The attention-intention-effort pathway in the development of psychophysiologic insomnia: a theoretical review

A Neurobiological Model of Insomnia

Insomnia is a common clinical condition resulting in significant costs and morbidity. Previous models of insomnia focusing on psychological and behavioral processes are useful clinically, but lack neurobiological specificity. We propose an insomnia model based on basic and clinical neuroscience findings, and hypothesize that insomnia results from persistent activity in wake-promoting neural structures during NREM sleep. The simultaneous occurrence of sleeping and waking neural activity helps to explain clinical phenomenology and treatment effects in insomnia.

Time will tell: a retrospective study investigating the relationship between insomnia and objectively defined punctuality

Primary insomnia is a prevalent sleep disorder affecting approximately 3% of the general population. Studies suggest that personality traits such as perfectionism and neuroticism might be implicated in the aetiology of the disorder. However, to date, no study has investigated behavioural indicators of these factors in a hypothesis-driven manner. In the present study, we assessed punctuality as a behavioural indicator of perfectionism and neuroticism in 635 consecutive clinical patients of the sleep laboratory of the Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center. The primary aim was to compare primary insomnia patients (n = 148) with another group of patients with other sleep-related diagnoses (n = 487). Primary insomnia patients arrived on average 4 min earlier when compared to other patients (P = 0.041). However, this effect failed to reach statistical significance when correcting for the influence of potential confounding variables. Of note, we found a strong relationship between polysomnographic sleep parameters and punctuality. That is, short sleep duration was associated significantly with early arrival times at the sleep laboratory (P = 0.023). These findings support the proposal that personality traits, which we predict underlie obsessive punctuality, may be involved in the aetiology of objectively defined sleep disturbances. Clinical implications of the current results for cognitive behavioural treatments of insomnia are discussed.

The influence of pre-sleep cognitive arousal on sleep onset processes

Cognitive hyperarousal, resulting in enhanced cognitive activation, has been cited as an important contributor to the development and preservation of insomnia. To further understand this process, our study examined the effects of acutely-induced pre-sleep cognitive hyperarousal on sleep onset processes in healthy volunteers. Following an adaptation night, 15 subjects slept two nights in our sleep laboratory: one reference night and another one with cognitive arousal induction, in a counterbalanced order. In the cognitive arousal condition, subjects worked through half an hour of cognitive tasks without interference of an emotional component prior to retiring to bed. Objective sleep onset latency was significantly prolonged in the cognitive arousal condition compared to the reference condition. Significantly more high frequency activity was recorded during the first and second deep-sleep period. Moreover, differences in heart rate and proximal temperature during and after sleep onset were observed in the nights after the cognitive induction. Pre-sleep cognitive activation successfully induced a significant cognitive load and activation in our subjects to influence subsequent sleep (onset) processes.

No pain, no gain: an exploratory within-subjects mixed-methods evaluation of the patient experience of sleep restriction therapy (SRT) for insomnia

OBJECTIVE

To explore the patient experience of Sleep Restriction Therapy (SRT) for insomnia, with particular focus on elucidating possible side-effects, challenges to adherence and implementation and perceptions of benefit/impact.

METHODS

To fully investigate the patient experience of sleep restriction therapy for insomnia we designed a within-subjects mixed-method study, employing sleep and daytime functioning questionnaires, assessments of sleep-restriction-related side-effects, prospective qualitative audio-diaries and post-treatment semi-structured interviews. University of Glasgow Sleep Centre. Eighteen patients with Primary Insomnia (mean age=42; range 18-64). Patients took part in a 4-week brief sleep restriction intervention, involving two group sessions and two subsequent follow-up phone calls in the home environment.

MEASUREMENTS AND RESULTS

Sleep diaries and global measures of insomnia severity and sleep quality, as expected, demonstrated robust improvements at both post-treatment and 3-month follow-up (all large effect sizes). Daytime functioning/health-related quality of life variables similarly evidenced strong treatment effects (moderate to large effect sizes). Reported side-effects were common, with ≥50% of patients reporting impairment in 8 out of 12 listed symptoms as a consequence of initiating treatment. The four most common side-effects were 'fatigue/exhaustion' (100%), 'extreme sleepiness' (94%), 'reduced motivation/energy' (89%) and 'headache/migraine' (72%) [Mean number of symptoms per patient=7.2 (2.4); range 3-11]. Intriguingly, both side-effect frequency and ratings of side-effect interference were associated with baseline to post-treatment improvements in sleep quality. Qualitative real-time audio-diaries during week 1 of treatment and post-treatment interviews provided rich accounts of side-effects associated with acute SRT implementation; general challenges surrounding treatment implementation and adherence/non-adherence; and modifications to sleep parameters, daytime functioning and perceptions of sleep/sleep period.

