*The following is excerpted from an online article from HealthDay.
More than 90 percent of American high school students are chronically sleep-deprived, putting their health and academic performance in jeopardy, a new report finds.
The study, based on U.S. national data, finds that most teens don't get the minimum 9 to 10 hours of sleep per night that's recommended by standard guidelines.
Teenagers do face a number of challenges as they try to get adequate sleep, experts say.
"I don't believe there's one culprit," said the study's lead author, Charles Basch, a professor of health and education at the Teacher's College at Columbia University in New York City.
"For some children it's too much homework, for some it's health problems like asthma," he explained. "For others it may be anxiety or depression, or the prescription medications they are taking for such conditions. Recreational drugs can be a factor, as can having electronics in the bedroom."
In the study, the researchers tracked findings from four U.S. government surveys conducted in 2007, 2009, 2011 and 2013 as part of the Youth Risk Behavior Surveillance System.
Each year, between roughly 12,000 to 15,000 students in grades 9 through 12 were asked about how many average hours of sleep they got each school night.
Overall, less than 10 percent of teens said they were actually meeting current U.S. Centers for Disease Control and Prevention guidelines for sleep. Only about 7 percent of girls, and around 8 to 9 percent of boys said they got nine to 10 hours of sleep per night.
And, for the most part, sleep patterns for teenagers appeared to get worse with age -- surveys showed that by the time they reached 12th grade, a whopping 95 percent of high school seniors were not routinely meeting CDC sleep guidelines.
Girls tended to fare worse than boys, with girls being more prone to sleep five hours or fewer per night and less likely to get nine or more hours of sleep each night, the study found.
According to Basch, early school start times are one major reason behind all those sleepless teens.
"More and more attention is being focused on the start times of schools, with the idea being that very early class schedules do not serve good sleep patterns," he said.
The new study is published in the December issue of the CDC journal Preventing Chronic Disease.