Stimulus control for insomnia: A systematic review and meta-analysis

Stimulus control (SC) is commonly viewed as an evidence-based treatment for insomnia, but it has not been evaluated comprehensively with modern review and meta-analytic techniques. The aim of the current study was thus to perform a systematic review and meta-analysis of trials that examine the efficacy of stimulus control for insomnia. A systematic search for eligible articles and dissertations was conducted in six online bibliographic databases. The 11 included studies, with the majority published between 1978 and 1998, were randomised controlled and experimental studies in adults, comparing stimulus control for insomnia with passive and active comparators and assessing insomnia symptoms as outcomes. A random effects model was used to determine the standardised mean difference Hedge's g at post-treatment and follow-up for three sleep diary measures: the number of awakenings, sleep onset latency, and total sleep time. A test for heterogeneity was conducted, forest plots were produced, the risk of publication bias was estimated, and the study quality was assessed. In the trials identified, stimulus control resulted in small to large improvements on sleep onset latency and total sleep time, relative to passive comparators (g = 0.38-0.85). Compared with active comparators, the improvements following stimulus control were negligible (g = 0.06-0.30). Although methodological uncertainties were observed in the included trials, stimulus control appears to be an efficacious treatment for insomnia when compared with passive comparators and with similar effects to active comparators. More robust studies are, however, warranted before stronger conclusions are possible to infer.

Characteristics of Patients with Subjective Sleep Problems after Cognitive Behavioral Therapy for Insomnia: Secondary Analyses of a Randomized Controlled Trial

Objective  Cognitive behavioral therapy for insomnia (CBT-I) is the first-line treatment for insomnia, but half of the patients do not reach remission. This study aimed to explore subjective remission by investigating the characteristics of patients who reported lingering sleep problems after CBT-I. Methods  Secondary analyses of a randomized controlled trial of group CBT-I in 72 primary care patients with insomnia disorder. Sociodemographic characteristics and outcomes (insomnia severity, sleep variables, hypnotics use, fatigue, depressive symptoms, and dysfunctional beliefs/attitudes), including baseline data and symptom change, were investigated in relation to patients' posttreatment response to the yes-or-no question "Would you say that you have sleep problems?" Results  A total of 56.9% of patients reported sleep problems after CBT-I. At baseline, they had worse depressive symptoms (14.9 (SD 7.5) vs. 10.2 (SD 5.9), p  = 0.006) and more awakenings (2.6 (SD 1.5) vs. 1.8 (SD 1.3), p  = 0.034) than those in subjective remission from sleep problems. Patients in the non-remission and remission groups showed similar improvements in sleep, fatigue, and depressive symptoms, but patients in the non-remission group had improved less in insomnia severity, dysfunctional beliefs/attitudes about sleep, and hypnotic use. In patients with more pronounced depressive symptoms before CBT-I, change in depressive symptoms during treatment partially explained subjective remission from sleep problems. Discussion  More severe depressive symptoms prior to CBT-I and less improvements in depressive symptoms during treatment predicted remaining subjective sleep problems after treatment. These findings highlight the importance of assessing depressive symptoms in primary care patients with insomnia, as patients with pronounced depressive symptoms may need tailored treatment.

A robot intervention for adults with ADHD and insomnia-A mixed-method proof-of-concept study

OBJECTIVE

To investigate individual effects of a three-week sleep robot intervention in adults with ADHD and insomnia, and to explore participants' experiences with the intervention.

METHODS

A proof-of-concept study with a mixed-methods design (n = 6, female = 4) where a repeated ABA single-case study was combined with interviews. Data were collected with the Consensus Sleep Diary, wrist actigraphy, questionnaires on symptoms of insomnia, arousal, emotional distress, and ADHD, and through individual interviews.

RESULTS

Visual analysis of the sleep diary and actigraphy variables did not support any effects from the robot intervention. Half of participants reported clinically relevant reductions on the Insomnia Severity Index from pre- to post-intervention. No changes regarding ADHD or arousal. Thematic analysis of the interviews resulted in three themes: (1) A pleasant companion, (2) Too much/not enough, and (3) A new routine.