CONCLUSIONS

This work has important implications for the delivery of SRT, particularly concerning awareness of possible 'adverse events' and likely implementation/adherence challenges. Findings also pave the way for testable hypotheses concerning possible mechanisms of action involved in sleep restriction treatment.

The association of dysfunctional beliefs about sleep with vulnerability to stress-related sleep disturbance in young adults

This study aims to explore the association between dysfunctional sleep beliefs and vulnerability to stress-related transient sleep disturbance in people without sleep disturbance. One hundred thirty-two good sleepers and 307 poor sleepers were included in this study. As expected, poor sleepers showed more dysfunctional beliefs than good sleepers on the Dysfunctional Beliefs and Attitudes about Sleep scale-10 item version (DBAS-10). More important, even in good sleepers, DBAS-10 scores positively correlated with the vulnerability to stress-related sleep disturbance as measured by the Ford Insomnia Response to Stress Test. The results suggest that dysfunctional sleep belief is not only a perpetuating factor for chronic insomnia, it may also serve as a risk factor for stress-related transient insomnia.

Event-related potentials during the transition to sleep for individuals with sleep-onset insomnia

Event-related potentials may be applied to directly measure information-processing deficits associated with the problem of insomnia. This study is a systematic investigation of cortical hyperarousal during the sleep-onset period in participants with sleep-onset insomnia complaints. Thirteen poor sleepers and twelve good sleepers (GS) were administered an oddball task while awake in the morning and evening and during repeated sleep-onset attempts. Participants signaled detection of a higher pitch target tone as they fell asleep. P2 amplitude was significantly smaller for poor sleepers compared to GS, following standard stimuli at all fronto-central sites, in the pre-sleep waking period at sleep onset. Groups did not differ for N1, N350, or P300 in wake, Stage 1, or Stage 2. The smaller P2 indicates that poor sleepers failed to inhibit the irrelevant standard stimuli. This hyper-attentiveness may explain chronic problems with sleep initiation and could be the target of behavioral and pharmaceutical treatment strategies.

The options available in cognitive behavioral therapy to prevent chronification of insomnia

Insomnia is a very frequent problem among the general population, and it has a high socio-economic impact on health care management. It produces high costs because of absenteeism and accidents, and it is considered to be a risk factor for the development of psychiatric diseases and other medical disorders. However, only a low proportion of insomniacs ever seek professional help. The reasons are still unknown, but most insomniacs probably consider their problem untreatable unless they undergo a therapy with hypnotics. Knowledge about alternative therapy methods beyond sleep medication is scarce, and specialized psychotherapy is not always available. Since dysfunctional behavior and beliefs are considered to be the central perpetuating factors for primary insomnia, the role of educational programs in terms of prevention and treating mild forms of insomnia is discussed. These workshops could be a part of a step-by-step treatment of insomnia as has been proposed recently by Espie.

Heart rate and heart rate variability in subjectively reported insomnia

According to epidemiological studies, insomnia is associated with cardiovascular mortality. However, it is yet to be determined whether this link is mediated by known cardiovascular risk factors. The current study aimed at investigating the association between primary insomnia, defined as subjectively reported sleep disturbance in the absence of any other pathology or substance intake, and alterations in polysomnographically determined nocturnal heart rate (HR) and heart rate variability (HRV). A total of 4,581 nocturnal short-term electrocardiographic recordings (5 min each) from 104 participants (58 with primary insomnia, 46 healthy controls) were evaluated for HR as well as for time and frequency domain measures of HRV. In the primary insomnia group, we found a lower wake-to-sleep HR reduction and a lower standard deviation of RR intervals (SDNN) compared to healthy controls. However, between-group differences in resting HR were not found, and previous results of an increase in sympathovagal balance and a decrease in parasympathetic nocturnal activity in objectively determined insomnia could not be confirmed in our sample of self-report insomnia patients. When restricting our analyses to insomnia patients with objectively determined short sleep duration, we found reduced parasympathetic activity as indicated by decreased high frequency power of HRV, as well as decreased root mean square of successive RRI differences (RMSSD) and percentage of successive RRIs that differ by more than 50 ms (pNN50) values. A lower wake-to-sleep HR reduction and alterations in HRV variables might, at least partially, mediate the increased rates of cardiovascular morbidity and mortality observed in insomnia patients.

