Cognitive behavioral therapy vs zopiclone for treatment of chronic primary insomnia in older adults: a randomized controlled trial

CONTEXT

Insomnia is a common condition in older adults and is associated with a number of adverse medical, social, and psychological consequences. Previous research has suggested beneficial outcomes of both psychological and pharmacological treatments, but blinded placebo-controlled trials comparing the effects of these treatments are lacking.

OBJECTIVE

To examine short- and long-term clinical efficacy of cognitive behavioral therapy (CBT) and pharmacological treatment in older adults experiencing chronic primary insomnia.

DESIGN, SETTING, AND PARTICIPANTS

A randomized, double-blinded, placebo-controlled trial of 46 adults (mean age, 60.8 y; 22 women) with chronic primary insomnia conducted between January 2004 and December 2005 in a single Norwegian university-based outpatient clinic for adults and elderly patients.

INTERVENTION

CBT (sleep hygiene, sleep restriction, stimulus control, cognitive therapy, and relaxation; n = 18), sleep medication (7.5-mg zopiclone each night; n = 16), or placebo medication (n = 12). All treatment duration was 6 weeks, and the 2 active treatments were followed up at 6 months.

MAIN OUTCOME MEASURES

Ambulant clinical polysomnographic data and sleep diaries were used to determine total wake time, total sleep time, sleep efficiency, and slow-wave sleep (only assessed using polysomnography) on all 3 assessment points.

RESULTS

CBT resulted in improved short- and long-term outcomes compared with zopiclone on 3 out of 4 outcome measures. For most outcomes, zopiclone did not differ from placebo. Participants receiving CBT improved their sleep efficiency from 81.4% at pretreatment to 90.1% at 6-month follow-up compared with a decrease from 82.3% to 81.9% in the zopiclone group. Participants in the CBT group spent much more time in slow-wave sleep (stages 3 and 4) compared with those in other groups, and spent less time awake during the night. Total sleep time was similar in all 3 groups; at 6 months, patients receiving CBT had better sleep efficiency using polysomnography than those taking zopiclone.

CONCLUSION

These results suggest that interventions based on CBT are superior to zopiclone treatment both in short- and long-term management of insomnia in older adults.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT00295386.

Individual differences in tolerance to shift work--a systematic review

Shift work tolerance is a term describing the ability to adapt to shift work without adverse consequences. In this paper we systematically review literature published investigating the relation between individual differences such as age, gender, personality, morningness/eveningness as well as biological variables and different measures of shift work tolerance from 1998 till 2009. A total of 60 articles were included in this review, of which ten studies were classified as longitudinal, while the rest were classified as cross-sectional. Overall, the studies indicate that young age, male gender, low scores on morningness, high scores on flexibility and low scores on languidity, low scores on neuroticism, high scores on extraversion and internal locus of control and some genetic dispositions are related to higher shift work tolerance. More longitudinal studies, especially concerning personality, are needed to make conclusions about the predictive power of individual differences for shift work tolerance.

Sleep and depression in postpartum women: a population-based study

STUDY OBJECTIVES

(1) To describe the prevalence of and risk factors for postpartum maternal sleep problems and depressive symptoms simultaneously, (2) identify factors independently associated with either condition, and (3) explore associations between specific postpartum sleep components and depression.

DESIGN

Cross-sectional.

SETTING

Population-based.

PARTICIPANTS

All women (n = 4191) who had delivered at Stavanger University Hospital from October 2005 to September 2006 were mailed a questionnaire seven weeks postpartum. The response rate was 68% (n = 2830).

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Sleep was measured using the Pittsburgh Sleep Quality Index (PSQI), and depressive symptoms using the Edinburgh Postnatal Depression Scale (EPDS). The prevalence of sleep problems, defined as PSQI > 5, was 57.7%, and the prevalence of depression, defined as EPDS > or = 10, was 16.5%. The mean self-reported nightly sleep duration was 6.5 hours and sleep efficiency 73%. Depression, previous sleep problems, being primiparous, not exclusively breastfeeding, or having a younger or male infant were factors associated with poor postpartum sleep quality. Poor sleep was also associated with depression when adjusted for other significant risk factors for depression, such as poor partner relationship, previous depression, depression during pregnancy and stressful life events. Sleep disturbances and subjective sleep quality were the aspects of sleep most strongly associated with depression.

