Study author Dr. Marcin Wojnar of the University of Michigan and the University of Warsaw in Poland said that identifying those at high risk of suicide is important in preventing it and these findings indicate that insomnia may be a modifiable risk factor for suicide in the general population.
"This has implications for public health as the presence of sleep problems should alert doctors to assess such patients for a heightened risk of suicide even if they don't have a psychiatric condition," Wojnar said in a statement.
The scientists examined the relationship over one year between three characteristics of insomnia -- difficulty falling asleep, difficulty staying asleep and waking at least two hours earlier than desired -- and three suicidal behaviors -- suicidal thoughts, planning and attempts -- of 5,692 Americans.
About 35 percent of those studied reported experiencing at least one type of sleep disturbance in the preceding 12 months.
The most consistent link was seen for early morning awakening, which was related to all suicidal behaviors. People with this problem were twice as likely as those with no sleep problems to have had suicidal thoughts in the preceding 12 months, 2.1 times more likely to have planned suicide and 2.7 times more likely to have tried to kill themselves.
The findings are being presented at the World Psychiatric Association international congress.