title: What's Keeping Teenagers Up? Prebedtime Behaviors and Actigraphy-Assessed Sleep Over School and Vacation.
abstract: OBJECTIVE
  Technology-related behaviors (e.g., computer use) before bedtime (BT) have been associated with poorer and shorter sleep in adolescents; however, less is known about other behaviors in relation to sleep. This study characterized a range of behaviors in the hour before bed (i.e., pre-BT behaviors [PBBs]) and examined their relationship with sleep parameters during school and vacation periods (i.e., restricted and extended sleep opportunities, respectively). Mechanistic roles of chronotype and cognitive presleep arousal (PSAcog) were also examined.
  
  
  METHODS
  During the last week of a school term and throughout a 2-week vacation, 146 adolescents (47.26% male, age M ± standard deviation = 16.2 ± 1.0 years) from the general community completed daily sleep measure using actigraphy, self-report measures on PBBs and PSAcog (Presleep Arousal Scale) for both school and vacation periods, and chronotype (Morningness-Eveningness Questionnaire).
  
  
  RESULTS
  Adolescents engaged in a variety of behaviors before bed. Notably, playing video games was associated with significantly later school and vacation BT and shorter school sleep duration (controlling for chronotype). During vacation, online social media was associated with significantly longer sleep onset latency, and this relationship was mediated by higher PSAcog. In contrast, on school nights, spending time with family was associated with significantly earlier BT and longer sleep duration.
  
  
  CONCLUSIONS
  Technology-related PBBs video games and online social media were risk factors for shorter and poorer sleep, whereas time with family was protective of sleep duration. In addressing sleep problems in adolescents, therapeutic procedures that target the potentially addictive nature of technology use and reduce PSAcog were implicated.
authors.affiliation: Institute of Cognitive and Clinical Neurosciences, School of Psychological Sciences, Faculty of Biomedical and Psychological Sciences, Monash University, Victoria, Australia.
authors.forename: Emily
authors.initials: E
authors.lastname: Harbard
authors.affiliation: Melbourne School of Psychological Sciences, University of Melbourne, Victoria, Australia; Department of Psychology, University of Oregon, Eugene, Oregon.
authors.forename: Nicholas B
authors.initials: NB
authors.lastname: Allen
authors.affiliation: Melbourne School of Psychological Sciences, University of Melbourne, Victoria, Australia.
authors.forename: John
authors.initials: J
authors.lastname: Trinder
authors.affiliation: Institute of Cognitive and Clinical Neurosciences, School of Psychological Sciences, Faculty of Biomedical and Psychological Sciences, Monash University, Victoria, Australia; Department of Psychiatry, Centre for Women's Mental Health, Royal Women's Hospital, University of Melbourne, Victoria, Australia. Electronic address: bei.bei@monash.edu.
authors.forename: Bei
authors.initials: B
authors.lastname: Bei
mesh_terms: D056044:Actigraphy / Q000379:methods; D000293:Adolescent; D000294:Adolescent Behavior; D002940:Circadian Rhythm / Q000502:physiology; D003201:Computers / Q000706:statistics & numerical data*; D005260:Female; D006693:Holidays; D006801:Humans; D008297:Male; D012574:Schools; D057566:Self Report; D012890:Sleep / Q000502:physiology*; D061108:Social Media / Q000706:statistics & numerical data; D011795:Surveys and Questionnaires; D013997:Time Factors
keywords: Adolescents; Bedtime; Chronotype; Family; Prebedtime behaviors; Presleep arousal; School-term; Sleep duration; Social media; Vacation