CONCLUSIONS

Poor sleep was associated with depression independently of other risk factors. Poor sleep may increase the risk of depression in some women, but as previously known risk factors were also associated, mothers diagnosed with postpartum depression are not merely reporting symptoms of chronic sleep deprivation.

Effects of chronic mild stress on sexual behavior, locomotor activity and consumption of sucrose and saccharine solutions

Many symptoms of human depressive disorders are also observed in animals after exposure to unpredictable stressors. The chronic mild stress (CMS) paradigm was developed in order to better model the human situation by using chronic mild stressors over a longer period. It is claimed that the model induces anhedonia in the animals, a core symptom of depression in humans. Despite the fact that the CMS model has a high degree of face validity, there are a number of laboratories in which the establishment of the model is less reliably observed. We have examined behavior (sexual activity and open field activity) together with hedonic measures (sucrose and saccharine intake) after exposure to CMS. CMS decreased male sexual activity (e.g. reduced capability to ejaculate) and increased activity in an open field test. The hedonic measures showed diverging results after CMS in our laboratory. Sucrose consumption was reduced, while saccharine consumption did not show a comparable change. It is concluded that CMS induces comparable alterations to some depression-like symptoms in humans. Saccharine consumption is not a reliable indicator of the hedonic responsiveness to CMS.

The association between sleep duration, body mass index and metabolic measures in the Hordaland Health Study

Several studies show that short self-reported sleep duration is associated with elevated body mass index (BMI). Short sleep duration may change appetite hormones, but whether this also influences metabolic measures like cholesterol and triglycerides is less clear. Furthermore, obesity is linked to increases in blood pressure, and recently, short sleep duration has been shown to be an independent risk factor for hypertension. This is a population-based cross-sectional study (The Hordaland Health Study). A subgroup of 8860 subjects, aged 40-45 years, answered a sleep questionnaire. Body weight, height and blood pressure were measured, and non-fasting blood samples were collected and analyzed for total cholesterol, HDL-cholesterol and triglycerides. Sleep duration was divided into the following subgroups: < 5, 5-5.99, 6-6.99, 7-7.99, 8-8.99 and > or = 9 h. The results show that short sleep duration was associated with elevated BMI and increased prevalence of obesity. Similar to BMI, levels of cholesterol, triglycerides, systolic and diastolic blood pressure were higher in subjects with short sleep duration. This co-variation seemed to be attributed to variables like gender, smoking and BMI. In conclusion, our study confirms a clear association between short sleep duration and elevated BMI and obesity. Furthermore, levels of total cholesterol, HDL-cholesterol, triglycerides and blood pressure were associated with sleep duration.

Serotonin and the sleep/wake cycle: special emphasis on microdialysis studies

Several areas in the brainstem and forebrain are important for the modulation and expression of the sleep/wake cycle. Even if the first observations of biochemical events in relation to sleep were made only 40 years ago, it is now well established that several neurotransmitters, neuropeptides, and neurohormones are involved in the modulation of the sleep/wake cycle. Serotonin has been known for many years to play a role in the modulation of sleep, however, it is still very controversial how and where serotonin may operate this modulation. Early studies suggested that serotonin is necessary to obtain and maintain behavioral sleep (permissive role on sleep). However, more recent microdialysis experiments provide evidence that the level of serotonin during W is higher in most cortical and subcortical areas receiving serotonergic projections. In this view the level of extracellular serotonin would be consistent with the pattern of discharge of the DRN serotonergic neurons which show the highest firing rate during W, followed by a decrease in slow wave sleep and by virtual electrical silence during REM sleep. This suggests that during waking serotonin may complement the action of noradrenaline and acetylcholine in promoting cortical responsiveness and participate to the inhibition of REM-sleep effector neurons in the brainstem (inhibitory role on REM sleep). The apparent inconsistency between an inhibitory and a facilitatory role played by serotonin on sleep has at least two possible explanations. On the one hand serotonergic modulation on the sleep/wake cycle takes place through a multitude of post-synaptic receptors which mediate different or even opposite responses; on the other hand the achievement of a behavioral state depends on the complex interaction between the serotonergic and other neurotransmitter systems. The main aim of this commentary is to review the role of brain serotonin in relation to the sleep/wake cycle. In particular we highlight the importance of microdialysis for on-line monitoring of the level of serotonin in different areas of the brain across the sleep/wake cycle.

