Inger Hilde Nordhus

A new scale for measuring insomnia: the Bergen Insomnia Scale.

A new scale for the measurement of insomnia, the Bergen Insomnia Scale, was constructed on the basis of current formal and clinical diagnostic criteria for insomnia. There are six items, of which the first three pertain to sleep onset, maintenance, and early morning wakening insomnia, respectively. The last three items refer to not feeling adequately rested, experiencing daytime impairment, and being dissatisfied with current sleep. This scale was validated in three samples, 320 students, 2,645 community persons, and 225 patients. Cronbach alphas in the three samples were .79, .87, and .80, respectively. The 2-wk. test-retest reliability for students was .77. In the student and the patient samples, a two-factor solution was found, nocturnal symptoms and daytime symptoms, but in the community sample, a one-factor solution was found. The Bergen Insomnia Scale discriminated well between the patient sample and the other two. In all three, values of convergent and discriminative validity in relation to other self-report measures were good, as well as in relation to polysomnographic data for patients. It is concluded that the Bergen Insomnia Scale has good psychometric properties. It is one of very few insomnia scales which provide normative data for comparisons and which has been validated against subjective as well as polysomnographic data.

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.

The bidirectional association between depression and insomnia: the HUNT study.

Objective Depression and insomnia are closely linked, yet our understanding of their prospective relationships remains limited. The aim of the current study was to investigate the directionality of association between depression and insomnia. Methods Data were collected from a prospective population-based study comprising the most recent waves of the Nord-Trøndelag Health Study (HUNT) (the HUNT2 in 1995–1997 and the HUNT3 in 2006–2008). A total of 24,715 persons provided valid responses on the relevant questionnaires from both surveys. Study outcomes were onset of depression or insomnia at HUNT3 in persons not reporting the other disorder in HUNT2. Results Both insomnia and depression significantly predicted the onset of the other disorder. Participants who did not have depression in HUNT2 but who had insomnia in both HUNT2 and HUNT3 had an odds ratio (OR) of 6.2 of developing depression at HUNT3. Participants who did not have insomnia in HUNT2 but who had depression in both HUNT2 and HUNT3 had an OR of 6.7 of developing insomnia at HUNT3. ORs were only slightly attenuated when adjusting for potential confounding factors. Conclusions The results support a bidirectional relationship between insomnia and depression. This finding stands in contrast to the previous studies, which have mainly focused on insomnia as a risk factor for the onset of depression.

A randomized controlled trial of cognitive behavioral therapy for anxiety and depression in COPD

BACKGROUND Previous research indicates a high prevalence of untreated anxiety and depression in patients with chronic obstructive pulmonary disease (COPD). The current study examined the effect of cognitive behavioral therapy (CBT) in groups for co-morbid, clinically significant anxiety and depression in COPD outpatients of both sexes. METHODS In a randomized, controlled trial, CBT (n = 25) was compared with enhanced standard care (n = 26). Participants in both conditions were followed up at 2 and 8 months from baseline. Main outcome measures comprised the Beck Anxiety Inventory and the Beck Depression Inventory-II. Measures of health status and sleep were included as secondary outcomes. The effects of sex and age were also investigated. RESULTS CBT resulted in improvement in symptoms of anxiety and depression, with effect sizes of 1.1 and 0.9 at post-treatment, respectively. The improvement was maintained at the 8-month follow-up, with effect sizes of 1.4 and 0.9. In the control group, there was no significant change. Compared to men, women had higher symptom levels throughout the whole study period. Younger patients had more anxiety and depression, age had also differential effects in the two groups on change in depressive symptoms. Changes in sleep and health status were small in both groups. CONCLUSIONS The findings indicate that CBT may provide rapid symptom relief for COPD patients with clinically significant anxiety and depression, and underline the need for integrating mental health care into the overall medical regimen for COPD.

A Norwegian population‐based study on the risk and prevalence of obstructive sleep apnea The Akershus Sleep Apnea Project (ASAP)

