Børge Sivertsen

The epidemiology of insomnia: associations with physical and mental health. The HUNT-2 study.

OBJECTIVE The aim of the present study was to examine the association of insomnia symptoms with demographic and physical and mental conditions in a large population-based study. METHODS Cross-sectional data on insomnia and comorbid conditions were gathered from 47,700 individuals aged 20-89 in Norway. Comorbid conditions included anxiety and depression and the following physical conditions: asthma, allergy, cancer, hypertension, diabetes, migraine, headache, osteoporosis, fibromyalgia rheumatoid arthritis, arthrosis, Bechterews disease, musculoskeletal disorders, and obesity (body mass index >30). RESULTS Insomnia symptoms were found in 13.5% of the population and were more prevalent among women, older adults, and in individuals with less education. Reporting insomnia symptoms significantly increased the associations with a range of conditions, especially mental conditions, pain conditions with uncertain etiology and, to a lesser extent, chronic pain conditions. These findings remained significant also when adjusting for a range of potential confounders, whereas the association between insomnia and somatic conditions was largely reduced to a nonsignificant level in the fully adjusted analyses. CONCLUSION This study demonstrates that insomnia symptoms are associated with a range of different conditions. The findings suggest that the independent contribution of insomnia is strongest on conditions characterized by some level of psychological or psychosomatic properties.

Mindfulness-based stress reduction for patients with anxiety disorders: evaluation in a randomized controlled trial.

The aim of this study was to investigate the effect of mindfulness-based stress reduction (MBSR) for patients with heterogeneous anxiety disorders. Seventy-six self-referred patients were randomized to MBSR or a waiting-list control condition. Eight participants did not complete the eight-week MBSR intervention. Treatment completers improved significantly on all outcome measures compared to controls. The completer sample showed medium to large effect sizes on measures of anxiety (Cohens d = 0.55-0.97), and a large effect size for symptoms of depression (Cohens d = 0.97). Intention-to-treat analyses yielded effect sizes in the small to moderate range (Cohens d = 0.32-0.76). Gains were maintained at six months follow-up. The percentage of participants reaching recovered status was highest for symptom measures of depression and anxiety, and lower for worry and trait anxiety. Mediation analyses indicated that mindfulness fully mediated changes in acute anxiety symptoms, and partially mediated changes in worry and trait anxiety. However, the present study did not find evidence of temporal precedence for the proposed mediator. In the absence of true mediation and an active control condition, it cannot be ruled out that results are due to non-specific aspects of treatment. Despite these and other limitations, we conclude that MBSR is an effective treatment for anxiety disorders and related symptomatology.

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.

Sleep and use of electronic devices in adolescence: results from a large population-based study

Objectives Adolescents spend increasingly more time on electronic devices, and sleep deficiency rising in adolescents constitutes a major public health concern. The aim of the present study was to investigate daytime screen use and use of electronic devices before bedtime in relation to sleep. Design A large cross-sectional population-based survey study from 2012, the youth@hordaland study, in Hordaland County in Norway. Setting Cross-sectional general community-based study. Participants 9846 adolescents from three age cohorts aged 16–19. The main independent variables were type and frequency of electronic devices at bedtime and hours of screen-time during leisure time. Outcomes Sleep variables calculated based on self-report including bedtime, rise time, time in bed, sleep duration, sleep onset latency and wake after sleep onset. Results Adolescents spent a large amount of time during the day and at bedtime using electronic devices. Daytime and bedtime use of electronic devices were both related to sleep measures, with an increased risk of short sleep duration, long sleep onset latency and increased sleep deficiency. A dose–response relationship emerged between sleep duration and use of electronic devices, exemplified by the association between PC use and risk of less than 5 h of sleep (OR=2.70, 95% CI 2.14 to 3.39), and comparable lower odds for 7–8 h of sleep (OR=1.64, 95% CI 1.38 to 1.96). Conclusions Use of electronic devices is frequent in adolescence, during the day as well as at bedtime. The results demonstrate a negative relation between use of technology and sleep, suggesting that recommendations on healthy media use could include restrictions on electronic devices.

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.

Sleep patterns and insomnia among adolescents: a population-based study.

The aim of the current study was to examine sleep patterns and rates of insomnia in a population‐based study of adolescents aged 16–19 years. Gender differences in sleep patterns and insomnia, as well as a comparison of insomnia rates according to DSM‐IV, DSM‐V and quantitative criteria for insomnia (Behav. Res. Ther., 41, 2003, 427), were explored. We used a large population‐based study in Hordaland county in Norway, conducted in 2012. The sample included 10 220 adolescents aged 16–18 years (54% girls). Self‐reported sleep measurements included bedtime, rise time, time in bed, sleep duration, sleep efficiency, sleep onset latency, wake after sleep onset, rate and frequency and duration of difficulties initiating and maintaining sleep and rate and frequency of tiredness and sleepiness. The adolescents reported short sleep duration on weekdays (mean 6:25 hours), resulting in a sleep deficiency of about 2 h. A majority of the adolescents (65%) reported sleep onset latency exceeding 30 min. Girls reported longer sleep onset latency and a higher rate of insomnia than boys, while boys reported later bedtimes and a larger weekday–weekend discrepancy on several sleep parameters. Insomnia prevalence rates ranged from a total prevalence of 23.8 (DSM‐IV criteria), 18.5 (DSM‐V criteria) and 13.6% (quantitative criteria for insomnia). We conclude that short sleep duration, long sleep onset latency and insomnia were prevalent in adolescents. This warrants attention as a public health concern in this age group.