The European Insomnia Guideline: An update on the diagnosis and treatment of insomnia 2023

Progress in the field of insomnia since 2017 necessitated this update of the European Insomnia Guideline. Recommendations for the diagnostic procedure for insomnia and its comorbidities are: clinical interview (encompassing sleep and medical history); the use of sleep questionnaires and diaries (and physical examination and additional measures where indicated) (A). Actigraphy is not recommended for the routine evaluation of insomnia (C), but may be useful for differential-diagnostic purposes (A). Polysomnography should be used to evaluate other sleep disorders if suspected (i.e. periodic limb movement disorder, sleep-related breathing disorders, etc.), treatment-resistant insomnia (A) and for other indications (B). Cognitive-behavioural therapy for insomnia is recommended as the first-line treatment for chronic insomnia in adults of any age (including patients with comorbidities), either applied in-person or digitally (A). When cognitive-behavioural therapy for insomnia is not sufficiently effective, a pharmacological intervention can be offered (A). Benzodiazepines (A), benzodiazepine receptor agonists (A), daridorexant (A) and low-dose sedating antidepressants (B) can be used for the short-term treatment of insomnia (≤ 4 weeks). Longer-term treatment with these substances may be initiated in some cases, considering advantages and disadvantages (B). Orexin receptor antagonists can be used for periods of up to 3 months or longer in some cases (A). Prolonged-release melatonin can be used for up to 3 months in patients ≥ 55 years (B). Antihistaminergic drugs, antipsychotics, fast-release melatonin, ramelteon and phytotherapeutics are not recommended for insomnia treatment (A). Light therapy and exercise interventions may be useful as adjunct therapies to cognitive-behavioural therapy for insomnia (B).

Chronic mild stress inhibits BDNF protein expression and CREB activation in the dentate gyrus but not in the hippocampus proper

Chronic stress is linked to development of depression and may trigger neurobiological changes underlying the disease. Downregulation of the secretory peptide brain-derived neurotrophic factor (BDNF) and the transcriptional regulator calcium/cyclic-AMP responsive binding protein (CREB) have been implicated in stress and depression-related pathology in animal studies. When animals are exposed to the chronic mild stress (CMS) protocol, multiple depression-like symptoms are observed. Here we investigated the effect of CMS on BDNF protein expression and CREB activation in the dentate gyrus and hippocampus proper. Rats exposed for 5 weeks to repeated, unpredictable, mild stressors showed reduced BDNF expression and inhibited phosphorylation of CREB (Ser-133) in the dentate gyrus (-25.0%+/-3.5% and -29.7+/-7.3%, respectively), whereas no significant effects were observed in the hippocampus proper. CMS-treated rats consumed less sucrose compared to control rats, indicating a state of anhedonia. Moreover, phospho-CREB levels in the dentate gyrus were positively correlated with the animals' sucrose intake at the end of the CMS protocol. These results couple chronic mild stress to a downregulation of CREB activity and BDNF protein expression specifically within the dentate gyrus and support the possibility that the BDNF-CREB system plays an important role in the response to environmental challenges.

The association between use of electronic media in bed before going to sleep and insomnia symptoms, daytime sleepiness, morningness, and chronotype

This study investigated whether the use of a television, computer, gaming console, tablet, mobile phone, or audio player in bed before going to sleep was associated with insomnia, daytime sleepiness, morningness, or chronotype. 532 students aged 18-39 were recruited from lectures or via e-mail. Respondents reported the frequency and average duration of their in-bed media use, as well as insomnia symptoms, daytime sleepiness, morningness-eveningness preference and bedtime/rise time on days off. Mean time of media use per night was 46.6 minutes. The results showed that computer usage for playing/surfing/reading was positively associated with insomnia, and negatively associated with morningness. Mobile phone usage for playing/surfing/texting was positively associated with insomnia and chronotype, and negatively associated with morningness. None of the other media devices were related to either of these variables, and no type of media use was related to daytime sleepiness.