CONCLUSION

Adjustments of the intervention ought to be made to match the needs of patients with both ADHD and insomnia before the next trial is conducted.

Sleep researchers' rankings of sleep journals

The impact factor is used to rank the quality of scientific journals but has been criticised for a number of reasons. The aim of the study was to investigate sleep researchers' perceptions of sleep journals to determine whether subjective rankings of journals were in line with the journals' impact factors. Clarivate's Journal Citation Reports website was used to identify journals containing the words 'sleep' or 'dream' in the titles with an impact factor since 2018, resulting in 12 journals. A survey including questions about how the respondent would rank these journals (e.g., three most prestigious journals) was developed. A total of 122 sleep researchers completed the survey. Sleep, Sleep Medicine Reviews and Journal of Sleep Research were ranked as the three most prestigious sleep journals, in line with the impact factors of the journals. For the rest of the journals, the subjective rankings and impact factors did not correspond as much.

Measurement properties of the minimal insomnia symptom scale (MISS) in adolescents

Background

The Minimal Insomnia Symptom Scale (MISS) is a three-item screening instrument that has been found to be psychometrically sound and capable of screening for insomnia among adults and older people. This study aimed to test the measurement properties of the MISS together with an additional item focusing on daytime functioning among adolescents using the Rasch measurement model.

Methods

A cross-sectional design was used, and data from adolescents (age 13–17 years, n = 3022) were analyzed using the Rasch measurement model.

Results

The MISS had good measurement properties. When adding the item “daytime disturbance”, the measurement properties deteriorated. When replacing the original MISS item “not rested by sleep” with the item “daytime disturbance”, the measurement properties slightly improved. We label this new scale the MISS-Revised (MISS-R). The reliability was better for the MISS-R (0.55) compared to the MISS (0.50). The optimal cut-off was found to be > 6 points, both for the MISS and the MISS-R.

Conclusions

This study provides general support that both the MISS as well as the MISS-R have good fit to the Rasch model. At this stage, neither the MISS nor the MISS-R can be advocated over the other for use among adolescents, although the MISS-R had slightly better reliability than the MISS. Additional studies are needed to determine the clinically optimal cut-score for identification of insomnia.

Contributory Factors for Teen Insomnia Symptoms: A Prospective Cohort Study in Sweden

Objectives

Insufficient sleep is a public health problem that impacts the mental and physical health of children and adolescents. Complaints of insomnia are particularly pervasive among adolescents. This longitudinal study investigates factors that contribute to teen insomnia symptoms.

Design

Five-year prospective follow-up study.

Setting

School-based.

Participants

A total of 522 children (49.8% girls) aged 9.4 ± 1.3 years at baseline; 14.4 ± 0.7 years at follow-up.

Measurements

The dependent variable of insomnia symptoms at follow-up was assessed with the Minimal Insomnia Symptom Scale-Revised. The independent variables at baseline were the perceived family financial situation, tiredness at school, problems waking up, short sleep duration, sleeping difficulties, having a bedroom Television (TV), and time spent with a TV/computer. Multivariate binary logistic regression analyses were used to examine whether the independent variables at baseline predicted insomnia symptoms at follow-up.

Results

Perceived quite bad/very bad family financial situation (OR 3.1; CI 1.4–6.7) and short sleep duration (<10 h) (OR 2.3; CI 1.0–5.3) among girls at baseline were associated with insomnia symptoms at follow-up. Having problems waking up among boys at baseline was associated with insomnia symptoms at follow-up (OR 4.9; CI 1.6–14.4).

Conclusion

Short sleep duration, problems waking up, and perceived bad family financial situation during childhood were linked with adolescent insomnia symptoms. The sex-based differences in these associations warrant further investigation to effectively mitigate adolescent insomnia.

