Cross-lagged associations between sleep and technology in adolescents: Are teens using technology as a sleep aid or is technology disrupting their sleep?

Sleep duration decreases from puberty throughout adolescence. This decrease is normative and is due to both biological and psychosocial changes that push adolescents´ bedtimes later. However, there are indications that a decrease in sleep duration in adolescents have worsened during the last 20 years (Maslowsky et al., 2014). So, biological changes do not explain the current decline in sleep duration fully. One mechanisms that has been hypothesized explaining this change is the development of new technologies and internet accessibility around the clock. However, the majority of studies investigating the relationship between poor sleep and technology use at bedtime are cross-sectional. Thus, it cannot be excluded that adolescents use technology because they cannot fall asleep. Therefore, the aim of this study was to test whether technology use at bedtime predicted longer sleep onset latency (= time to fall asleep), or vice versa using cross lagged analyses over a 3-year period. Participants were high school students in the 7th and 8th grade (N = 2552; age range: 12-15 years, at baseline) from 17 public schools in three communities in middle Sweden. Students filled out questionnaires in school during the spring, 2014 (T1), 2015 (T2) and 2016 (T3) (85% retention rate). Survey data included one question about technology use at bedtime and sleep onset latency (SOL). Technology use at bedtime significantly predicted longer SOL and vice versa from T1 to T2. From T2 to T3 sleep predicted technology use but not vice versa. This is the first study to investigate the reciprocal association between sleep and technology use in an adolescent population. It seems as technology use at bedtime and long sleep onset latency perpetuate each other in early adolescence, but later on it might be that adolescents who have a sleep problem use technology as a way to cope with it.