SHORT NOTE INTRODUCTION A NUMBER OF STUDIES HAVE SHOWN THAT TELEVISION VIEWING HAS A PROFOUND NEGATIVE EFFECT ON THE PHYSICAL AND BEHAVIORAL DEVELOPMENT OF chil-

A NUMBER OF STUDIES HAVE SHOWN THAT TELEVISION VIEWING HAS A PROFOUND NEGATIVE EFFECT ON THE PHYSICAL AND BEHAVIORAL DEVELOPMENT OF children and adolescents, specifically, increased obesity,1-3 aggressive behavior,4,5 attention deficits,6 decreased physical activity, poor physical fitness, and reduced self-esteem.7-10 Cross-sectional studies have demonstrated that television viewing may also be a risk factor for irregular sleep habits, shorter sleep duration, and sleep disorders.7,9,11-13 A longitudinal study indicated that children who watched ≥3 hours of television per day during adolescence were at a significantly elevated risk for frequent sleep problems by early adulthood.14 The study also indicated that adolescents who reduced their television-viewing from ≥1 hour/day to <1 hour/day experienced a significant reduction in risk for subsequent sleep problems.14 Other studies found that not only television viewing, but also computer game playing,7-9 internet use7,9 and children’s access to mobile phones,15 were correlated with interrupted sleep and sleep disturbances. Similar findings also have been shown in a recent study involving adults, which demonstrated that stimulating computer games may increase sleep latency and shorten REM sleep, thereby leading to a high state of arousal, a shorter duration of sleep, and poor sleep quality.16 These results suggest that the sleep behaviors of children are influenced by the current diversity of entertainment media exposure. The impact of television viewing was not demonstrated 20 years ago,17 potentially secondary to the limited exposure for the multitude of the population. A recent study revealed that 99.8% of 4to 11-year-old children in the US watch television.13 In Western countries, children aged 4-17 years old spend 16.3-29.1 hours per week on television viewing and/or other forms of entertainment, such as computer games, internet use, and movies.7,9,12,13 Due to the high prevalence and potential negative influence on the development and health of children, media use has became a public health problem.7,9,12,18 Concerns about the potential negative influence of media use on sleep behaviors should be emphasized since previous studies have illustrated that sleep plays a key role not only in children’s physical growth, behavior, and emotional development, but also is closely related to cognitive functioning, learning, and attention.12,19-21 Several hypotheses have been proposed regarding the mechanisms of association between media use and sleep disturbances. First, media use as a form of unstructured activity, which usually lacks a clear beginning and end, is likely to be extended, sacrificing sleep time, and thus shortening sleep duration.7 This sedentary form of entertainment also may alter sleep architecture16 and lead to poor quality sleep.16,22 Second, exposure to the bright The Impact of Media Use on Sleep Patterns and Sleep Disorders among SchoolAged Children in China