Acute insomnia: current conceptualizations and future directions

Despite significant contributions made in the area of persistent/chronic insomnia, especially with regard to the underlying mechanisms driving its maintenance, the area of acute insomnia has received comparatively little attention. The aim of this paper is to review the literature with regard to understanding the situational and personaological circumstances that surround the development of acute insomnia. The review begins by examining how the existing diagnostic systems conceptualise acute insomnia. Theoretical models that explain, or inferentially explain, the transition between normal sleep and acute insomnia are then explored and evaluated. The review then examines the current evidence base in terms of the pathogenesis of acute insomnia from naturalistic and experimental studies. Overall, the findings from the review confirm the paucity of evidence available but perhaps more importantly highlight the need for a structured diagnosis of acute insomnia as the first step in a research and treatment strategy. To this end a diagnostic system, drawing on the existing literature on stress and the systems used to diagnose depression, is forwarded and justified and a research agenda advanced.

Psychological and behavioral factors in patients with comorbid obstructive sleep apnea and insomnia

OBJECTIVE

Insomnia symptoms in patients with obstructive sleep apnea (OSA) are commonly assumed to be secondary to respiratory disturbances. Previous studies, however, showed that insomnia might persist after treatment for OSA. Higher levels of emotional disturbances were reported in OSA patients with insomnia than those without insomnia, which suggests that psychological factors may play an important role for their sleep difficulties. This study aimed to further explore sleep-related psychological/behavioral factors that may contribute to insomnia in OSA patients.

METHODS

This study included 88 men, of which 33 had OSA (OSA group); 29, primary insomnia; (Insomnia group); and 26, both OSA and insomnia (OSA+Insomnia group). All subjects underwent polysomnography (PSG) overnight and completed a package of questionnaires, including the Insomnia Severity Index (ISI), Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS), Sleep Hygiene Practice Scale (SHPS), Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI), and Pre-Sleep Arousal Scale (PSAS).

RESULTS

The OSA+Insomnia and Insomnia groups had significantly more dysfunctional sleep beliefs, more arousal-inducing sleep-related behaviors, and higher levels of pre-sleep arousal, anxiety, and depression than did the OSA group. The respiratory indices and arousal index were higher for OSA and OSA+Insomnia groups than for the Insomnia group.

CONCLUSION

Although OSA patients with insomnia showed a similar degree of respiratory disturbances as patients with OSA only, their psychological and behavioral profiles resembled the features of primary insomnia patients. The results support the concept of comorbid insomnia and suggest the importance of evaluating and treating both physiological and psychological factors in these patients.

Moving beyond average values: assessing the night-to-night instability of sleep and arousal in DSM-IV-TR insomnia subtypes

STUDY OBJECTIVES

We explored differences between individuals with DSM-IV-TR diagnoses of primary insomnia (PI) and insomnia related to a mental disorder (IMD) by using serial measurements of self-reported sleep variables (sleep onset latency, SOL; wake after sleep onset, WASO; total sleep time, TST; sleep efficiency, SE), and visual analogue scale ratings of 2 forms of bedtime arousal (cognitive and emotional). Furthermore, we sought to examine the relationship between sleep and arousal within each diagnostic subgroup.

DESIGN

Between-group and within-group comparisons.

SETTING

Duke and Rush University Medical Centers, USA.

PARTICIPANTS

One hundred eighty-seven insomnia sufferers (126 women, average age 47.15 years) diagnosed by sleep specialists at 2 sleep centers as PI patients (n=126) and IMD patients (n=61).

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Multilevel models for sleep measures indicated that IMD displayed significantly more instability across nights in their TST (i.e., larger changes) than did PI patients. With respect to pre-sleep arousal, IMD patients exhibited higher mean levels of emotional arousal, as well as more instability on the nightly ratings of this measure. Within the PI group, correlational analyses revealed a moderate relationship between the 2 arousal variables and SOL (r values 0.29 and 0.26), whereas the corresponding correlations were negligible and statistically nonsignificant in the IMD group.

CONCLUSIONS

We found a number of differences on nighttime variables between those diagnosed with primary insomnia and those diagnosed with insomnia related to a mental disorder. These differences imply different perpetuating mechanisms involved in their ongoing sleep difficulties. Additionally, they support the categorical distinctiveness and the concurrent validity of these insomnia subtypes.