A study of flotation-REST (restricted environmental stimulation therapy) as an insomnia treatment

Objectives

Flotation-REST is a treatment for deep relaxation, where a person is contained in a stimuli-restricted environment and floats in water with high salt content. The aim was to investigate the effects from flotation-REST on people with insomnia diagnosis, as previous studies of flotation-REST have demonstrated some effects on sleep but have limitations regarding sample selections and sleep measures.

Material and Methods

Six participants were recruited through an outpatient psychiatry clinic and posters on a university campus. All participants fulfilled criteria for insomnia diagnosis and four fulfilled criteria for major depressive disorder. Using a single case experimental design, daily changes were investigated on sleep logs regarding sleep onset latency (SOL), wake after sleep onset (WASO), total sleep time (TST), and sleep efficiency over the course of 12 sessions consisting of 45 min of flotation-REST. No other treatments were offered simultaneously. Questionnaire data on insomnia severity (the ISI) and depressive severity (the MADRS) were also collected.

Results

Three participants improved on their most salient insomnia symptom (long SOL or WASO), and two improved on sleep efficiency. The improvements were maintained 2 months after treatment. Insomnia severity decreased for three patients, whereas depressive severity decreased for five. No changes in TST were found and two patients did not improve on any sleep measure. The two participants who benefitted the most were students in their 20s.

Discussion

The results were mixed. Flotation-REST may be beneficial for young adults with sleep-onset insomnia but more research is warranted.

The effects of a sleep robot intervention on sleep, depression and anxiety in adults with insomnia - Study protocol of a randomized waitlist-controlled trial

Insomnia is a common sleep disorder characterized by difficulties initiating sleep, maintaining sleep and/or early-morning awakenings. Hyperarousal is a common causal and maintaining factor in insomnia models. Different techniques to decrease arousal have shown to be effective. Calm breathing can be one approach to enhance sleep. The Somnox sleep robot looks like a bean-shaped cushion to hug, and it gives physical and auditive guidance to calm down the users' breathing. There is currently no impartial empirical evidence of the sleep robot's effects on insomnia. This study is a randomized waitlist-controlled trial with a recruitment target of a minimum of 44 adults with insomnia and sleep disturbing arousal. Participants will complete pre-, mid- and post-intervention assessments, in addition to a 1-month follow-up. The primary outcome measure is the Insomnia Severity Index. Secondary sleep outcome measures are the Pre-Sleep Arousal Scale, a sleep diary and actigraphy. A secondary comorbid symptoms outcome measure is the Hospital Anxiety and Depression Scale. The main research question is whether treated participants have greater improvements regarding symptoms of insomnia post-intervention, compared with the waitlist control group. The analytic approach will be mixed-effects models. The current study will increase the knowledge on breath guidance as a way to reduce hyperarousal and enhance sleep. The sleep robot is a novel method and a potential treatment option for people with insomnia, when the recommended first-line treatments of Cognitive Behavioral Therapy and pharmaceuticals are inaccessible or undesirable. The ethics of healthcare robotics is discussed.

Paradoxical intention for insomnia: A systematic review and meta-analysis

Paradoxical intention (PI) has been considered an evidence-based treatment for insomnia since the 1990s, but it has not been evaluated with modern review techniques such as meta-analysis. The present study aimed to conduct the first systematic review and meta-analysis of studies that explore the effectiveness of PI for insomnia on insomnia symptomatology and theory-derived processes. A systematic review and meta-analysis was conducted by searching for eligible articles or dissertations in six online bibliographic databases. Randomised controlled trials and experimental studies comparing PI for insomnia to active and passive comparators and assessing insomnia symptoms as outcomes were included. A random effects model was estimated to determine the standardised mean difference Hedge's g at post-treatment. Test for heterogeneity was performed, fail-safe N was calculated, and study quality was assessed. The study was pre-registered at International Prospective Register of Systematic Reviews (PROSPERO, CRD42019137357). A total of 10 trials were identified. Compared to passive comparators, PI led to large improvements in key insomnia symptoms. Relative to active comparators, the improvements were smaller, but still moderate for several central outcomes. Compared to passive comparators, PI resulted in great reductions in sleep-related performance anxiety, one of several proposed mechanisms of change for PI. PI for insomnia resulted in marked clinical improvements, large relative to passive comparators and moderate compared to active comparators. However, methodologically stronger studies are needed before more firm conclusions can be drawn.