Insomnia, anxiety, and depression during the COVID-19 pandemic: an international collaborative study

IMPORTANCE AND STUDY OBJECTIVE

The COVID-19 pandemic has produced unprecedented changes in social, work, and leisure activities, which all have had major impact on sleep and psychological well-being. This study documented the prevalence of clinical cases of insomnia, anxiety, and depression and selected risk factors (COVID-19, confinement, financial burden, social isolation) during the first wave of the pandemic in 13 countries throughout the world.

DESIGN AND PARTICIPANTS

International, multi-center, harmonized survey of 22 330 adults (mean age = 41.9 years old, range 18-95; 65.6% women) from the general population in 13 countries and four continents. Participants were invited to complete a standardized web-based survey about sleep and psychological symptoms during the first wave of the COVID-19 pandemic from May to August 2020.

RESULTS

Clinical insomnia symptoms were reported by 36.7% (95% CI, 36.0-37.4) of respondents and 17.4% (95% CI, 16.9-17.9) met criteria for a probable insomnia disorder. There were 25.6% (95% CI, 25.0-26.2) with probable anxiety and 23.1% (95% CI, 22.5-23.6) with probable depression. Rates of insomnia symptoms (>40%) and insomnia disorder (>25%) were significantly higher in women, younger age groups, and in residents of Brazil, Canada, Norway, Poland, USA, and United Kingdom compared to residents from Asian countries (China and Japan, 8% for disorder and 22%-25% for symptoms) (all Ps < 0.01). Proportions of insomnia cases were significantly higher among participants who completed the survey earlier in the first wave of the pandemic relative to those who completed it later. Risks of insomnia were higher among participants who reported having had COVID-19, who reported greater financial burden, were in confinement for a period of four to five weeks, and living alone or with more than five people in same household. These associations remained significant after controlling for age, sex, and psychological symptoms.

CONCLUSION AND RELEVANCE

Insomnia, anxiety, and depression were very prevalent during the first wave of the COVID-19 pandemic. Public health prevention programs are needed to prevent chronicity and reduce long-term adverse outcomes associated with chronic insomnia and mental health problems.

A 10-year trend of insomnia prevalence in the adult Norwegian population

OBJECTIVE

We aimed to investigate the 10-year trend in the prevalence of insomnia symptoms, insomnia cases, and use of hypnotic agents in the adult Norwegian population.

METHODS

Data from two representative surveys assessing identical insomnia symptoms in the adult population of Norway, one conducted in 1999-2000 (N=2001) and one conducted in 2009-2010 (N=2000), were compared.

RESULTS

Controlling for basic demographic variables, significant increases were found over the 10-year study period in the prevalence of sleep-onset insomnia from 13.1% to 15.2%, dissatisfaction with sleep from 8.2% to 13.6%, daytime impairment from 14.8% to 18.8%, Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV) insomnia cases from 11.9% to 15.5%, and hypnotic agent use from 6.9% to 11.1%. No secular trend was found for maintenance insomnia or for early morning awakening insomnia. Across the two surveys, women reported a higher prevalence of insomnia than men. Age was positively associated with the prevalence of nocturnal sleep problems and use of hypnotic agents but was inversely associated with daytime impairment. Individuals with low socioeconomic status (SES) reported a higher prevalence of several insomnia symptoms.

CONCLUSIONS

Insomnia seems to be on the rise in the general adult population, which gives reason for concern. Prevention of insomnia and cost-effective interventions should receive higher priority in the future.

Shift work disorder in nurses--assessment, prevalence and related health problems

BACKGROUND

This study investigates the prevalence of symptoms of shift work disorder in a sample of nurses, and its association to individual, health and work variables.

