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Less sleep linked to youth smoking and drinking

Published: 19 Dec. 2011, 00:08

At a high school in Seoul’s Gwangjin District, a 17-year-old student surnamed Kim studies until 5 a.m. in preparation for final exams and is one of many adolescents nationwide who are sleep deprived, getting only four hours of sleep a night. Because of sleep deprivation, he has become increasingly agitated and is more likely to lash out at his parents and friends.

Even when it’s not exam time, he usually gets just five hours of sleep a night. Consequently, he resorts to napping at school any chance he gets, often sleeping on his desk.

Kim admitted, “Sometimes it becomes so unbearable I feel like causing an accident.”

Recent studies show that adolescents who sleep less have a higher chance of showing deviatory behavior, such as drinking and smoking.

The Korea Centers for Disease Control and Prevention revealed last week the results of its 2011 online study on youth behavior, which surveyed 80,000 students from the first year of middle school to senior year of high school, from 800 schools nationwide.

According to the study, the average amount of sleep for middle school students was seven hours and five minutes and for regular high school students five hours and 32 minutes. Meanwhile, the average time students in vocational high schools spend sleeping was slightly higher at six hours and 13 minutes.

But this falls well short of the eight hours recommended by the National Sleep Foundation, a U.S. nonprofit organization, for adolescents. In comparison, U.S. middle schoolers get an average of eight hours and 12 minutes of sleep per night, while U.S. high schoolers get on average seven hours and 12 minutes per night.

But 74.8 percent of middle school students, 97.7 percent of regular high school students and 89.8 percent of vocational school students did not reach the recommended amount in Korea.

Kim Yun-jeong, researcher at the Korea Centers for Disease Control and Prevention, said, “Attending hagwon late into the night, having part-time jobs and playing online games have contributed to the decrease in adolescents’ sleeping hours.”

The studies indicated that lack of sleep also had the negative influence of inciting adolescents to become more vulnerable to the temptations of smoking and drinking.

Six percent of middle schoolers who sleep an average of eight hours a night smoked, and 10.4 percent of them had consumed alcohol. But among middle schoolers who sleep on average less than five hours a night, 10.1 percent smoked and 20.1 percent drank.

The study further showed that sleep deprivation was correlated to higher suicidal impulses.

Dr. Hong Seung-bong, neurologist at Samsung Medical Center, said, “When you are deprived of sleep, stress-inducing hormones like cortisol are secreted excessively, which leads to emotions being unstable and a higher chance of depression.”

Among middle schoolers who get less than five hours of sleep a night, 61.8 percent claimed to “regularly feel a lot of stress” and 33.5 percent said they had seriously considered suicide in the past year. In contrast, only 32.4 percent of middle school students who sleep eight hours per night said they “feel a lot stress,” and 15.4 percent said they had seriously considered suicide.

By Park Yu-mi [[email protected]]