THURSDAY, Feb. 18 (HealthDay News) — Young drivers who are overtired from lack of sleep or poor quality sleep are twice as likely to have a car crash, Italian researchers report.
“We think that adolescents should simply not drive while sleep-deprived, therefore sleep deprivation should be avoided, especially when driving is expected,” said lead researcher Dr. Fabio Cirignotta, a neurology professor at the University of Bologna.
For the study, Cirignotta’s team collected data on 339 Italian students, aged 18 to 21 (mean age 18.4 years), who had driver’s licenses. The students were asked about their sleep habits and traffic accidents.
The researchers found that 80 students had had at least one car accident. Of those, 56 percent said they had driven while sleepy and 15 percent said sleepiness was a prime cause of the accident.
Cirignotta’s group found that the young drivers were chronically sleep-deprived. While the students reported needing more than nine hours of sleep a night, they also reported sleeping only an average of 7.3 hours on weeknights.
Only 6 percent of the students said they got the needed 9.2 hours of sleep on weeknights. Most, 58 percent, said they tried to catch up on sleep on the weekend, the researchers found.
The students also reported a variety of sleep problems, including waking up during the night (45 percent), difficulty waking up in the morning (40 percent) and “bad sleep” (19 percent).
Moreover, 64 percent of the students said their lack of sleep made them sleepy during the day.
In addition to lack of sleep, men were more prone to accidents than women, as were those who smoked. The researchers speculate that smoking may be related to trying to stay awake and alert while driving.
“Our findings point to the fact that young people frequently show poor sleep habits, mainly sleep deprivation, and their poor sleep hygiene is reflected by impaired daytime vigilance and performances,” Cirignotta said.
“If an adolescent, or an adult, feels sleepy while driving, the only efficacious countermeasure is to stop driving immediately in a safe environmental condition and sleep for 10 to 15 minutes,” he said.
All other commonly used countermeasures, such as opening the window, listening to the radio or drinking coffee, are known to be short-lasting and, essentially, useless, Cirignotta added.
“Moreover, if a subject perceives sleepiness, he/she would probably already have a reduced performance at the wheel, and nobody can safely detect the real instant when sleep is starting in order to stop driving at that time,” he said.
The report is published in the Feb. 15 issue of the Journal of Clinical Sleep Medicine.
Dr. Shahriar Shahzeidi, an associate professor of pediatrics in the division of pulmonary and sleep medicine at the University of Miami Miller School of Medicine, said that overtired drivers are “in a twilight zone” and many in the United States are driving when they are overtired.
Particularly, between 2:00 and 4:00 in the afternoon, overtired drivers are in a state called “sleep latency,” he said. In this state, they are narcoleptic and can fall asleep within three minutes even if they are at the wheel.
“If you don’t sleep enough or are sleep-deprived, your body is going to pay one way or another,” Shahzeidi added. “It is usually when you are doing a monotonous thing like driving. Five minutes is enough — the sound of the road and the monotony of sitting — that five minutes is enough to go to sleep.”
For more on teens and safe driving, visit the U.S. National Library of Medicine.