Treating co-morbid insomnia and social anxiety disorder with sequential CBT protocols: a single-case experimental study

BACKGROUND

Although insomnia disorder and social anxiety disorder are among the most prevalent psychiatric disorders, no studies have yet evaluated the use of sequential evidence-based treatment protocols in the population with co-morbid social anxiety disorder and insomnia disorder.

AIMS

This study aimed to investigate the effects of sequential treatments on co-morbid insomnia disorder and social anxiety disorder. As depression is a common co-morbid syndrome for both insomnia and social anxiety, a secondary aim was to examine depressive symptoms.

METHOD

A single-case repeated crossover AB design was used. Ten participants between 18 and 59 years of age with co-morbid DSM-5 diagnoses of insomnia disorder and social anxiety disorder received sequential treatments with cognitive behavioural therapy (CBT). Seven participants completed the treatment course. The primary outcomes were symptoms of insomnia and social anxiety, and the secondary outcome was symptoms of depression.

RESULTS

The effects of CBT on people with co-morbid social anxiety disorder and insomnia disorder were mixed. The majority of participants improved their sleep quality and lessened symptoms of social anxiety and depression. However, participants differed in their degree of improvement concerning all three disorders.

CONCLUSIONS

Sequential CBT treatments are potentially effective at decreasing symptoms of social anxiety and insomnia for people with co-morbid social anxiety disorder and insomnia disorder. The variation in outcome across participants makes firm conclusions about the treatment efficacy difficult to draw.

Sleep-Related Cognitive Processes and the Incidence of Insomnia Over Time: Does Anxiety and Depression Impact the Relationship?

Aim: According to the Cognitive Model of Insomnia, engaging in sleep-related cognitive processes may lead to sleep problems over time. The aim was to examine associations between five sleep-related cognitive processes and the incidence of insomnia, and to investigate if baseline anxiety and depression influence the associations. Methods: Two thousand three hundred and thirty-three participants completed surveys on nighttime and daytime symptoms, depression, anxiety, and cognitive processes at baseline and 6 months after the first assessment. Only those without insomnia at baseline were studied. Participants were categorized as having or not having incident insomnia at the next time point. Baseline anxiety and depression were tested as moderators. Results: Three cognitive processes predicted incident insomnia later on. Specifically, more safety behaviors and somatic arousal at Time 1 increased the risk of developing insomnia. When investigating changes in the cognitive processes over time, reporting an increase of worry and safety behaviors also predicted incident insomnia. Depressive symptoms moderated the association between changes in worry and incident insomnia. Conclusion: These findings provide partial support for the hypothesis that cognitive processes are associated with incident insomnia. In particular, safety behaviors, somatic arousal, and worry increase the risk for incident insomnia. Preventative interventions and future research are discussed.

Changes in insomnia as a risk factor for the incidence and persistence of anxiety and depression: a longitudinal community study

Background

The aim of this investigation was to examine the longitudinal association between change in insomnia status and the development of anxiety and depression in the general population.

Methods

A survey was mailed to 5000 randomly selected individuals (aged 18–70 years) in two Swedish counties. After 6 months, a follow-up survey was sent to those (n = 2333) who answered the first questionnaire. The follow-up survey was completed by 1887 individuals (80.9%). The survey consisted of questions indexing insomnia symptomatology, socio-demographic parameters, and the Hospital Anxiety and Depression Scale. Change in insomnia status was assessed by determining insomnia at the two time-points and then calculating a change index reflecting incidence (from non-insomnia to insomnia), remission (from insomnia to non-insomnia), or status quo (no change). Multivariate binary logistic regression analyses were used to examine the aim.

