Late nights might make teenagers more prone to depression and suicidal thoughts by depriving them of sleep, according to a study by researchers at Columbia University.
Teens whose parents let them go to bed past midnight were 24 percent more likely to be depressed and 20 percent more likely to have contemplated suicide than peers whose parents set bedtimes at or before 10 p.m., the researchers said Friday in the journal Sleep.
The study is the first to show that sleep deprivation might cause depression and suicidal thoughts in adolescents. Previous research has shown a link, though the relationship wasn’t clear because insomnia can be a symptom of depression.
“Our results strengthen the argument that lack of sleep can cause depression as opposed to simply being a symptom of depression,” James Gangwisch, the study’s lead author and an assistant professor at the university’s medical center, said in an e-mail.
Gangwisch and colleagues studied data from 15,659 U.S. students who were in grades seven to 12 between 1994 and 1996, and their parents.
Teenagers whose parents said they should go to bed at 10 p.m. or earlier slept for 8 hours 10 minutes on average — 40 minutes more than those with bedtimes set at midnight or later, the researchers found.
Those who slept for five hours or less each night were 71 percent more likely to have depression and 48 percent more likely to have thought about suicide than those who got eight hours of sleep, according to the study, funded by Columbia University.
