LEUVEN, Belgium, Sept. 4 -- Just because adolescents go to bed, that doesn't mean they stop calling and texting their friends, and that may leave them bleary-eyed in the morning, researchers here reported.
Adolescents who use their mobile phones for calling friends and sending and receiving text messages after bedtime awaken sleep-deprived and tired, Jan Van den Bulck, Ph.D., of Katholieke Universiteit Leuven here, reported in the Sept. 1 issue of Sleep.
Heavy use of TV, internet, and computer games in the bedroom has been linked to reduced time in bed and to sleep disturbances, although adolescents often claim they need these media as "sleep aids."
Much of the teen use of cell phones involves the simple pleasure of being permanently connected, day and night, to a group of friends, Dr. Van den Bulck said. However, he added, little has been known about the impact of cell phone use on sleep.
To assess the prevalence of night-time mobile phone use and its relationship to tiredness with a one-year follow-up, Dr. Van den Bulck studied 1,656 second-year and fifth-year secondary school children in 15 schools in Flanders.