Results

Incident insomnia was significantly associated with an increased risk for the development of new cases of both anxiety (OR = 0.32, p < .05) and depression (OR = 0.43, p < .05) 6 months later. Incident insomnia emerged also as significantly associated with an elevated risk for the persistence of depression (OR = 0.30, p < .05), but not for anxiety.

Conclusions

This study extends previous research in that incidence in insomnia was shown to independently increase the risk for the development of anxiety and depression as well as for the maintenance of depression. The findings imply that insomnia may be viewed as a dynamic risk factor for anxiety and depression, which might have implications for preventative work.

Insomnia in Relation to Academic Performance, Self-Reported Health, Physical Activity, and Substance Use Among Adolescents

Purpose: Insomnia affects up to one in four adolescents and has been shown to have a negative impact on their mental and physical health. This study aimed to investigate the association between insomnia, academic performance, self-reported health, physical activity, school start time, and substance use among adolescents. Methods: A survey with a cross-sectional design was completed by adolescents (15–17 years old; n = 1504) in southern Sweden. The Minimal Insomnia Symptoms Scale (MISS) was used to operationalize insomnia. A multiple logistic regression analysis was used to analyze the relationship between insomnia and self-reported health, failed school courses, substance use, school start time, family financial situation, screen time, and gender. Results: Insomnia (MISS ≥ 6) was associated with poor self-reported health (OR: 4.35), failed school courses (OR: 1.47), and use of alcohol and/or cigarettes (OR: 1.43). When the combined effect of self-reported health and physical activity were investigated, a combination of low physical activity (≤1 time/week) and poor self-reported health was strongly associated with insomnia (OR: 18.87). Conclusions: Insomnia was associated with other problems that in themselves are risk factors for poor health. This highlights the need for a holistic health-promoting approach to prevent insomnia, such as efforts to promote physical activity, school success, and the reduction of alcohol/cigarette use.

Facilitators and Barriers for a Good Night's Sleep Among Adolescents

Background

Sleep deprivation among adolescents is a major public health issue. Although previous studies have described their sleep habits and the consequences thereof, the voices of adolescents themselves are rarely heard. The aim of this study was to investigate adolescents’ experiences regarding what they perceived as facilitators and barriers for a good night’s sleep.

Methods

A qualitative focus group study with Swedish adolescents (n = 45) aged 16–18 years was performed with seven focus groups and analyzed using qualitative content analysis.

Results

Three categories were identified in the analysis regarding facilitators and barriers for achieving a good night’s sleep: (1) Striving for a sense of well-being, (2) Tiring yourself out, and (3) Regulating electronic media availability. The adolescents thought that sleep was important in order to be able to cope with everyday life and to allow physical recovery. Overall, the adolescents were knowledgeable regarding commonly recommended strategies for improving sleep, but they had trouble finding a balance between sleep and other activities. Electronic media was used to obtain a sense of belonging and to communicate with others, which in itself was described as important for the adolescents’ well-being. However, communicating with friends and family during the night conflicted with achieving a good night’s sleep. Parental behaviors (late work habits, internet rules) were also perceived as important for adolescents’ sleep habits.

Conclusions

An understanding of the dilemma of finding a balance between sleep and other activities may aid future sleep-promoting interventions for adolescents, incorporating the impact from social factors’ on the adolescents’ sleep.

Adolescents' Experiences of Staying Overnight at Family-Centered Pediatric Wards

Background

Sleep is essential for health and recovery. Hospital stays may affect adolescents' sleep quality negatively as routines in the ward are not adapted for adolescents' developmental status or sleep habits. The aims with this study were to (a) explore and describe how adolescents experience sleep in the family-centered pediatric ward, (b) explore and describe how adolescents experience the presence or absence of a parent during the hospital stay, and (c) identify circumstances that the adolescents describe as influential of their sleep in the pediatric wards.

Methods

This is a qualitative interview study employing thematic analysis with an inductive and exploratory approach. Sixteen adolescents aged between 13 and 17 years participated in the study.