The Berlin Questionnaire (BQ) is a widely used screening tool for obstructive sleep apnea (OSA), but its performance in the general population setting is unknown. The prevalence of OSA in middle‐aged adults is not known in Norway. Accordingly, the aims of the current study were to evaluate the utility of the BQ for OSA screening in the general population and to estimate the prevalence of OSA in Norway. The study population consisted of 29 258 subjects (aged 30–65 years, 50% female) who received the BQ by mail. Of these, 16 302 (55.7%) responded. Five‐hundred and eighteen subjects were included in the clinical sample and underwent in‐hospital polysomnography. Screening properties and prevalence were estimated by a statistical model that adjusted for bias in the sampling procedure. Among the 16 302 respondents, 24.3% (95% confidence interval (CI) = 23.6–25.0%) were classified by the BQ to be at high‐risk of having OSA. Defining OSA as an apnea–hypopnea index (AHI) ≥5, the positive predictive value of the BQ was estimated to be 61.3%, the negative predictive value 66.2%, the sensitivity 37.2% and the specificity 84.0%. Estimated prevalences of OSA were 16% for AHI ≥ 5 and 8% for AHI ≥ 15. In conclusion, the BQ classified one out of four middle‐aged Norwegians to be at high‐risk of having OSA, but the screening properties of the BQ were suboptimal. The estimated prevalence of OSA was comparable to previous estimates from general populations in the USA, Australia and Europe.

Insomnia and long sleep duration are risk factors for later work disability. The Hordaland Health Study

Both insomnia and sleep duration have previously been linked with a range of adverse outcomes, but no studies have explored their relative effect on subsequent work disability. The aim of the present study was to investigate the contribution of insomnia versus sleep duration to later long‐term work disability. Using a historical cohort design with 4‐year follow‐up, data on insomnia, sleep duration and potential confounders were gathered from 6599 working persons (40–45 years). The outcome was award of disability pension, as registered in the National Insurance Administration. After controlling for baseline exposure to disability and sick leave, insomnia was a strong predictor of permanent work disability [odds ratio (OR) = 4.56], and this effect remained significant after controlling for sleep duration, as well as for other possible confounders (OR = 1.88). Short sleep duration was not significantly associated with subsequent work disability, while long sleep duration (>8.5 h) did predict work disability (OR = 2.96), also in the fully adjusted model (OR = 2.14).The present study demonstrates that both insomnia and long sleep duration are strong and independent risk factors for subsequent work disability.

Psychological treatment of late-life anxiety: An empirical review.

This study provides a meta-analytic review of nonpharmacological interventions for late-life anxiety, focusing on treatment efficacy. Included in the analysis are studies in which a comparison was made either to a control condition or to another treatment. A total of 15 outcome studies, published or reported between January 1975 and January 2002, were identified involving 495 participants (mean age exceeding 55.0 years and a grand mean of 69.5 years) and providing 20 separate treatment interventions. The analysis indicated that psychological interventions were reliably more effective than no treatment on self-rated and clinician-rated measures of anxiety, yielding an effect size of .55. Maintenance of treatment gains (a minimum of 6 months follow-up) was insufficiently reported across studies to allow for a reliable demonstration of an overall estimate of long-term efficacy. It is concluded that psychological interventions produce significant improvements, but the analyses must be qualified by data limitations in the research synthesis.

Exercise as a treatment for depression: A meta-analysis

BACKGROUND This meta-analysis of randomized controlled trials (RCTs) examines the efficacy of physical exercise as treatment for unipolar depression, both as an independent intervention and as an adjunct intervention to antidepressant medication. METHODS We searched PsycINFO, EMBASE, MEDLINE, CENTRAL, and Sports Discus for articles published until November 2014. Effect sizes were computed with random effects models. The main outcome was reduction in depressive symptoms or remission. RESULTS A total of 23 RCTs and 977 participants were included. Physical exercise had a moderate to large significant effect on depression compared to control conditions (g=-0.68), but the effect was small and not significant at follow-up (g=-0.22). Exercise compared to no intervention yielded a large and significant effect size (g=-1.24), and exercise had a moderate and significant effect compared to usual care (g=-0.48). The effects of exercise when compared to psychological treatments or antidepressant medication were small and not significant (g=-0.22 and g=-0.08, respectively). Exercise as an adjunct to antidepressant medication yielded a moderate effect (g=-0.50) that trended toward significance. LIMITATIONS Use of the arms with the largest clinical effect instead of largest dose may have overestimated the effect of exercise. CONCLUSIONS Physical exercise is an effective intervention for depression. It also could be a viable adjunct treatment in combination with antidepressants.

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.

Behavioral treatment of insomnia in older adults: an open clinical trial comparing two interventions.

Fifty-five insomniacs, 60 years or above, participated in a behavioral treatment program, comparing two interventions (sleep hygiene+stimulus control vs sleep hygiene+relaxation tape). Half of the subjects were randomized to a waiting-list condition prior to treatment. No significant changes were observed during the waiting-list period. During the treatment period however, the subjects improved on several sleep parameters, and treatment gains were maintained at a 6-month follow-up. The effects of treatment were greater for nocturnal measures (e.g. sleep onset latency and total sleep time) as compared to daytime measures (e.g. life satisfaction, daytime alertness) and not-targeted behavior (medication use). There were no differences in treatment effects for the two interventions.