effectiveness of cognitive behavioral therapy for insomnia comorbid with depression: Analysis of a randomized controlled trial.

AIM: Although the efficacy of cognitive behavioral therapy for insomnia has been confirmed, dissemination depends on the balance of benefits and costs. This study aimed to examine the cost-effectiveness of cognitive behavioral therapy for insomnia consisting of four weekly individual sessions. METHODS: We conducted a 4-week randomized controlled trial with a 4-week follow up in outpatient clinics in Japan. Thirty-seven patients diagnosed as having major depressive disorder according to DSM-IV and suffering from chronic insomnia were randomized to receive either treatment as usual (TAU) alone or TAU plus cognitive behavioral therapy for insomnia. Effectiveness was evaluated as quality-adjusted life years (QALY) over 8 weeks' time, estimated by bootstrapping of the observed total scores of the Hamilton Depression Rating Scale. Direct medical costs for cognitive behavioral therapy for insomnia and TAU were also evaluated. We calculated the incremental cost-effectiveness ratio. RESULTS: Over the 8 weeks of the study, the group receiving cognitive behavioral therapy for insomnia plus TAU had significantly higher QALY (P = 0.002) than the TAU-alone group with an incremental value of 0.019 (SD 0.006), and had non-significantly higher costs with an incremental value of 254 (SD 203) USD in direct costs. The incremental cost-effectiveness ratio was 13 678 USD (95% confidence interval: -5691 to 71 316). Adding cognitive behavioral therapy for insomnia demonstrated an approximately 95% chance of gaining one more QALY if a decision-maker was willing to pay 60 000 USD, and approximately 90% for 40 000 USD. CONCLUSION: Adding cognitive behavioral therapy for insomnia is highly likely to be cost-effective for patients with residual insomnia and concomitant depression.

The effects of quetiapine on sleep in recovering alcohol-dependent subjects: a pilot study.

OBJECTIVE: The aim of this hypothesis-generating pilot study was to assess prospectively the objective and subjective effects of treatment with quetiapine XR on sleep during early recovery from alcohol dependence (AD). METHODS: Recovering subjects with AD and sleep disturbance complaints were treated with quetiapine XR (n = 10) or matching placebo pills (n = 10) for 8 weeks. Polysomnography was used to assess sleep objectively, and the Insomnia Severity Index and Pittsburgh Sleep Quality Index were used to measure subjective insomnia. Other assessment measures included the 10-minute psychomotor vigilance task (for neurobehavioral functioning), the time-line follow-back measure (for alcohol consumption), the Penn Alcohol Craving Scale (for alcohol craving), the Patient Health Questionnaire-9 item scale (for depressive symptoms), and the Beck Anxiety Inventory (for anxiety symptoms). RESULTS: Although there was no effect of quetiapine XR on sleep efficiency (time spent asleep/total recording time), there was a pre-to-post reduction in wake after sleep onset time (P = 0.03) and nonsignificant trends for increases in sleep onset latency (SOL) and stage 2 sleep time. A time × drug interaction was seen for the subjective insomnia, such that quetiapine XR-treated subjects reported greater initial improvement in their subjective insomnia, but the difference was not sustained. There were no differences between treatment groups on other measures or medication compliance. CONCLUSION: Quetiapine XR improves objective sleep continuity and transiently improves subjective insomnia early in recovery from AD.

The incidence and temporal patterning of insomnia: a second study.

Whether subjects with insomnia exhibit good sleep on some interval basis is unclear. Prior research suggests that patients with insomnia are highly variable with respect to night-to-night sleep continuity, that more than 40% of patients exhibit temporal patterning of good sleep, and that nearly 90% of patients exhibit better than average sleep following 1 to 3 nights of relatively poor sleep. The aim of the present study was to replicate and extend the above-noted findings utilizing: (i) a large sample studied over an extended time interval (ii) absolute standards for 'good' and 'poor' sleep; and (iii) a formal statistical methodology to assess temporal patterning and the association of time in bed with bout duration of poor or average sleep. Thirty-three subjects with insomnia and 33 good sleepers completed sleep diaries over the course of 110 days. It was found that subjects with insomnia (compared to good sleepers) had more poor nights (e.g. about 39 versus 7% of the assessed nights), a higher probability of a having a poor night on any given occasion (60% greater probability than good sleepers) and more consecutive nights of poor sleep between good sleep nights (median bout duration of approximately three versus one night). Lastly, it was found that (as would be predicted by both the Spielman model and the two-process model) time in bed moderated bout duration in the insomnia group. That is, longer times in bed were associated with longer bouts of poor sleep.