Meta-analytic review of the impact of cognitive-behavior therapy for insomnia on concomitant anxiety

INTRODUCTION

Concomitant anxiety and insomnia is a frequent problem encountered by mental health professionals.

PRIMARY OBJECTIVE

To assess the impact of cognitive-behavior therapy for insomnia (CBT-I) on associated anxiety.

METHOD

Systematic search for clinical trials of CBT-I in PsycInfo, Medline, and Proquest Dissertations and Theses.

RESULTS

Of the 216 CBT-I trials reviewed, 72 (33.3%) reported data on anxiety. The combined effect size (ES) of CBT-I on anxiety was 0.406 [95% CI 0.318-0.493], indicating a small to moderate effect of CBT-I on concomitant anxiety. Anxiety and anxiety-related constructs were measured with 31 different questionnaires or questionnaire subscales, the majority of which were used only once in the sample of studies.

CONCLUSIONS

CBT-I has only a moderate impact on anxiety in individuals who present insomnia with or without a comorbid anxiety disorder. A careful evaluation of residual anxiety should be conducted subsequent to CBT-I. Further research should focus on standardizing the assessment of anxiety in insomnia research.

Psychophysiological reactivity to sleep-related emotional stimuli in primary insomnia

The present study examined psychophysiological reactivity to emotional stimuli related and non-related to sleep in people with primary insomnia (PPI) and in good sleepers (GS). Twenty-one PPI and 18 GS were presented with five blocks of neutral, negative, positive, sleep-related negative and sleep-related positive pictures. During the presentation of the pictures, facial electromyography (EMG) of the corrugator and the zygomatic muscles, heart rate (HR) and cardiac vagal tone (CVT) were recorded. Subjective ratings of the stimuli were also collected. We found that only PPI exhibited greater inhibition of the corrugator activity in response to sleep-related positive stimuli compared to the other blocks of stimuli. Furthermore, PPI rated the sleep-related negative stimuli as more unpleasant and arousing and showed higher CVT in response to all stimuli as compared to GS. Results were interpreted as indicating that PPI exhibit craving for sleep-related positive stimuli, and also hyper-arousability in response to sleep-related negative stimuli, as compared to GS. Our results suggest that psychological treatment of insomnia could benefit by the inclusion of strategies dealing with emotional processes linked with sleep processes.

Why treat insomnia?

OBJECTIVE

To make the case that insomnia is better conceptualized, not as a symptom, but as a primary disorder.

DATA SOURCES

PubMed was searched from 1975-2009 using the search terms insomnia, insomnia and treatment, insomnia and cost, and insomnia and treatment and safety.

STUDY SELECTION

English-language articles and other materials were selected to address the following claims: insomnia is unremitting, insomnia is disabling, insomnia is costly, insomnia is pervasive, insomnia is pernicious, and insomnia treatment is safe and effective.

DATA EXTRACTION/SYNTHESIS

Insomnia, at least when chronic, should be conceptualized as a comorbid condition, one for which effective interventions are available.

CONCLUSIONS

It is speculated that treatment for insomnia will only become the norm when it has been demonstrated that treatment not only addresses the problem of insomnia but also serves to reduce medical and psychiatric morbidity. At that time, the question will no longer be "Why treat insomnia?" but instead "When isn't insomnia treatment indicated?"

The impact of sleep-related attentional bias on polysomnographically measured sleep in primary insomnia

STUDY OBJECTIVES

Although sleep-related attentional bias has been shown to be evident in primary insomnia, the association with objectively measured sleep has not been investigated. In the present study, we used polysomnography (PSG) to fill this void.

DESIGN

Patients with primary insomnia and healthy controls were studied using a visual dot probe task (VDP) and an emotional Stroop task (EST). Additionally, polysomnography was carried out in a sub-sample (n = 22) of patients in the subsequent night.

SETTING

Department of Psychiatry and Psychotherapy of the University of Freiburg Medical Center.

PARTICIPANTS

Thirty patients with primary insomnia and 30 matched healthy controls.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

Patients with primary insomnia demonstrated a significant sleep-related attentional bias compared to controls in the EST but no significant group effects were found for the VDP. VDP attentional bias scores were positively correlated with measures of sleep pressure, including total sleep time, sleep efficiency, and the amount of slow wave sleep. EST attentional bias scores were not correlated with subsequent PSG parameters, and we did not observe a correlation between attentional bias scores on the two tasks.