Results

Three themes were found: the importance of good sleep, safety as a prerequisite for sleep in hospital, and circumstances influencing adolescents' sleep in hospital.

Conclusion

The adolescents described their sleep at the pediatric ward positively, but mentioned disturbing factors associated with pain, nightly check-ups, noises, and inactivity. Parental presence was perceived as very positive both during the night and the day.

Child and adolescent sleep duration recommendations in relation to psychological and somatic complaints based on data between 1985 and 2013 from 11 to 15 year-olds

PURPOSE

To investigate the association between sleep duration, sleep initiation difficulties and psychological and somatic complaints.

METHODS

We used three cohorts of cross-sectional Swedish questionnaire data, from the Health Behaviours of School aged Children (1985/1986, 2005/2006, 2013/2014, n=>18 000, aged 11-15). Specific complaints (e.g. pain) and total complaint load were used as outcomes of sleep duration, sleep initiation difficulties and the combination of them both.

RESULTS

Sleeping less than recommended and sleep initiation difficulties were associated with increased odds of specific complaints and belonging to the group with the greatest complaint load. The combination of short sleep duration and sleep initiation difficulties were associated with higher odds than either sleep issue alone. No interaction effects between time and sleep variables were found regarding complaints.

CONCLUSIONS

The findings support recent sleep duration recommendations. Further, sleep issues warrant a broad health assessment as they indicate a high likelihood of other complaints.

Changes in sleep habits between 1985 and 2013 among children and adolescents in Sweden

Aims: The aim was to investigate changes in child and adolescent sleep habits in Sweden over time. This had not been done previously. Methods: Cross-sectional questionnaire data over three decades of investigations of the Health Behaviours of School Children study (1985/1986, 2005/2006 and 2013/2014) were used. The sample included 18,682 children and adolescents, aged 11, 13 and 15. Empirically based age-specific sleep duration recommendations were used to operationalise sleep duration. Results: The results showed that, over time, fewer go to bed early and more go to bed late. Regarding sleep duration, there have been decreases in the proportion of children and adolescents that sleep as much as is recommended for their age. Sleep onset difficulties have increased for all ages and increase the odds of sleeping less than recommended as well as having late bedtimes. Boys were more likely than girls to have later bedtimes and to sleep less than recommended. A vocational educational track, not planning to study further or being unsure of which track to choose increased the odds for 15 year olds to have late bedtimes and to sleep less than recommended compared with a college preparatory track. Conclusions: The results indicate that over time, fewer children and adolescents attain sufficient sleep duration. This may have implications for study results, mental health and cognitive abilities.

Cognitive Behavioural Therapy for Insomnia in Psychiatric Disorders

Insomnia means difficulties in initiating or maintaining sleep and is commonly comorbid with psychiatric disorders. From being considered secondary to primary psychiatric disorders, comorbid insomnia is now considered an independent health issue that warrants treatment in its own right. Cognitive behavioural therapy for insomnia (CBT-I) is an evidence-based treatment for insomnia. The effects from CBT-I on comorbid psychiatric conditions have received increasing interest as insomnia comorbid with psychiatric disorders has been associated with more severe psychiatric symptomologies, and there are studies that indicate effects from CBT-I on both insomnia and psychiatric symptomology. During recent years, the literature on CBT-I for comorbid psychiatric groups has expanded and has advanced methodologically. This article reviews recent studies on the effects from CBT-I on sleep, daytime symptoms and function and psychiatric comorbidities for people with anxiety, depression, bipolar disorder, psychotic disorders and post-traumatic stress disorder. Future strategies for research are suggested.

The role of psychiatric and somatic conditions in incidence and persistence of insomnia: a longitudinal, community study

OBJECTIVE

The objective was to investigate the role of psychiatric and somatic conditions in incident and persistent insomnia.

DESIGN

This was a prospective study with 3 measurement points over 1.5years.

SETTING

The participants were sent a survey to their home addresses.

