Adolescents who go to bed earlier are significantly less likely to suffer from depression and to think about committing suicide, a new study shows.
The result suggests that earlier bedtimes could have a protective effect by lengthening sleep duration and increasing the likelihood of
getting enough sleep, said researchers at Columbia University Medical Center.
Adolescents with parental set bedtimes of midnight or later were 24 percent more likely to suffer from depression and 20 percent more likely to have suicidal ideation than adolescents with parental set bedtimes of 10 p.m. or earlier, according to the study published in the Jan. issue of Sleep.
Adolescents who reported that they usually sleep for five or fewer hours per night were 71 percent more likely to suffer from depression and 48 percent more likely to think about committing suicide than those who reported getting eight hours of nightly sleep.
Participants who reported that they "usually get enough sleep" were significantly less likely to suffer from depression and suicidal ideation,
said the study.
The results strengthen the argument that short sleep duration could play a role in the etiology of depression, said lead author James E.
Gangwisch, PhD, assistant professor at the center.
"Our results are consistent with the theory that inadequate sleep is a risk factor for depression, working with other risk and protective factors through multiple possible causal pathways to the development of this mood
disorder," said Gangwisch. "Adequate quality sleep could therefore be a preventative measure against depression and a treatment for depression."
The researchers collected from 15,659 adolescents and their parents who had participated in the National Longitudinal Study of Adolescent Health (Add Health), a school-based, nationally representative, probability-based sample of U.S. students in grades seven to 12 in 1994 to 1996.
Seven percent of participants (1,050) were found to have depression using the Centers for Epidemiologic Study-Depression Scale, and 13 percent (2,038) reported that they seriously thought about committing suicide during the past 12 months.
Depression and suicidal ideation were associated with later parental set bedtime, shorter sleep duration, self-perception of not getting enough sleep, female sex, older age and lower self- perception of how much parents care, the study concluded.