Use of Mobile Phones and Sleep Disturbances in Adolescents: Round-the-Clock Accessibility

Over the past few years, especially after the introduction of smartphones on the market, the use of mobile phones has become almost incessant.  The need to be accessible at any time and to respond immediately to what is happening all around, make it difficult to cut oneself off from the device even for limited periods, such as during sleep.  


Together with nutrition and physical activity, sleep is a vital component for maintaining good health.  Studies have shown that lack of sleep disrupts the body's biological clock and affects the body's metabolic function.  Sleep is essential for the normal functioning of various body systems, especially the nervous system.  During sleep, processes essential to building up memory take place. It was found recently, in mouse studies, that the body takes advantage of sleep to eliminate from the brain neurotoxic wastes that accumulated during the day and could harm the nervous  system.  

     A teenager lying in bed, holding a mobile phone
Lack of sleep affects learning ability, concentration, and mood changes, and gives rise to symptoms of tension and anxiety.  A person who did not have sufficient sleep during the night will be tired during the day, thus affecting behavior and performance. Sleep is also necessary for the normal functioning of other body systems, such as the immune system and the endocrine (hormonal) system.


In children and adolescents, who are going through stages of growth and development, sleep is particularly vital.  Various studies have shown that adolescents need about 8.5-10 hours of sleep each night, while in practice the average duration of sleep for most of them is much shorter, especially on school days.  One of the main reasons for postponing bedtime and for the lack of sufficient sleep hours is the widespread use of communications technologies, such as TV, computers and mobile phones.  Over the past decade there has been a dramatic increase in the use of mobile phones among adolescents:  the Pew Research Institute reported that in 2012, 78% of adolescents (aged 12-17) in the USA possessed a mobile phone, compared with 45% in 2004.  One in every four adolescents uses a smartphone today as the principal device for going online, and text messages have become the chief mode of communication among youngsters in that age group.  According to this report, the average adolescent will send about 100 text messages a day, and 84% of the adolescents sleep with the mobile phone in their bedrooms.



Various studies have investigated the effect of mobile phone use on sleep routines.  Researchers hypothesized that the need of adolescents to be accessible at all times, even at night, might affect duration and quality of sleep.  



A study published in 2014 investigated whether mobile phones interfere with adolescent sleep in 454 American subjects aged 12-20 (average age 15).  The results showed that more than half of them (63%) took their phones to their bedrooms, 57% left the phone on while they slept, and more than one-third (37%) sent text messages after they had initially fallen asleep.  Almost half (46%) used the phone as an alarm clock at least twice a week, and 8% woke up to a text message after they had fallen asleep.



Another study, published in 2011, analyzed about 95,000 questionnaires completed by Japanese high school students to examine their habits in the use of mobile phones.  This study showed an association between the use of mobile phones after going to sleep, and sleep disturbances in adolescents, expressed as shorter sleep duration, lower quality of sleep, and symptoms of insomnia.



An additional study, based on 236 questionnaires and 'sleep logs' completed over one week by students at an American college, showed that more than 40% responded to text messages or phone calls after going to sleep.  This study reported poorer sleep quality compared with that of students whose sleep had not been disturbed through the use of a mobile phone, as well as symptoms of anxiety and depression, including lack of concentration, low energy level, and fatigue during the day.



During the conduct of these studies, the researchers faced a number of challenges related to research methodology:

  • The need to rely on self-reporting by the research subjects.
  • Separation of the effect of the use of one type of technological device (the mobile phone) from the use of other devices used concurrently (computers, TV).
  • Separation of the use of one component of the mobile phone (text messaging or conversing) from another (such as passive listening to music).


Various companies have lately developed experimental tools, among them mobile phone applications that would enable objective recording of the parameters related to sleep and the use of this device.  It is hoped that these will lead to a broadening of the research frameworks and to a better understanding of the effect of this technology on sleep.





The use of mobile phones is an established fact.  This technology will undoubtedly develop additional uses related to our daily routine.  It is our responsibility as users to set the limits.  One of the issues that require restrictions is the use of mobile phones during sleep hours, especially by children and adolescents, for whom sleep hours are particularly critical.  Lights-out in the bedroom should be accompanied by switching off the phone and disconnecting from what is happening all around.  Otherwise, the mobile phone user who is accessible around the clock will pay a price, both as to duration and quality of sleep, and to exposure to non-ionizing radiation emitted by the device if it is located near the body during sleep.