Associations between screen time and short sleep duration among adolescents varies by media type: evidence from a cohort study

Different types of electronic screen media have repeatedly been linked to impaired sleep; yet, how different uses of electronic media are linked to sleep has received much less attention. Currently, the role of chronotype in these associations is understudied. To address these gaps, this study examined how different uses of screen media are linked to sleep, and whether these associations were accounted for or differed across chronotype. Data were from 11,361 children aged 13 to 15 from the United Kingdom who participated in the 2015 wave of the Millennium Cohort Study. Heavy use of screen media was associated with shorter sleep duration, longer sleep latency, and more mid-sleep awakenings. The strongest associations emerged for using screen media to engage in social media or to use the internet. Overall, these associations were weakened, but remained after controlling for chronotype and tended to be the strongest amongst robins (children with an intermediate chronotype). Spending too much time on electronic devices is associated with multiple dimensions of impaired sleep, especially if this time on devices is used for social media or surfing the internet. Chronotype does not account for the associations between screen media and sleep and can be used to identify children who may be particularly susceptible to the effects of screen media on sleep.