Teenagers who thought about or attempted suicide were more likely to have suffered sleep disorders in earlier years, researchers say.
Idaho State University psychology professor Maria Wong, who worked on the study, said the finding should aid parents, educators and others in identifying teens at risk of harming themselves.
She said adolescents are more willing to talk about sleep problems than suicidal thoughts or attempts, giving adults an opening to discuss and monitor problems that may be more serious than simply a teen's trouble falling asleep.
"It's easier to broach the topic of sleep with patients, since it's easier to talk about a physical problem," said Wong, who worked with colleagues from the University of Michigan on the study, published in the Journal of Psychiatric Research.
"It's easier for them to answer questions like, 'Did you sleep well last night?' and get into why they are not sleeping well and how they are feeling lately," Wong said.
The study tracked 280 boys and 112 girls from Michigan, beginning when they were ages 12 to 14 and ending when they were between 15 and 17.
Participants responded to such questions as whether they had nightmares, felt tired or otherwise had trouble sleeping. They also were asked about whether they had cut or otherwise hurt themselves.
Not all the adolescents with abnormal sleep had suicidal thoughts, but those aged 15 to 17 who had suicidal thoughts were more likely to have had sleep problems in earlier years.
Sixty percent of teens ages 15 to 17 who engaged in suicidal behavior had trouble sleeping at 12 to 14. Among those who only thought about suicide, 47 percent had trouble sleeping in earlier years.
By comparison, only 26 percent of teens with no suicidal thoughts or behavior had trouble sleeping at ages 12 to 14.
Wong said the design of the research screened for factors such as depression, unlike past research in this area. It also adjusted for alcoholism and suicidal tendencies by parents.
Results from the study are consistent with previous findings in adults by researchers who found strong links between sleep problems and suicide.
Wong stressed that scientists did not prove that sleep problems caused suicidal tendencies among adolescents, only that the two things tend to occur together.
The experiment also did not demonstrate that suicidal thoughts or behavior cause sleep disorders.
She said she hopes to conduct further research to explain why there is a relationship between sleep problems and suicide in adolescence.