Arnstein Mykletun

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.

Age-specific prevalence of the metabolic syndrome defined by the International Diabetes Federation and the National Cholesterol Education Program: the Norwegian HUNT 2 study

BackgroundThe 2005 International Diabetes Federation (IDF) definition of the metabolic syndrome was designed to be useful worldwide, but to date few prevalence studies have used that definition in European populations. We estimated the age- and sex-stratified prevalence of IDF-defined metabolic syndrome in a county of Norway and compared it with the prevalence estimated using the revised National Cholesterol Education Program-Adult Treatment Panel-III definition (2005 ATP III).MethodsCross-sectional analysis of 10,206 participants aged 20–89 years in the Nord-Trøndelag Health Study 1995–97 (HUNT 2).ResultsPrevalence of IDF-defined metabolic syndrome was 29.6% (95% CI: 28.8 to 30.5), compared to 25.9% (95% CI: 25.0 to 26.7) using the 2005 ATP III criteria. The prevalence of IDF-defined metabolic syndrome increased from 11.0% in the 20–29 years age group to 47.2% in the 80–89 years group in men, and from 9.2% to 64.4% for women in the corresponding age groups. Among men and women aged ≥60 years, the IDF criteria classified 56.7% and 75.0%, respectively, as having central obesity, and 89.3% and 90.9%, respectively, as being hypertensive.ConclusionAccording to both definitions, the prevalence of the metabolic syndrome increased strongly with age. The IDF and the American Heart Association/National Heart, Lung, and Blood Institute guidelines for clinical management of metabolic syndrome would classify a high proportion of elderly Norwegians as in need of overall risk assessment for cardiovascular disease.

Anxiety, depression, and cause-specific mortality: the HUNT study.

Objective: To investigate empirically the association between anxiety/depression and cause-specific mortality with particular attention to the underlying mechanisms and causes of death. Depression reportedly increases general mortality. For cause-specific mortality, there is evidence depression has an effect on cardiovascular disease (CVD) mortality and suicide. Less information is known as to other mortality diagnoses. There is scarce and conflicting literature on anxiety in relation to mortality. Methods: Employing a historical cohort design, we used a link between an epidemiological cohort study and a comprehensive national mortality database. We gathered baseline information on physical and mental health (Hospital Anxiety and Depression Scale, HADS) from the population-based health study (n = 61,349). Causes of death were registered with International Classification of Diagnoses, 10th edition (ICD-10) during mean follow-up of 4.4 years. Results: Case-level depression increased the mortality rate for all major disease-related causes of death, whereas case-level anxiety and comorbid anxiety/depression did not. The effect of depression was similar for cardiac mortality compared with all other causes combined, and confounding effects were also very similar. Symptom load of anxiety was associated negatively with both CVD and other cause mortality in fully adjusted models. Accidents and suicide were associated primarily with comorbid anxiety/depression. Conclusions: Depression is a risk factor for all major disease-related causes of death; it is not limited to CVD mortality or suicide. Because the association between depression and cardiac mortality was comparable to the other causes of death combined and confounding and mediating factors were markedly similar, future investigation as to the mechanisms underlying the effect of depression on mortality should not be limited to CVD mortality. BMI = body mass index; CAGE = screening instrument for alcohol problems; CVD = cardiovascular disease; HADS = Hospital Anxiety and Depression Scale (A or D for subscales); ICD-8/9/10 = International Classification of Diagnoses, 8th/9th/10th edition; OR = odds ratio; HUNT = Health Study of Nord-Trøndelag County, Norway.

The Association Between Anxiety, Depression, and Somatic Symptoms in a Large Population: The HUNT-II Study

Objective: Somatic symptoms are prevalent in the community, but at least one third of the symptoms lack organic explanation. Patients with such symptoms have a tendency to overuse the health care system with frequent consultations and have a high degree of disability and sickness compensation. Studies from clinical samples have shown that anxiety and depression are prevalent in such functional conditions. The aim of this study is to examine the connection between anxiety, depression, and functional somatic symptoms in a large community sample. Method: The HUNT-II study invited all inhabitants aged 20 years and above in Nord-Trøndelag County of Norway to have their health examined and sent a questionnaire asking about physical symptoms, demographic factors, lifestyle, and somatic diseases. Anxiety and depression were recorded by the Hospital Anxiety and Depression Scale. Of those invited, 62,651 participants (71.3%) filled in the questionnaire. A total of 10,492 people were excluded due to organic diseases, and 50,377 were taken into the analyses. Results: Women reported more somatic symptoms than men (mean number of symptoms women/men: 3.8/2.9). There was a strong association between anxiety, depression, and functional somatic symptoms. The association was equally strong for anxiety and depression, and a somewhat stronger association was observed for comorbid anxiety and depression. The association of anxiety, depression, and functional somatic symptoms was equally strong in men and women (mean number of somatic symptoms men/women in anxiety: 4.5/5.9, in depression: 4.6/5.9, in comorbid anxiety and depression: 6.1/7.6, and in no anxiety or depression: 2.6/3.6) and in all age groups. The association between number of somatic symptoms and the total score on Hospital Anxiety and Depression Scale was linear. Conclusion: There was a statistically significant relationship between anxiety, depression, and functional somatic symptoms, independent of age and gender. ME = myalgic encephalomyelitis; FSS = functional somatic symptoms; ECA = Epidemiological Catchment Area Study; HADS = Hospital Anxiety and Depression Scale; HADS-A = anxiety subscale of Hospital Anxiety and Depression Scale; HADS-D = depression subscale of Hospital Anxiety and Depression Scale; HADS-AD = comorbid anxiety and depression on Hospital Anxiety and Depression Scale; HADS-T = total score on Hospital Anxiety and Depression Scale; OR = odds ratio.

