The links remained even when researchers adjusted their figures to account for the influence of mental illness and chronic health conditions.
Wojnar acknowledged that the study didn't take into account the timing of sleeplessness to determine whether it came before suicidal thoughts or attempts. The study also didnt look at people who committed suicide, nor did it prove a cause-and-effect relationship between suicide and insomnia.
Mental-health experts estimate that many more people -- perhaps 10 to 40 times more -- try to commit suicide than actually kill themselves. However, suicide is still a huge problem, taking an estimated 877,000 lives a year, according to the World Health Organization.
Research links anxiety to trouble falling asleep and difficulty sleeping through the night, while early awakening is connected to depression, said Alan Berman, executive director of the American Association of Suicidology.
"For people who are suffering from insomnia over some period of time, it affects all aspects of daily functioning -- the ability to think clearly, to focus and problem solve and synthesize information and make decisions," he said.
Also, insomnia "basically lowers the threshold for impulsive behavior and for being reactive to an emotional event."
What to do? Step in and try to resolve the problem, Berman said. "Effective intervention is really important," he said. "Insomnia is something we can observe. People know about it when they're experiencing it and can respond to it."
Learn more about suicide from the U.S. National Institutes of Health.
SOURCES: Marcin Wojnar, M.D., Ph.D., Medical University of Warsaw, Poland, and University of Michigan, Ann Arbor; Al
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