Health & Welfare, K–12 | Daily Report

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High school students who sleep less than the recommended eight hours per night – about 70 percent nationwide – are more likely to engage in risky health behaviors such as smoking and drinking, according to a new study by the Centers for Disease Control and Prevention.

Sleep-deprived students also were more likely than their well-rested counterparts to drink soda daily, be sexually active, have seriously considered suicide and have gotten into a physical fight within the last year. They were less likely to be physically active, and they tended to spend longer hours on computers.

The study is based on the 2007 Youth Risk Behavior Survey – the first to include sleep duration data. The survey includes more than 12,000 public and private high school students nationwide.

Published online last week in the journal Preventive Medicine, the findings highlight the need for public health intervention, said the study's lead author, Lela McKnight-Eily.

"People have largely a perception (that) sleep is this luxury," said McKnight-Eily, an epidemiologist at the CDC's Division of Adult and Community Health. "They see their kids sleeping and think that they're being lazy. We definitely have to try to change our messaging to help people understand that sleep is a necessity – like eating well and exercising."

A good night's sleep is important at all ages, but insufficient sleep among high schoolers is particularly concerning, McKnight-Eily said.

"Adolescence is a particularly sensitive time for the initiation of a lot of risk behaviors," she said.

For example, people often start cigarette smoking as teenagers. According to the study, among students who got insufficient sleep, 24 percent smoked cigarettes on at least one day in the past 30 days. Among students who slept at least eight hours a night, 15 percent smoked cigarettes.

Increasing the number of hours students sleep is one reason many schools, including several in California, have pushed back the start of the school day. Research has linked improvements in sleep durations, mood and health to starting school 30 minutes later. 

Prevalence of health-risk behaviors by hours slept on an average school night. Click image to enlarge.

In 2004, a student advisory board from the California Association of Student Councils sought to have schools start at 8:40 a.m.

"Students are negatively affected by early start times with regard to attendance, academic performance and behavior problems," the students wrote. "When students are well rested … (they) will be more alert and attentive during school. Students will be more likely to learn more because they will approach school with a more positive attitude."

The proposal [PDF] failed to gain legislative backing. Even without school policy changes, though, students and their families can make changes to improve sleep, McKnight-Eily said. 

Students can set a regular sleep schedule and remove from their bedrooms anything that might keep them awake at night. They also should avoid eating heavy meals and drinking caffeine before going to sleep. For students with chronic sleep problems, families might consider seeking the advice of a health professional, McKnight-Eily said.

Getting a full night's sleep, she said, "makes a big difference."