Move your feet and sleep: A longitudinal dynamic analysis of self-reported exercise, sedentary behavior, and insomnia symptoms.

INTRODUCTION: Insomnia symptoms are associated with poor physical and mental health. Exercise is associated with good sleep while sedentary behavior is associated with poor sleep. This study investigated the longitudinal, dynamic associations among exercise, sedentary behavior, and insomnia symptoms. METHODS: Seven hundred and fifty-six adults (Mage=47.2years, 54.9% female) took part in an online longitudinal study investigating sleep and health across the lifespan. Participants reported duration of moderate-to-strenuous exercise, percentage of day spent sitting, and insomnia symptoms (Insomnia Severity Index [ISI]). The ISI was scored as a total score and two-factor scores: (1) Sleep Disturbance (items 1, 2, 3) and (2) Daytime Dysfunction (items 4, 5, 6, 7). Multilevel modeling was used to examine the typical (i.e., between-persons) and individual (i.e., within-persons) associations among sedentary behavior, exercise, and insomnia symptoms. RESULTS: Sedentary behavior was significantly associated with total ISI scores at both the between-person and within-person levels (ß = 0.036, t = 3.23, p = .001; ß = 0.014, t = 1.99, p = .048). Both between-persons and within-person levels of sedentary behavior were associated with Daytime Dysfunction (ß = 0.028, t = 3.79, p < .001; ß = 0.009, t = 2.08, p = .039). Exercise was associated with total ISI and Daytime Dysfunction scores at the between-persons level but not at the within-persons level (ß = 0.028, t = 2.57, p = .01; ß = -0.002, t = -3.02, p = .003). CONCLUSIONS: Sedentary behavior was a more consistent and robust predictor of insomnia symptoms than exercise. The association between sedentary behavior and insomnia symptoms was dynamic in that when an individual reported being more sedentary than their norm, they also reported more insomnia symptoms. Future analyses should examine potential moderator variables and comorbid conditions.

Empirical clustering to identify individuals for whom insomnia is more closely related to suicidal ideation.

BACKGROUND: Although the effect sizes are modest, insomnia is consistently associated with suicidal thoughts and behaviors. Subgroup analyses can efficiently identify for whom insomnia is most relevant to suicidal ideation. To improve clinical case identification, the present study sought to identify subclusters of lifetime suicidal ideators for whom insomnia was most closely related to current suicidal ideation. METHODS: Data on N = 4750 lifetime suicidal ideators were extracted from the Military Suicide Research Consortium's Common Data Elements. Data on sociodemographic characteristics, severity and history of suicidal thoughts and behaviors, and related clinical characteristics were clustered by unsupervised machine learning algorithms. Robust Poisson regression estimated cluster by insomnia associations with current suicidal ideation. RESULTS: Three clusters were identified: a modest symptom severity cluster (N = 1757, 37.0 %), an elevated severity cluster (N = 1444 30.4 %), and a high severity cluster (N = 1549 32.6 %). In Cluster 1, insomnia was associated with current suicidal ideation (PRR 1.29 [1.13-1.46]) and remained significant after adjusting for sociodemographic and clinical covariates. In Cluster 2, insomnia was associated with current suicidal ideation (PRR 1.14 [1.01-1.30]), but not after adjusting for sociodemographic and clinical covariates. In Cluster 3, insomnia was associated with current suicidal ideation (PRR 1.12 [1.03-1.21]) and remained significant after adjusting for sociodemographic covariates, but not clinical covariates. LIMITATIONS: Cross-sectional design, lack of diagnostic data, non-representative sample. CONCLUSION: Insomnia appears more closely related to current suicidal ideation among modest severity individuals than other subgroups. Future work should use prospective designs and more comprehensive risk factor measures to confirm these findings.