METHODOLOGY/PRINCIPAL FINDINGS

We investigated three different shift work disorder assessment procedures all based on current diagnostic criteria and employing symptom based questions. Crude and adjusted logistic regression analyses were performed with symptoms of shift work disorder as the dependent variable. Participants (n = 1968) reported age, gender, work schedule, commuting time, weekly work hours, children in household, number of nights and number of shifts separated by less than 11 hours worked the last year, use of bright light therapy, melatonin and sleep medication, and completed the Bergen Insomnia Scale, Epworth Sleepiness Scale, Global Sleep Assessment Questionnaire, Diurnal Scale, Revised Circadian Type Inventory, Dispositional Resilience (Hardiness) Scale--Revised, Fatigue Questionnaire, questions about alcohol and caffeine consumption, as well as the Hospital Anxiety and Depression Scale.

CONCLUSIONS/SIGNIFICANCE

Prevalence rates of symptoms of shift work disorder varied from 32.4-37.6% depending on the assessment method and from 4.8-44.3% depending on the work schedule. Associations were found between symptoms of shift work disorder and age, gender, circadian type, night work, number of shifts separated by less than 11 hours and number of nights worked the last year, insomnia and anxiety. The different assessment procedures yielded similar results (prevalence and logistic regression analyses). The prevalence of symptoms indicative of shift work disorder was high. We argue that three symptom-based questions used in the present study adequately assess shift work disorder in epidemiological studies.

Insomnia, excessive sleepiness, excessive fatigue, anxiety, depression and shift work disorder in nurses having less than 11 hours in-between shifts

Study objective

To assess if less than 11 hours off work between work shifts (quick returns) was related to insomnia, sleepiness, fatigue, anxiety, depression and shift work disorder among nurses.

Methods

A questionnaire including established instruments measuring insomnia (Bergen Insomnia Scale), sleepiness (Epworth Sleepiness Scale), fatigue (Fatigue Questionnaire), anxiety/depression (Hospital Anxiety and Depression Scale) and shift work disorder was administered. Among the 1990 Norwegian nurses who participated in the study; 264 nurses had no quick returns, 724 had 1–30 quick returns and 892 had more than 30 quick returns during the past year. 110 nurses did not report the number of quick returns during the past year. The prevalence of insomnia, excessive sleepiness, excessive fatigue, anxiety, depression and shift work disorder was calculated within the three groups of nurses. Crude and adjusted logistic regression analyses were performed to assess the relation between quick returns and such complaints.

Results

We found a significant positive association between quick returns and insomnia, excessive sleepiness, excessive fatigue and shift work disorder. Anxiety and depression were not related to working quick returns.

Conclusions

There is a health hazard associated with quick returns. Further research should aim to investigate if workplace strategies aimed at reducing the number of quick returns may reduce complaints among workers.

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.

Sleep, circadian rhythms, and athletic performance

Sleep deprivation and time of day are both known to influence performance. A growing body of research has focused on how sleep and circadian rhythms impact athletic performance. This review provides a systematic overview of this research. We searched three different databases for articles on these issues and inspected relevant reference lists. In all, 113 articles met our inclusion criteria. The most robust result is that athletic performance seems to be best in the evening around the time when the core body temperature typically is at its peak. Sleep deprivation was negatively associated with performance whereas sleep extension seems to improve performance. The effects of desynchronization of circadian rhythms depend on the local time at which performance occurs. The review includes a discussion of differences regarding types of skills involved as well as methodological issues.

Prevalence and correlates of delayed sleep phase in high school students

PURPOSE

To investigate prevalence and correlates of delayed sleep phase, characterized by problems falling asleep in the evening and rising at adequate times in the morning, in a large sample of Norwegian high school students.

METHODS

A randomized sample of 1285 high school students (aged 16-19 years) participated in an internet based study answering questions about sleep habits, height, weight, smoking, alcohol use, school grades, and anxiety and depression symptoms. Delayed sleep phase was operationalized as difficulties falling asleep before 2 a.m. at least three nights per week together with much or very much difficulty waking up in the morning.

RESULTS

The results show a prevalence of delayed sleep phase of 8.4%. In all, 68% of these students (5.7% of the total sample) also reported problems advancing their sleep period as well as one daytime consequence (oversleeping at least two days a week or experiencing much/very much sleepiness at school). Delayed sleep phase was associated with lower average school grades, smoking, alcohol usage, and elevated anxiety and depression scores.