CONCLUSIONS

The unexpected relationship between increased attentional bias, in the VDP task, and improved markers of sleep duration and continuity, may be indicative of a homeostatic craving for sleep in those with high attentional bias. This awaits further testing in multiple night studies, to shed light on the mechanisms and implications of sleep-related attentional bias.

Night-to-night sleep variability in older adults with and without chronic insomnia

OBJECTIVES

(1) To quantify night-to-night variability in sleep behaviors and sleep measures among older chronic insomnia (CI) subjects and non-insomnia (NI) controls; (2) to investigate systematic temporal patterns of sleep behaviors and sleep measures across nights; and (3) to examine clinical correlates of sleep variability.

METHODS

Sixty-one older adults with CI (71.4years old, 67% F) and 31 older adults with NI (70.7years old, 65% F) completed questionnaires, kept sleep diaries and wore wrist actigraphs for 2 weeks. Mixed models were used to estimate within-subject mean and standard deviation values; these were then compared across groups. Mixed models were also used to determine associations across nights of sleep measures.

RESULTS

CI and NI differed on mean values for clinical ratings and sleep diary measures, but not for actigraphy measures. CI also showed significantly greater variability than NI on most sleep diary measures and on actigraphically measured wakefulness after sleep onset (WASO) and sleep efficiency. Among CI, neither diary nor actigraphy measures from one night correlated with values from the previous night. Diary WASO, sleep time, actigraphy sleep latency and sleep time, however, positively correlated with values from the previous two nights. Variability measures were not correlated with other global clinical measures among CI.

CONCLUSIONS

Compared to NI, older adults with CI report worse sleep and greater night-to-night variability, which was confirmed with actigraphy. There was little evidence for positive or negative correlation of sleep measures across nights. Variability of sleep may be an important target for insomnia treatments.

Neurobiological Mechanisms In Chronic Insomnia

This article grapples with the notion that insomnia can or should be defined in physiologic terms. It is proposed that insomnia is better understood from a neurobiological perspective. A review of the neurobiology of sleep and wakefulness is provided with a special emphasis on the implications for insomnia. Following the review it is suggested that a complete understanding of insomnia will require that the neurobiologic characterization of insomnia be informed by modern cognitive concepts and methods.

The role of personality traits in insomnia

Insomnia is a highly prevalent sleep disorder, known to affect psychological well-being and quality of life. While perpetuating factors have received much attention, the role of predisposing factors has not been studied in much detail. The susceptibility to develop insomnia may be linked to the presence of certain personality features. Here, we review studies that assessed this particular aspect of insomnia. Due to various methodological issues, definitive conclusions cannot be drawn as of yet, and several conflicting findings remain. However, there is a common trend indicating that insomniacs display more signs of 'neuroticism', 'internalization', anxious concerns and traits associated with perfectionism. These factors may play varying roles depending on the specific subdiagnosis of insomnia. In addition, certain personality traits may be related to the response to (cognitive) behavioral treatment. For instance, insomniacs reporting less 'guardedness' and have a higher score on the MMPI 'hypomania' scale show less improvement through psychological treatment. The specific role of personality traits in the etiology of insomnia is not yet clear, because of a lack of longitudinal data. Personality factors may play a causal role in the development of insomnia, but may also be a consequence of the sleep problem and the associated daytime dysfunction. Future longitudinal studies should not view personality as a single predisposing factor, but assess it as a part of a larger group of interacting psychological and physiological factors involved in the predisposition to and perpetuation of chronic insomnia.

Priming affects poor sleepers but not normal sleepers on an insomnia ambiguity task

With increasing importance being placed on the role of cognitive biases as a maintaining factor in insomnia, the influence of order effects on interpretative responses should be examined and subsequently accounted for. The aim of the present study was to examine whether asking participants about their sleep experiences, prior to testing for a perceptual bias, affects responses on a sleep-related ambiguity task. One hundred and seventeen undergraduate students, blind to the aims of the experiment, were issued either the Dysfunctional Beliefs and Attitudes to Sleep scale (DBAS-10) and Insomnia Severity Index (ISI) before, or following, completion of an Insomnia Ambiguity Task (IAT). As expected, a multivariate analysis of variance showed that the order in which participants completed the task affected the responses on the IAT with those given the DBAS-10 and ISI first, showing greater insomnia-related interpretations than those given the IAT first. However, on closer examination, this effect was evident only for those who were defined as poor sleepers, and that normal sleepers were largely unaffected by the order in which the tests are given. The results are discussed in terms of design and management of sleep-related research protocols involving implicit cognitive tasks.

