填空题 It seems parents have long been right. Going to bed early is key to getting enough sleep and helping adolescents feel 21 , a new study reported.
A lack of sleep among youngsters may 22 depression and suicidal thoughts, according to the study by the Columbia University Medical Center.
"Our results are consistent with the theory that 23 is a risk factor for depression, working with other risk and protective factors through 24 possible causal pathways to the development of this 25 ," said lead author James Gangwisch.
"Adequate quality sleep could 26 be a preventative measure against 27 and a treatment for depression," he added in the study published in the Friday issue of Sleep magazine.
The study followed the nightly habits of some 15,659 28 , and found those who consistently went to bed after midnight had a 29 of depression than those who turned in before 10:00 p.m..
Night owls also ran a 30 higher risk of battling suicidal thoughts, the study added.
The American Academy of Sleep Medicine recommends that adolescents should sleep 31 nine hours or more a night. Those who were tucked in before 32 reported they slept on average about eight hours and 33 .
But that amount of sleep dropped significantly for those in bed 34 .
And adolescents who slept five hours or less a night were 35 more likely to suffer depression and 36 more at risk of becoming suicidal, the study said.
"It is 37 and societal expectation that adolescents do not need as much sleep as pre-adolescents, yet studies suggest that adolescents may actually require more sleep," said Gangwisch.
"Studies have found that 38 do not go to bed early enough to compensate for 39 , and transitions to earlier school start times have been shown to be associated with significant 40 ."