Text messaging as a cause of sleep interruption in adolescents, evidence from a cross‐sectional study

There is a small, but growing body of research looking at the impact of the mass media on young people’s sleep patterns. Lack of sleep and nightmares have been linked to television viewing (Van den Bulck, 2000). Sleep disturbances have been linked to the presence of a TV set in the child’s bedroom (Owens et al., 1991) and to computer game play (Tazawa and Okada, 2001). Media for interpersonal communication, however, appear not to have received similar attention. Increasingly, young children and adolescents have the use of a personal mobile phone, which they use a lot for text messaging (referred to as SMS). Some parents reported to the author that their children take their mobile phones to bed with them and leave them switched on to make sure they do not miss any incoming calls or messages. We added the question How often are you woken up at night by incoming text messages on your mobile phone? to the first wave of the Leuven Study on Media and Adolescent Health (SOMAH). Answer categories were (1) Never; (2) one to three times a month; (3) about once a week; (4) several times a week; (5) every day. Respondents were 2546 adolescents from the first and fourth grade of 15 randomly selected secondary schools in Flanders, Belgium; 50.2% of the sample were first-grade children. In the first grade the average age was 13.16 years (SD 1⁄4 0.43) and in the fourth grade the average age was 16.37 years (SD 1⁄4 0.71); 54.2% were boys. An analysis of variance was performed to determine whether significant differences existed between boys or girls and between first and fourth graders. A post hoc Tukey test at the P < 0.05 significance level, showed that significant differences existed between grades, but not between boys and girls. In the first grade, 73.3% of the respondents reported never to be disturbed in their sleep by incoming messages; 13.4% reported being woken up one to three times a month, 5.8% were woken up once a week, 5.3% were woken up several times a week and 2.2% were woken up every day. In the older, fourth grade, group 56.7% said their sleep was never interrupted by incoming messages; 20.8% was woken up between one and three times a month, 10.8% was woken up at least once a week, 8.9% was woken up several times a week and 2.9% was woken up every day. We asked the respondents to indicate how tired they felt in five conditions: (1) generally speaking, (2) in the morning when they got up, (3) at school, (4) after a day at school and (5) after the weekend. Answers were on an 11-point scale ranging from )5 (not tired at all) to +5 (extremely tired) with 0 as a neutral middle. In the first grade those respondents who reported being woken up by text messages at least occasionally were significantly more tired than those who were never woken up by messages (1) generally speaking, (3) at school and (5) after the weekend. In the fourth grade, those whose sleep was interrupted at least occasionally reported being tired significantly more on all five variables. These preliminary findings suggest that mobile telephones may be having a major impact on the quality of sleep of a growing number of adolescents. It affected a quarter of the youngest to almost half of the eldest children in the sample. The threat to healthy sleep patterns is potentially more important than the threat posed by entertainment media. The latter mainly appear to influence time to bed, while mobile phones actually seem to lead to interrupted sleep.