Insomnias of childhood and adolescence

Childhood insomnias (CI) are a diverse group of sleep-related problems that present across the first 2 decades of life, ranging widely in severity. Little is understood about the origins of CI which are likely heterogeneous. Nevertheless, effective treatments for younger children have been shown to be efficacious. Defined within a development framework, this article reviews common correlates and causes of CI during the first two decades. A practical approach to the evaluation and treatment of insomnias among children and youth is presented.

Linking impulsivity to dysfunctional thought control and insomnia: a structural equation model

According to cognitive models of insomnia, excessive mental activity at bedtime may be viewed as an important impediment to the process of falling asleep. A further assumption of these models is that 'cognitive arousal' may be perpetuated and exacerbated by counterproductive strategies of thought management. As yet, little is known about factors that may predispose people to rely on these strategies when confronted with thoughts that keep them awake at night. This study examined the relations between impulsivity, use of different thought-control strategies and insomnia severity. A sample of 391 university students completed the UPPS Impulsive Behavior Scale, the Thought Control Questionnaire Insomnia-Revised and the Insomnia Severity Index. Correlation analyses revealed that two facets of impulsivity (urgency and lack of perseverance), two strategies of thought control (aggressive suppression and worry) and insomnia severity were positively associated. Follow-up structural equation modeling analyses showed that the two mentioned thought-control strategies mediated the effects of the two facets of impulsivity on sleep problems. These findings extend existing cognitive accounts of insomnia by suggesting how predisposing and perpetuating factors may be related: specific personality traits may incline individuals to respond with dysfunctional thought-control strategies to unwanted mental activity at night.

Prevalence and predictors of insomnia in women with invasive ovarian cancer: anxiety a major factor

The estimated prevalence of insomnia in cancer patients varies between 20% and 50%, which is substantially higher than the general population. To date, little is known about the risk factors for insomnia in patients with cancer. This study examines the prevalence and predictors of insomnia in a population-based sample of women with ovarian cancer. Participants were 772 women participating in the Australian Ovarian Cancer Study - Quality of Life Study. Insomnia was assessed using the Insomnia Severity Index (ISI). Demographic, disease and treatment variables, and psychosocial variables, including anxiety and depression, support care needs and social support and coping, were investigated as potential predictors of insomnia. Twenty-seven percent of women reported sub-clinical symptoms of insomnia (ISI score 8-14) and 17% reported clinically significant insomnia (ISI score 15-28). Three variables were significant predictors of clinically significant insomnia: young age (<50 years: Odds Ratio (OR)=2.36; Confidence Interval (CI) 1.06-5.26; 50-59 years: OR=2.73; CI 1.33-5.64) relative to 70+ years; higher unmet needs in the physical/daily living domain (OR=1.02; CI 1.01-1.03) and elevated anxiety (sub-clinical anxiety (Hospital Anxiety and Depression Scale (HADS) score 8-10): OR=1.83; CI 1.04-3.24; clinical anxiety (HADS score 11-21): OR=2.03; CI 1.08-3.85). In contrast to predictors of primary insomnia, women with cancer aged <60 years were more likely to report clinical levels of insomnia than women of 70+ years. Consistent with primary insomnia, elevated anxiety predicted insomnia in women with ovarian cancer. Given that both anxiety and insomnia are relatively common, and the relationship may potentially be bi-directional, the efficacy of interventions targeting insomnia and anxiety, rather than insomnia alone, is worthy of consideration.

The hyperarousal model of insomnia: a review of the concept and its evidence

Primary insomnia is defined as difficulties in falling asleep, maintaining sleep or non-restorative sleep accompanied by significantly impaired daytime functioning in the absence of a specific physical, mental or substance-related cause. The current review provides substantial support for the concept that hyperarousal processes from the molecular to the higher system level play a key role in the pathophysiology of primary insomnia. Autonomous, neuroendocrine, neuroimmunological, electrophysiological and neuroimaging studies demonstrate increased levels of arousal in primary insomnia during both night and daytime. In the light of neurobiological theories of sleep-wake regulation, primary insomnia may be conceptualized as a final common pathway resulting from the interplay between a genetic vulnerability for an imbalance between arousing and sleep-inducing brain activity, psychosocial/medical stressors and perpetuating mechanisms including dysfunctional sleep-related behavior, learned sleep preventing associations and other cognitive factors like tendency to worry/ruminate.