CONCLUSIONS

Delayed sleep phase appears to be common amongst Norwegian adolescents and is associated with negative outcomes such as lower average school grades, smoking, alcohol usage, and elevated anxiety and depression scores.

A comparison of actigraphy and polysomnography in older adults treated for chronic primary insomnia

STUDY OBJECTIVES

The present study explores the accuracy and clinical utility of actigraphy compared with polysomnography in older adults treated for chronic primary insomnia.

DESIGN

Polysomnographic and actigraphic data were collected before and after treatment.

SETTING

A university-based outpatient clinic for adults and elderly.

PARTICIPANTS

Thirty-four participants with chronic primary insomnia. Mean age was 60.5 years.

INTERVENTIONS

Participants received either a manualized treatment package based on cognitive-behavior therapy and sleep management or hypnotic-drug treatment (7.5 mg zopiclone) for 6 weeks (these findings are reported elsewhere).

MEASUREMENTS AND RESULTS

Although the sensitivity of actigraphy to detect sleep was very high (95.2%), actigraphy performed poorly in detecting wakefulness (specificity: 36.3%), yielding on an overall level of accuracy of 83.1%. However, the level of actigraphy accuracy was dependent upon polysomnography-registered sleep efficiency. Actigraphy underestimated total wake time and sleep-onset latency and consequently overestimated total sleep time and sleep efficiency. Compared with polysomnography, actigraphy captured only part of the treatment effects on total wake time and sleep-onset latency and failed to detect significant changes in sleep efficiency.

CONCLUSIONS

The present findings suggest that the clinical utility of actigraphy is still suboptimal in older adults treated for chronic primary insomnia and should, hence, be used in this clinical setting with the concurrent use of supplementary assessment methods.

Prevalence, severity and risk factors of restless legs syndrome in the general adult population in two Scandinavian countries

BACKGROUND AND PURPOSE

To estimate prevalence and severity (using the International Restless Legs Syndrome Study Group Rating Scale (IRLS)) and to identify risk factors of restless legs syndrome (RLS).

PATIENTS AND METHODS

Population-based cross-sectional study; 2005 randomly selected adults 18 years and above participated in a telephone interview in Norway and Denmark, employing the next-birthday technique.

RESULTS

Of the cross-section, 11.5% fulfilled the diagnostic criteria for RLS. Half of these reported the symptoms as moderate to very severe. Mean duration of the complaint was 10 years. Prevalence was higher in females than in males (13.4 vs 9.4%) and lowest in the youngest age group (18-29 years, 6.3%). From 30 years and above, no clear age-related difference was seen. Main predictors of RLS were insomnia (odds ratios: 1.71-3.16) and symptoms of periodic limb movements in sleep (3.20-7.85). The response rate was 47%, making the results less reliable.

CONCLUSIONS

This study indicates that there is a high occurrence of RLS among adults. Main predictors are insomnia and periodic limb movements in sleep.

The long-term effect of insomnia on work disability: the HUNT-2 historical cohort study

Chronic insomnia is common in the general population. Its effect on functioning and disability is usually attributed to an underlying condition, so the diagnosis of insomnia does not qualify for award of a disability pension in the United States or Europe. The aim of this study was to investigate whether insomnia, defined according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, contributed to long-term work disability. Using a historical cohort design, the authors gathered baseline data from a population-based Norwegian health study of 37,308 working-age people not claiming a disability pension through 1995-1997. The outcome was subsequent award of a disability pension (18-48 months after the health screening) as registered by the National Insurance Administration. Insomnia was a strong predictor of subsequent permanent work disability (adjusted odds ratio=3.90, 95% confidence interval: 3.20, 4.76). Sociodemographic and shift-work characteristics had little confounding effect (adjusted odds ratio=3.69, 95% confidence interval: 3.00, 4.53), and this association remained significant after adjustment for psychiatric and physical morbidity and for health-related behaviors (adjusted odds ratio=1.75, 95% confidence interval: 1.40, 2.20). This study suggests that insomnia should receive increased attention as a robust predictor of subsequent work disability.

