Compared to students who go to sleep early, teenage night owls are more prone to academic and social difficulties in the long-run, according to new research from the University of California at Berkeley.
Data from a nationally representative sample of 2,700 US teenage students aged 13 to 18 revealed that 30 percent reported going to bed at 11:30 p.m. or later on school nights and 1:30 a.m. or later when school was not in session for the summer.
By the time the adolescent night owls finished high school, they had lower grade point averages and were more vulnerable to emotional problems than their peers with earlier bedtimes, according to the researchers, who published their work in the Journal of Adolescent Health.
The researchers said their study offers a "compelling argument in favor of later middle and high school start times in the face of intense academic, social and technological pressures."
"Academic pressures, busy after-school schedules, and the desire to finally have free time at the end of the day to connect with friends on the phone or online make this problem even more challenging," said Lauren Asarnow, lead author of the study and a graduate student in UC Berkeley's Golden Bear Sleep and Mood Research Clinic.
Asarnow also said the research points to the positive academic and emotional benefits of a good night's sleep.
To reach their conclusions, Asarnow and her colleagues used data from the National Longitudinal Study of Adolescent Health. They also observed that while going to bed late in the summer when there was no school did not impact academic achievement, including grades, there was a correlation between later summer bedtimes and emotional problems in young adulthood.
A number of surveys suggests that many teenager do not get adequate sleep, perhaps because upon the onset of puberty the human circadian rhythm, which regulates physiological and metabolic functions, shifts to a later sleep cycle.
The researchers hypothesize that a preference for later bedtimes is a confluence of biological factors, parental influence, academic and social pressures and the use of electronic gadgets. Late night use of electronic devices with bright screens such as smartphones, tablets and laptops, for example, have been found to suppress melatonin, a hormone that helps regulate the sleep cycle.
Allison Harvey, a UC Berkeley psychologist and senior author of the paper, said the study adds to a wealth of evidence that teenage night owls are "at greater risk for adverse outcomes" in life.
"Helping teens go to bed earlier may be an important pathway for reducing risk," she said.