Objective:
The aim of this study was to examine how neuroticism, stressful life events, self-
rated health, life satisfaction, and selected lifestyle factors were related to insomnia both by sex
and among users and nonusers of prescribed sleep medication (PSM).
Design:
Cross-sectional data from the Norwegian Nord-Trøndelag Health Study (HUNT3,
2006–2008), a population-based health survey, were linked to individual data from the Norwe-
gian Prescription Database.
Methods:
Logistic regression analyses were used to investigate the associations between the
selected variables and insomnia in both males and females and among subjects using and not
using PSM. Individuals were considered to have a presumptive diagnosis of insomnia disorder
if they reported difficulty with sleep initiation, sleep maintenance, or early morning awakening
several days per week for the last 3 months. PSMs were categorized as anxiolytics or hypnotics;
the dose was estimated according to defined daily dose (DDD).
Results:
Of the total 50,805 participants, 6,701 (13.2%) used PSM. The proportions of PSM
users were larger among elderly participants. Increased risk of insomnia was strongly associated
with poor self-rated health and higher level of neuroticism. These associations were evident for
both sexes and were similar among both users and nonusers of PSM. Low satisfaction with life
was strongly related to insomnia, but only among nonusers of PSM. Increased doses of PSM
were not associated with reduced likelihood of insomnia.
Conclusion:
Insomnia is a problem among both users and nonusers of PSM and is associated
with psychosocial factors. Our findings suggest that successful treatment for sleep problems
should take individual variation into account, such as age, sex, personality traits, satisfaction
with life, and health perception.