Associations between night work and anxiety, depression, insomnia, sleepiness and fatigue in a sample of Norwegian nurses

Background

Night work has been reported to be associated with various mental disorders and complaints. We investigated relationships between night work and anxiety, depression, insomnia, sleepiness and fatigue among Norwegian nurses.

Methods

The study design was cross-sectional, based on validated self-assessment questionnaires. A total of 5400 nurses were invited to participate in a health survey through the Norwegian Nurses' Organization, whereof 2059 agreed to participate (response rate 38.1%). Nurses completed a questionnaire containing items on demographic variables (gender, age, years of experience as a nurse, marital status and children living at home), work schedule, anxiety/depression (Hospital Anxiety and Depression Scale), insomnia (Bergen Insomnia Scale), sleepiness (Epworth Sleepiness Scale) and fatigue (Fatigue Questionnaire). They were also asked to report number of night shifts in the last 12 months (NNL). First, the parameters were compared between nurses i) never working nights, ii) currently working nights, and iii) previously working nights, using binary logistic regression analyses. Subsequently, a cumulative approach was used investigating associations between NNL with the continuous scores on the same dependent variables in hierarchical multiple regression analyses.

Results

Nurses with current night work were more often categorized with insomnia (OR = 1.48, 95% CI = 1.10–1.99) and chronic fatigue (OR = 1.78, 95% CI = 1.02–3.11) than nurses with no night work experience. Previous night work experience was also associated with insomnia (OR = 1.45, 95% CI = 1.04–2.02). NNL was not associated with any parameters in the regression analyses.

Conclusion

Nurses with current or previous night work reported more insomnia than nurses without any night work experience, and current night work was also associated with chronic fatigue. Anxiety, depression and sleepiness were not associated with night work, and no cumulative effect of night shifts during the last 12 months was found on any parameters.

A practical approach to circadian rhythm sleep disorders

Circadian rhythm sleep disorders are common in clinical practice. The disorders covered in this review are delayed sleep phase disorder, advanced sleep phase disorder, free-running, irregular sleep-wake rhythm, jet lag disorder and shift work disorder. Bright light treatment and exogenous melatonin administration are considered to be the treatments of choice for these circadian rhythm sleep disorders. Circadian phase needs to be estimated in order to time the treatments appropriately. Inappropriately timed bright light and melatonin will likely worsen the condition. Measurements of core body temperature or endogenous melatonin rhythms will objectively assess circadian phase; however, such measurements are seldom or never used in a busy clinical practice. This review will focus on how to estimate circadian phase based on a careful patient history. Based on such estimations of circadian phase, we will recommend appropriate timing of bright light and/or melatonin in the different circadian rhythm sleep disorders. We hope this practical approach and simple recommendations will stimulate clinicians to treat patients with circadian rhythm sleep disorders.

Chronic mild stress affects sucrose intake and sleep in rats

Depression in humans is associated with sleep abnormalities of three types: altered rapid eye movement (REM) sleep, fragmented sleep, and reduced delta sleep. In an animal model of depression, chronic exposure to mild stressors (CMS, e.g. periods of soiled cage, reversed light/dark cycle, grouped housing, food and/or water deprivation) causes behavioral and hormonal changes which, in humans, often are associated with depression. In the CMS model, a reduced sucrose intake has been defined as one of the core symptoms of depression, anhedonia, although this finding is not consistent among various laboratories. In the present study, we investigated if the CMS procedure, in our laboratory, would cause decreased sucrose intake and, also, give sleep changes similar to what is found in depressed patients. Exposure to CMS decreased sucrose intake in our rats. The largest effect was obtained after 2 weeks of the stress protocol. CMS rats spent more time in REM sleep and showed more fragmented sleep compared to their baseline recording, while there were no changes in the control rats. Increased sleep fragmentation in CMS rats was particularly evident by increased number of arousals, and increased REM sleep and slow-wave-sleep-1 (SWS-1) episodes. The duration of sleep stage episodes was decreased. The amount of slow-wave-sleep-2 (SWS-2) was not decreased, however SWS-2 in percent of total SWS was reduced. Correlation analysis showed that animals that had less consumption of sucrose spent more time in REM sleep and had increased number of REM sleep episodes. In this study, CMS appears to be a model of depression.

