Seasonal Variations in Sleep Problems at Latitude 63 -65  in Norway: The Nord-Trondelag Health Study, 1995-1997

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

(2010) A. K. Knudsen et al.   AMERICAN JOURNAL OF EPIDEMIOLOGY

Underexposure to light at work and its association to insomnia and sleepiness

(2010) Damien Leger et al.   JOURNAL OF PSYCHOSOMATIC RESEARCH

Insomnia Symptoms and Use of Health Care Services and Medications: The HUNT-2 Study

(2009) Børge Sivertsen et al.   Behavioral Sleep Medicine

Accentuation of suicides but not homicides with rising latitudes of Greenland in the sunny months

(2009) Karin S Björkstén et al.   BMC Psychiatry

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

(2009) Arnstein Mykletun et al.   BRITISH JOURNAL OF PSYCHIATRY

The epidemiology of insomnia: Associations with physical and mental health.

(2009) Børge Sivertsen et al.   JOURNAL OF PSYCHOSOMATIC RESEARCH

Self-reported seasonality is associated with complaints of sleep problems and deficient sleep duration: the Hordaland Health Study

(2008) NICOLAS M. ØYANE et al.   JOURNAL OF SLEEP RESEARCH

Monthly variation in prevalence rates of comorbid depression and anxiety in the general population at 63–65° North: The HUNT study

(2007) Eystein Stordal et al.   JOURNAL OF AFFECTIVE DISORDERS