Protective and Risk Factors for Adolescent Sleep Health

Author: Kate Bartel

Bartel, Kate, 2017 Protective and Risk Factors for Adolescent Sleep Health, Flinders University, School of Psychology

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There is consensus among the scientific community that adolescence is a unique developmental period, and that good sleep health is required for optimal functioning and positive development. Factors associated with bedtime, the time it takes to fall asleep (sleep latency), and sleep duration have been studied, particularly in relation to weekday sleep, when school start time and biological sleep patterns conflict with adolescents’ sleep need. Generally, these factors may be categorised as promoting (protective) or disrupting (risk) sleep health. Yet, often, studies are correlational, a limited number of protective and risk factors are studied at one time, and samples are contained within country, or continent.

To address this gap in literature, this thesis introduced the topic of adolescent sleep, before looking in detail at behavioural protective and risk factors for bedtime, sleep latency and total sleep time, with a focus on weekday sleep. Firstly, in Chapter 2, this was done through a comprehensive meta-analysis, whereby multiple behavioural factors were examined in one chapter. This allowed comparative assessment of the strength of association between each factor and adolescent sleep. Based on these findings, the third and fourth chapters examined factors found to be associated with adolescent sleep, through an international, online survey. Chapters 3 and 4 enabled assessment of these associations, after controlling for other possibly related variables, across continents and hemispheres.

As technology use was found to be a risk factor for bedtimes in the earlier chapters, Chapter 5 experimentally manipulated pre-bed mobile phone use. Restriction of mobile phone use in the hour before bed tested the causal relationship between pre-bed phone use and adolescent sleep, with earlier lights out time (17 min) and longer sleep (19 min) resulting during the intervention week. In contrast, Chapter 6 focussed on protective factors determined in earlier chapters, as good pre-sleep cognitive emotional arousal was related to shorter sleep latency. Adolescents were allocated to one of three conditions (mindfulness body scan, constructive worry, control) to determine the effects of brief, 15 min interventions on decreasing pre-sleep worry, and thus sleep latency. Mindfulness decreased sleep latency by 31 min among adolescents with a baseline sleep latency of 30 min or longer, but no other significant effects were found.

Findings are summarised in Chapter 7, giving consideration to methodological, theoretical and clinical implications. An emergent theme throughout the thesis was that of good sleep hygiene being a strong helpful factor for advancing bedtime, decreasing sleep latency, and increasing sleep duration. Technology use, particularly close to bedtime, was related to later bedtimes, yet not to sleep latency. It can thus be considered a contributor to poor sleep, but not a sole focus. This thesis gives guidance into the most meaningful ways to assist adolescents in the general population to improve their sleep, through advancing bedtimes, decreasing sleep latency, and increasing sleep duration. This can be through reducing risk factors (e.g., pre-bed mobile phone use, evening light) or implementing protective factors (e.g., good sleep hygiene, mindfulness body scan at bedtime). Findings as they pertain to practical assistance for adolescents, as well as their caregivers, are discussed.

Keywords: Adolescent, sleep, protective factors, risk factors, sleep latency, bedtime, sleep duration, technology, mobile phone, daylength, mindfulness, pre-sleep arousal

Subject: Psychology thesis

Thesis type: Doctor of Philosophy
Completed: 2017
School: School of Psychology
Supervisor: Michael Gradisar