APSS: Risks of Insomnia Persist, Even Among People Who Sleep Well

MINNEAPOLIS, June 15 -- Even among self-reported "good sleepers," there's a risk of a bout of insomnia, researchers said here.
For example, scientists determined that if you have a family member who was diagnosed with insomnia then you have three times the risk of having an episode yourself within a year when compared with someone who doesn't have an insomniac in the family tree, Melanie LeBlanc, Ph.D., of Universite Laval, Quebec City, Quebec told attendees at the Associated Professional Sleep Societies meeting.
Because there was little data on the incidence and risk factors for insomnia, Dr. LeBlanc and colleagues recruited 464 participants who described themselves as "good sleepers".
They were evaluated through mailed questionnaires three times: At the start of the study, at six months, and after a year. The results were based on the responses of the 437 participants who turned in at least two reports.
"The most predisposing risk factor was having a previous bout of insomnia," Dr. LeBlanc said. The risk of a second insomnia problem was 5.42 times that of persons who had never had insomnia.
Lesser risk factors, but still significant, were a person's predisposition to arousability - that is, they were light sleepers who awoke to noises that ordinarily would not trouble others - with an odds ratio for an episode of insomnia of 1.12. People with general health problems had an odds ratio of 1.03; those with bodily pain had an odds ratio of 1.02.
"Because we had a large number of people in our study, even these small increases were statistically significant," Dr. LeBlanc said. "All the risks reached a P=<0.01 value."
The participants were assessed through use of the Insomnia Severity Index, the Pittsburgh Sleep Quality Index, the Beck Depression Inventory, the State-Trait Anxiety Inventory, the Arousal Predisposition Scale, the NEO Five-Factors Inventory, the Life Experience Survey, the Perceived Stress Scale, the Coping inventory for Stressful Situations, and the SF-12v2 Health Survey (SF-12).
The researchers also found that when a person in the study suffered through a bout of insomnia, it significantly increased a person's depressive symptoms and their anxiety symptoms and decreased their overall subjective mental health examination.
They noted that incident insomnia cases - problems with sleeping that occurred to these "good sleepers" -- were associated with life events.
"Improved knowledge of these risk factors could guide the development of more effective public health prevention and intervention programs for insomnia," said LeBlanc in her poster presentation.

Primary source: SleepSource reference: Melanie LeBlanc, "INCIDENCE AND RISK FACTORS OF INSOMNIA IN A POPULATION-BASED SAMPLE" Sleep,Vol. 30, Abstract Supplement, 2007, A261.