Depression in relation to age and gender in the general population: the Nord-Trøndelag Health Study (HUNT)

Objective: Previous sample studies of depression have shown a higher prevalence of depression in women, and an inconsistent relation to age has been found for both genders. The aim of the present study was to investigate depression in relation to gender and age in the general adult population.

Does a higher educational level protect against anxiety and depression? The HUNT study

The relationship of education to the experience of anxiety and depression throughout adult life is unclear. Our knowledge of this relationship is limited and inconclusive. The aim of this study was to examine (1) whether higher educational level protects against anxiety and/or depression, (2) whether this protection accumulates or attenuates with age or time, and (3) whether such a relationship appears to be mediated by other variables. In a sample from the Nord-Trøndelag Health Study 1995--1997 (HUNT 2) (N=50,918) of adults, the cross-sectional associations between educational level and symptom levels of anxiety and depression were examined, stratified by age. The long-term effects of educational level on anxiety/depression were studied in a cohort followed up from HUNT 1 (1984--1986) to HUNT 2 (N=33,774). Low educational levels were significantly associated with both anxiety and depression. The coefficients decreased with increasing age, except for the age group 65-74 years. In the longitudinal analysis, however, the protective effect of education accumulated somewhat with time. The discrepancy between these two analyses may be due to a cohort effect in the cross-sectional analysis. Among the mediators, somatic health exerted the strongest influence, followed by health behaviors and socio-demographic factors. Higher educational level seems to have a protective effect against anxiety and depression, which accumulates throughout life.

The Health Status of Nonparticipants in a Population-based Health Study The Hordaland Health Study

The authors aimed to examine whether nonparticipation in a population-based health study was associated with poorer health status; to determine whether specific health problems were overrepresented among nonparticipants; and to explore potential consequences of participation bias on associations between exposures and outcomes. They used data from the Hordaland Health Study (HUSK), conducted in western Norway in 1997-1999. Of 29,400 persons invited, 63.1% participated in the study. Information from HUSK was linked with the Norwegian national registry of disability pensions (DPs), including information about DP diagnosis. The risk of DP receipt was almost twice as high among nonparticipants as participants (relative risk = 1.88, 95% confidence interval: 1.81, 1.95). The association was strongest for DPs received for mental disorders, with a 3-fold increased risk for nonparticipation. Substance abuse, psychotic disorders, and personality disorders were especially overrepresented among nonparticipants. The authors simulated the impact of nonparticipation on associations between exposures and outcomes by excluding HUSK participants with higher symptoms of common mental disorders (exposure) and examining the impact on DP (outcome). This selective exclusion modestly reduced associations between common mental disorders and DP. The authors conclude that nonparticipants have poorer health, but this is disorder-dependent. Participation bias is probably a greater threat to the validity of prevalence studies than to studies of associations between exposures and outcomes.

Levels of anxiety and depression as predictors of mortality: the HUNT study

BACKGROUND Depression is reported to be associated with increased mortality, although underlying mechanisms are uncertain. Associations between anxiety and mortality are also uncertain. AIMS To investigate associations between individual and combined anxiety/depression symptom loads (using the Hospital Anxiety and Depression Scale (HADS)) and mortality over a 3-6 year period. METHOD We utilised a unique link between a large population survey (HUNT-2, n = 61 349) and a comprehensive mortality database. RESULTS Case-level depression was associated with increased mortality (hazard ratio (HR) = 1.52, 95% CI 1.35-1.72) comparable with that of smoking (HR = 1.59, 95% CI 1.44-1.75), and which was only partly explained by somatic symptoms/conditions. Anxiety comorbid with depression lowered mortality compared with depression alone (anxiety depression interaction P = 0.017). The association between anxiety symptom load and mortality was U-shaped. CONCLUSIONS Depression as a risk factor for mortality was comparable in strength to smoking. Comorbid anxiety reduced mortality compared with depression alone. The relationship between anxiety symptoms and mortality was more complex with a U-shape and highest mortality in those with the lowest anxiety symptom loads.

Prevalence, classification, and severity of Epilepsy in children in western Norway

Summary: Purpose: To determine prevalence of active epilepsy in school children in a defined area and assess the usefulness of International League Against Epilepsy classification of seizures and epileptic syndromes, with special emphasis on frequency, additional handicaps, and therapeutic problems of severe cases.

Help‐seeking behaviour in patients with anxiety disorder and depression

Objective:  The objective of this study was to investigate help‐seeking behaviour among persons with anxiety disorder and depression based on self‐rating in a Norwegian population (the HUNT study).