PARTICIPANTS

A survey was sent out to 5000 random individuals (18-70 years) in 2 Swedish counties. To those who returned the baseline questionnaire (n=2333), 2 follow-up surveys (6 and 18months later) were sent out and completed by 1887 and 1795 individuals, respectively.

MEASUREMENTS

The survey contained questions about sociodemographic factors and insomnia symptomatology, the Hospital Anxiety and Depression Scale, and items assessing 12 forms of somatic conditions (eg, heart disease and headache).

RESULTS

Baseline depression, headache, and number of psychiatric and somatic conditions were found to be independent risk factors for incident insomnia. Also, deterioration in depression and heart disease status and increased number of conditions over time increased the risk for insomnia incidence. Anxiety; depression; pain in neck, back, or shoulders; and headache at baseline were found to significantly discriminate between those with persistent insomnia and those with persistent normal sleep. Those with persistent insomnia also reported a higher number of conditions relative to those with persistent normal sleep. None of the psychiatric or somatic conditions were found to be associated with persistence of insomnia relative to remission of insomnia.

CONCLUSION

The current study suggests that both psychiatric and somatic conditions are involved in the incidence but not in the persistence of insomnia. Clinical and theoretical implications of the results are discussed.

Associations between psychological factors and nighttime/daytime symptomatology in insomnia

PURPOSE

The aim of this study was to examine psychological factors in insomnia and the association between psychological mechanisms and nighttime and daytime symptoms.

METHODS

A cross-sectional examination in the general population was used. The study sample consisted of 1890 participants from the general population. The participants completed a survey on nighttime and daytime symptoms, health outcomes, and psychological factors.

RESULTS

Relative to poor and normal sleepers, the insomnia group had higher scores on worry, beliefs, physiologic arousal, monitoring/attentional bias, and safety behaviors than the other two groups, and the poor sleepers exhibited a similar pattern relative to the normal sleepers. High total wake time was associated with more worry, physiologic arousal, and safety behaviors (26.3% variance), low sleep restoration with more worry, unhelpful beliefs, and monitoring/attentional bias (28.2% variance), and low sleep quality with higher scores on all the psychological mechanisms (35.8% variance). Elevated daytime symptoms were related to more unhelpful beliefs and monitoring/attentional bias (44.3% variance).

CONCLUSION

The findings indicate that psychological factors are linked to nighttime and daytime symptomatology in insomnia.

Psychometric properties of the Pre-Sleep Arousal Scale in a large community sample

OBJECTIVE

The purpose was to examine the psychometric properties of the Pre-Sleep Arousal Scale.

METHODS

From a randomly selected sample of the general population (N=5000), 2327 participants completed a survey on nighttime symptoms, daytime symptoms, health outcomes, and psychological processes. The study sample consisted of 1890 participants who did not fulfill criteria for a sleep disorder other than insomnia.

RESULTS

Findings indicated that the PSAS did not produce an adequate factorial solution. When three problematic items were removed, the solution, accounting for 48.5% of the variance, improved (PSAS-13). One subscale, cognitive arousal (α=.88), consisted of five items (37.1%), and one subscale, somatic arousal (α=.72), of eight items (11.4%). The two factors were significantly inter-correlated (ρ=.51) and associated with the PSAS-13 (ρ=.91, ρ=.80). Among those with insomnia, a shortened PSAS (PSAS-14) was established, which consisted of a cognitive and a somatic subscale (48.6% of the variance). The PSAS-13 and the two subscales showed discriminant validity between three sleep groups (normal sleep, poor sleep, and insomnia disorder) (R(2)=.24-.34). The PSAS-13 and the subscales demonstrated convergent validity with measures on sleep-related worry, sleep-related beliefs, anxiety, and depression. The PSAS-13 and the two subscales were significantly correlated with sleep parameters and daytime impairment.

CONCLUSION

Though acceptable psychometric properties were established for the PSAS, the cognitive subscale's focus upon general pre-sleep arousal and the relatively low variance accounted for calls for further work on and a possible re-conceptualization of the PSAS.