If you don't want to go to sleep at night, the opportunity to surf the Web and hang out with friends may be only partly to blame. According to a new study by researchers at Brown Medical School, brainwaves play a crucial role in determining when adolescents feel tired.
In a study published in the November issue of the journal Sleep, Professor of Psychiatry and Human Behavior Mary Carskadon and colleagues at the University of Zurich found that as teenagers mature, their chemically driven pressure to sleep builds up more slowly, making them feel tired later.
The study looked at the brainwaves, or electroencephalograms, of seven young children and six adolescents during 36 hours of sleep deprivation. While previous studies have attributed adolescents' problems with bedtime to changes in the brain's internal clock, this new study shows that a slower buildup of sleep pressure is also responsible.
The 13 healthy children had all participated in previous sleep studies at Bradley Hospital, where the research was conducted. After confirming that they had gotten 10 hours of sleep per night for the previous 10 days, the children were required to sit up in bed for the entire 36 hours. College interns kept them company, playing board games and watching films with them and administering written tests.
"It was a struggle at certain times, especially between six and nine in the morning. That is a rough time if you have been up all night," Carskadon said. "But they loved every minute of it ... in part because of the 15 college students who work one-on-one with these kids in the lab. The kids got a lot of quality time with a lot of bright young adults."
The late-night habits of teenagers raise important questions for schools, parents and students. In order to accommodate students' late-night study habits, Brown has recently extended the hours of service in libraries and cafes and is planning construction of a 24-hour study center in the Sciences Library mezzanine.
In a letter to the editor published in The Herald in September, Carskadon wrote, "Nocturnal social interplay (if not rites and rituals) also has a rich place in college students' lives ... in bull sessions, parties and hair-down banter. Yet, to encourage serious academic pursuits in the dead of the night (why is it called 'dead' do you think?) does not promote serious consideration of healthy sleep ... even a one-hour extension of closing time of The Gate drained student workers. I like the idea of keeping students' nocturnal activities dorm-focused."
According to Carskadon, in a study of Brown students done "some years ago," the median time that undergraduates went to sleep was 2 a.m.
Dan Ludwig '09 is enrolled in Carskadon's course, PY 55: "Introduction to Sleep," and has changed his sleep habits as a result.
"I learned that I need 8.4 hours of sleep or I will be in a state of disarray," Ludwig said. "I will be disoriented, I will lack motivation. ... Knowing this, I now make a point to go to bed early - about 12:30 during the week."
Carskadon said that just because teens don't feel tired until later at night doesn't mean that they shouldn't go to bed. She suggested parents help set bedtimes and also pointed out that some parents and students try to compromise on sleep in order to stay competitive for the college admission process. "Some parents buy into that idea of 'My kid has to do everything and excel in everything if they want to go to Brown,' but in fact, they only have to excel in some things, so there is time for sleep," she said.
Nevertheless, many secondary schools have discussed starting later in the day. Ludwig agreed that it has been much easier for him to get a good night's sleep in college than in high school because of the later start times for classes.
According to the Registrar's Office, only one class at Brown starts at 8 a.m. this semester, though 21 classes start at 8:30.
"I'm a little sleep-centric - or maybe a lot sleep-centric - but it really forms a fundamental basis for the rest of our lives and for waking," Carskadon said, citing depressed moods, impaired learning, behavioral problems and an increase in risk-taking as a few of the consequences of not getting enough sleep.
Students can also work to ensure they are getting a good night's sleep. "Have a plan, know how much sleep you need and make a regular schedule. Get lots of light in the morning but less in the evening, and try not to drink caffeine within eight to 10 hours of bedtime," she said.