Metacognitive beliefs in primary insomnia: developing and validating the Metacognitions Questionnaire--Insomnia (MCQ-I)

Patients with Primary insomnia often experience intrusive, worrisome cognitive activity in the pre-sleep period. Metacognitive beliefs may explain this yet no valid reliable scale exists. The present study, therefore, developed the Metacognitions Questionnaire--Insomnia (MCQ-I). Following initial metacognitive insomnia profiling interviews, item refinement produced a preliminary 60-item MCQ-I. This was administered to 34 primary insomniacs and 37 normal sleepers. Psychometric data indicate primary insomniac patients score significantly higher than normal sleepers on MCQ-I. Test-retest reliability is good. Face, concurrent, construct and discriminant validity, scale sensitivity and specificity are all acceptable. Further research with larger primary insomnia and normal sleeper samples is now required.

The clock as a focus of selective attention in those with primary insomnia: an experimental study using a modified Posner paradigm

Espie and colleagues [(2006). The attention-intention-effort pathway in the development of psychophysiological insomnia: a theoretical review. Sleep Medicine Reviews, 10, 215-245] propose a route into psychophysiological insomnia along the attention-intention-effort pathway which focuses on the inhibition of sleep-wake automaticity. A contributing factor to this is selective attention to sleep (alongside explicit intention to sleep and effort in the sleep engagement process). Following on from previous work on selective attention to sleep [Marchetti, L. M., Biello, S. M., Broomfield, N. M., MacMahon, K. M. A., & Espie, C. A. (2006). Who is pre-occupied with sleep?. A comparison of attention bias in people with psychphysiological insomnia, delayed sleep phase syndrome and good sleepers using the induced change blindness paradigm. Journal of Sleep Research, 15, 212-221; MacMahon, K., Broomfield, N., Macphee, L., & Espie, C. A. (2006). Attention bias for sleep related stimuli in primary insomnia and delayed sleep phase syndrome using the dot-probe task. Sleep, 29, 11] and considering the importance of monitoring both internal and external cues in the maintenance of insomnia, as highlighted in the cognitive model of insomnia [Harvey, A. G. (2002). A cognitive model of insomnia. Behaviour Research and Therapy, 40, 869-893], a cognitive probe task was employed to investigate further the role of the clock as a focus of selective attention in those with primary insomnia. A 2 x 2 between participants design comparing reaction time of individuals with primary insomnia (n=22) and normal sleepers (n=22) on a modified Posner paradigm. Responses obtained from a computer task presenting times which fall within a normal sleep period were analysed. Individuals with primary insomnia demonstrated delayed disengagement to the clock (F(1,84)=6.9, p<0.05) which is taken as further support for previous research demonstrating that individuals with primary insomnia exhibit an attentional bias to sleep related stimuli. These results lend support to the attention-intention-effort model (Espie et al., 2006) and the cognitive model (Harvey, 2002) both of which recognise the importance of selective attention towards salient stimuli in the maintenance of insomnia. Possible clinical implications of attentional bias to sleep as a marker of psychopathology progression and treatment efficacy are discussed.

Dysfunctional beliefs and attitudes about sleep (DBAS): validation of a brief version (DBAS-16)

STUDY OBJECTIVE

Sleep related cognitions (e.g., faulty beliefs and appraisals, unrealistic expectations, perceptual and attention bias) play an important role in perpetuating insomnia. This paper presents new psychometric data on an abbreviated version of the Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS-16), a 16-item self-report measure designed to evaluate a subset of those sleep related cognitions.

DESIGN

Psychometric study of a patient-reported measure of sleep related beliefs based on existing clinical and research databases.

PARTICIPANTS

A total of 283 individuals (60% women; mean age of 46.6 years old) with insomnia, including 124 clinical patients and 159 research participants.

MEASUREMENTS AND RESULTS

Participants completed the DBAS, Insomnia Severity Index, Beck Depression and Anxiety Inventories, daily sleep diaries for 2 weeks, and 3 nights of polysomnography (research sample only) as part of a baseline assessment. The DBAS-16 was found to be reliable, as evidenced by adequate internal consistency (Cronbach alpha = 0.77 for clinical and 0.79 for research samples) and temporal stability (r = 0.83). The factor structure was similar to the original 30-item version, with 4 factors emerging and reflecting: (a) perceived consequences of insomnia, (b) worry/helplessness about insomnia, (c) sleep expectations, and (d) medication. DBAS total scores were significantly correlated with other self-report measures of insomnia severity, anxiety, and depression, but not with specific sleep parameters.