Insomnia as a risk factor for ill health: results from the large population-based prospective HUNT Study in Norway

Insomnia co‐occurs with many health problems, but less is known about the prospective associations. The aim of the current study was to investigate if insomnia predicts cumulative incidence of mental and physical conditions. Prospective population‐based data from the two last Nord‐Trøndelag Health Studies (HUNT2 in 1995–97 and HUNT3 in 2006–08), comprising 24 715 people in the working population, were used to study insomnia as a risk factor for incidence of physical and mental conditions. Insomnia was defined according to the 4th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM‐IV). Insomnia at HUNT2 was a significant risk factor for incidence of a range of both mental and physical conditions at HUNT3 11 years later. Most effects were only slightly attenuated when adjusting for confounding factors, and insomnia remained a significant risk factor for the following conditions in the adjusted analyses: depression [odds ratio (OR): 2.38, 95% confidence interval (CI): 1.91–2.98], anxiety (OR: 2.08, 95% CI: 1.63–2.64), fibromyalgia (OR: 2.05, 95% CI: 1.51–2.79), rheumatoid arthritis (OR: 1.87, 95% CI: 1.29–2.52), whiplash (OR: 1.71, 95% CI: 1.21–2.41), arthrosis (OR: 1.68, 95% CI: 1.43–1.98), osteoporosis (OR: 1.52, 95% CI: 1.14–2.01, headache (OR: 1.50, 95% CI: 1.16–1.95, asthma (OR: 1.47, 95% CI: 1.16–1.86 and myocardial infarction (OR: 1.46, 95% CI: 1.06–2.00). Insomnia was also associated significantly with incidence of angina, hypertension, obesity and stroke in the crude analyses, but not after adjusting for confounders. We conclude that insomnia predicts cumulative incidence of several physical and mental conditions. These results may have important clinical implications, and whether or not treatment of insomnia would have a preventive value for both physical and mental conditions should be studied further.

Does insomnia predict sick leave? The Hordaland Health Study.

OBJECTIVE The purpose of this study is to prospectively examine the independent contribution of symptoms of insomnia on sick leave. METHODS We used a historical cohort design with 4 years of follow-up. Information on sick leave was obtained from Norwegian official registry data and merged with health information from the Hordaland Health Study in Western Norway, 1997 to 1999. Six thousand eight hundred ninety-two participants aged 40 to 45 years were assessed for self-reported symptoms of insomnia, sociodemographic factors, lifestyle behaviors, body mass index, symptoms of sleep apnea, anxiety, depression, as well as a range of somatic diagnoses, somatic symptoms, and pain. The outcome was the total number of sick days during a 4-year follow-up period, as registered in the official registries by the National Insurance Administration. RESULTS Overall, insomnia was found to be a significant predictor of sick leave [odds ratio (OR)=2.20; 95% confidence interval (CI), 1.77-2.74], and the effect remained significant when adjusting for possible confounders (OR=1.51; 95% CI, 1.19-1.94). The effect increased with longer durations of sickness leave. CONCLUSION This is the first study to demonstrate that insomnia is an independent risk factor for long-term sick leave.

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.

Sleep problems in children with autism spectrum problems: a longitudinal population-based study:

This study examined the prevalence and chronicity of sleep problems in children who manifest problems believed to be typical of Autism Spectrum Disorders (ASD). Using data from a longitudinal total population study, symptoms of ASD, insomnia and potential explanatory factors were assessed at ages 7–9 and 11–13. Children were included in a group defined as having Autism Spectrum Problems (ASP) if they scored above a strict threshold on the Autism Spectrum Screening Questionnaire (ASSQ). Twenty-eight (0.8%) of 3700 children fulfilled the selected criteria for ASP at both waves, and the prevalence of chronic insomnia was more than ten times higher in these children compared to the controls. Children with ASP developed more sleep problems over time, with an incidence rate at wave 2 of 37.5% compared to 8.6% in the controls. The sleep problems were more persistent over time, with a remission rate of 8.3% compared to 52.4% in the controls. ASP was a strong predictor of sleep problems at wave 2 (OR = 12.44), and while emotional and behavioural problems explained a large proportion of this association, the effect of ASP on insomnia remained significant in the fully adjusted model (OR = 3.25). These findings call for increased awareness of sleep problems in children with ASP.