Prevalence and Risk Factors of Subjective Sleepiness in the General Adult Population

STUDY OBJECTIVES

The aim of this study was to investigate the prevalence and risk factors of self-reported excessive daytime sleepiness (EDS) in Norway.

DESIGN

The Epworth Sleepiness Scale was administered by a telephone interview to a random sample of 2301 adult inhabitants of Norway. Questions of demography, symptoms of sleep disorders, and depression were included.

SETTING

Norway.

PARTICIPANTS

Two thousand three hundred one subjects, 18 years and older.

INTERVENTIONS

N/A.

MEASUREMENTS AND RESULTS

The mean score of the Epworth Sleepiness Scale was 6.95 (SD = 3.8), and 17.7% had a score (> 10), indicating EDS. Univariate logistic regression analyses showed that being a man; living in southern Norway; working nights; being young; having symptoms of cataplexy, restless legs, or periodic limb movement in sleep; having breathing pauses in sleep; and having symptoms of depression were significantly related to EDS. Of these 9 predictors, only symptoms of restless legs did not maintain the significant relationship with EDS when a multiple logistic regression analysis was performed.

CONCLUSIONS

The prevalence of EDS was high in this adult Norwegian population sample. EDS seems to be related to several symptoms of sleep disorders.

Insomnia and depressive symptoms in late pregnancy: a population-based study

A population-based questionnaire study of 2,816 women was conducted in week 32 of pregnancy to estimate the prevalence of and risk factors for insomnia and depressive symptoms. The Bergen Insomnia Scale (BIS) measured insomnia. The Edinburgh Postnatal Depression Scale (EPDS) measured depressive symptoms. The prevalence of insomnia (DSM-IV-TR criteria) was 61.9%, and mean BIS score 17.5 (SD = 10.5), significantly higher than among the general population. The prevalence of depressive symptoms (EPDS ≥ 10) was 14.6%. Depressive symptoms were strongly associated with insomnia during late pregnancy, especially with sleep durations <5 or >10 hours, sleep efficiency <75%, daytime impairment, and long sleep onset latency. Pelvic girdle pain and lower back pain was associated with insomnia, but not with depressive symptoms.

Shift work disorder among oil rig workers in the North Sea

STUDY OBJECTIVES

Shift work disorder (SWD) is a circadian rhythm sleep disorder caused by work hours during the usual sleep period. The main symptoms are excessive sleepiness and insomnia temporally associated with the working schedule. The aim of the present study was to examine SWD among shift workers in the North Sea.

DESIGN AND PARTICIPANTS

A total of 103 shift workers (2 weeks on 7 nights/7days, 12-h shifts, 4 weeks off), mean age 39.8 years, working at an oil rig in the North Sea responded to a questionnaire about SWD. They also completed the Pittsburgh Sleep Quality Index, Bergen Insomnia Scale, Epworth Sleepiness Scale, Composite Morningness Questionnaire, Subjective Health Complaint Inventory, Demand/Control, and Instrumental Mastery Oriented Coping (based on the Utrecht Coping list). Most of these instruments were administered during the first day of the 2-week working period, thus reflecting symptoms and complaints during the 4-week non-work period. The shift workers were also compared to day workers at the oil rig.

RESULTS

Twenty-four individuals were classified as suffering from SWD, yielding a prevalence for SWD of 23.3%. During the 4-week non-work period, individuals with SWD reported significantly poorer sleep quality, as measured by the Pittsburgh Sleep Quality Index, and more subjective health complaints than individuals not having SWD. There were no differences between the 2 groups in sleepiness, insomnia, circadian preference, psychological demands, or control. Individuals with SWD reported significantly lower scores on coping. The reports of shift workers without SWD were similar to those of day workers regarding sleep, sleepiness, subjective health complaints, and coping.

CONCLUSIONS

The prevalence of SWD was relatively high among these shift workers. Individuals with SWD reported poorer sleep quality and more subjective health complaints in the non-work period than shift workers not having SWD.