CONCLUSION

The psychometric qualities of this abbreviated DBAS-16 version seem adequate. This patient-reported measure should prove a useful instrument to evaluate the role of sleep related beliefs and attitudes in insomnia and to monitor change on this cognitive variable as a potential moderator of treatment outcome.

Is sleep really for sissies? Understanding the role of work in insomnia in the US

This study explores the role of work in patient narratives about their experiences with insomnia. "Work" includes such facets as the nature of one's occupation, the associated volume or amount of work required, mental demands related to work, work schedules and work-related stress. Interviews conducted with 24 patients aged between 22 and 74 receiving treatment for insomnia at one of two sleep medicine clinics in Oregon and Texas, USA, suggest that work is a pivotal influence in shaping interpretations of the nature of insomnia, its causes, and the efficacy of medical treatment. Results suggest correlations between sleeplessness and modern working lifestyles in American culture, in which labor seems to transcend the physical workplace, manifesting itself in the form of cognitive labor or continued problems into retirement. Patients often cite work as the primary causal agent in the development of their insomnia, their primary reason for needing "good" sleep, their impetus for seeking medical attention, and behavioral compliance with a medically prescribed regimen. Insomnia as an illness experience thus serves as a mechanism through which respondents consciously or unconsciously comment on the nature of work in their lives. The medical and social implications of these results are discussed.

Prospective comparison of subjective arousal during the pre-sleep period in primary sleep-onset insomnia and normal sleepers

Psychophysiological insomnia (PI) is the most common insomnia subtype, representing 12-15% of all sleep centre referrals. Diagnostic guidelines describe PI as an intrinsic sleep disorder involving both hyperarousal and learned sleep-preventing associations. Whilst evidence for the first component is reasonably compelling, evidence for learned (conditioned) sleep effects is markedly lacking. Indeed, to date no study has attempted to capture directly the conditioned arousal effect assumed to characterize the disorder. Accordingly, the present study explored variations in subjective arousal over time in 15 PI participants (sleep onset type) and 15 normal sleepers (NS). Self-report measures of cognitive arousal, somatic arousal and sleepiness were taken at three time points: 3 h before bedtime (early to mid-evening); 1 h before bedtime (late evening); and in the bedroom at lights out (bedtime) across four, 24-h cycles. Fluctuations in mean arousal and sleepiness values, and in day-to-day variation were examined using analyses of variance. Participants with PI were significantly more cognitive aroused and significantly less sleepy relative to NS, within the bedroom environment. These results support the tenet of conditioned mental arousal to the bedroom, although competing explanations cannot be ruled out. Results are discussed with reference to extant insomnia models.

Tinnitus and insomnia

Sleep problems are common in individuals with tinnitus but it is not known if they can be seen as a reaction to the acoustic percept of tinnitus disturbing normal sleep, or if there are common causes. Sleep problems further impair the quality of life of individuals with tinnitus and the impairment correlates with the severity of the tinnitus. However the nature of the relationship between tinnitus and disturbed sleep in individuals with tinnitus is not clearly understood. Preliminary studies suggest that chronically disturbed sleep (insomnia) in individuals with tinnitus that is not caused by organic disorders exists unrelated to the tinnitus. We studied the relationship between tinnitus and insomnia in a retrospective sleep study of 13 hospitalized patients with insomnia and tinnitus. Patients with sleep apnea, periodic leg movements, or a severe psychiatric disorder were excluded. We collected physiologic sleep measures (EEG, EOG, EMG, and respiration) and subjective sleep information from a morning protocol during two nights. We also obtained information about performance in sustained attention tasks and the scores of self-rated depression scale and self-rated daytime-tiredness scale. Thirteen age- and sex-matched inpatients with primary insomnia who did not have tinnitus served as controls. There were no significant differences between the physiologic data obtained in patients with tinnitus and in the controls. Both groups had low sleep efficiency but the patients with both insomnia and tinnitus had longer subjective sleep latencies than insomnia patients without tinnitus (controls). No differences were found in sustained attention tasks, subjective daytime tiredness, and depression rating scores between the two groups. Similarities between the results from these two groups suggest that sleep specific psychotherapeutic methods, which are established for treating insomnia, should be further developed for the use in patients with insomnia and tinnitus.