Adolescents' trajectories of depression and anxiety symptoms prior to and during the COVID-19 pandemic and their association with healthy sleep patterns.

The COVID-19 pandemic has seen a rise in anxiety and depression among adolescents. This study aimed to investigate the longitudinal associations between sleep and mental health among a large sample of Australian adolescents and examine whether healthy sleep patterns were protective of mental health in the context of the COVID-19 pandemic. We used three waves of longitudinal control group data from the Health4Life cluster-randomized trial (N = 2781, baseline Mage = 12.6, SD = 0.51; 47% boys and 1.4% 'prefer not to say'). Latent class growth analyses across the 2 years period identified four trajectories of depressive symptoms: low-stable (64.3%), average-increasing (19.2%), high-decreasing (7.1%), moderate-increasing (9.4%), and three anxiety symptom trajectories: low-stable (74.8%), average-increasing (11.6%), high-decreasing (13.6%). We compared the trajectories on sociodemographic and sleep characteristics. Adolescents in low-risk trajectories were more likely to be boys and to report shorter sleep latency and wake after sleep onset, longer sleep duration, less sleepiness, and earlier chronotype. Where mental health improved or worsened, sleep patterns changed in the same direction. The subgroups analyses uncovered two important findings: (1) the majority of adolescents in the sample maintained good mental health and sleep habits (low-stable trajectories), (2) adolescents with worsening mental health also reported worsening sleep patterns and vice versa in the improving mental health trajectories. These distinct patterns of sleep and mental health would not be seen using mean-centred statistical approaches.

A bidirectional model of sleep and technology use: A theoretical review of How much, for whom, and which mechanisms.

The link between technology and sleep is more complex than originally thought. In this updated theoretical review, we propose a new model informed by the growing body of evidence in the area over the past 10 years. The main theoretical change is the addition of bi-directional links between the use of technology and sleep problems. We begin by reviewing the evidence to date for the originally proposed mechanisms of bright light, arousal, nighttime sleep disruptions, and sleep displacement. Then, in support of the new direction of effect (sleep problems preceding technology use), we propose two new mechanisms: technology before sleep might be used as a time filler and/or as an emotional regulation strategy to facilitate the sleep-onset process. Finally, we present potential moderators of the association between technology and sleep, in recognition of protective and vulnerability factors that may mitigate or exacerbate the effects of technology on sleep and vice versa. The goal of this theoretical review is to update the field, guide future public health messages, and to prompt new research into how much technology and sleep affect each other, for whom it may be problematic, and which mechanisms may explain their association.

Technology use as a sleep-onset aid: are adolescents using apps to distract themselves from negative thoughts?

Study Objectives: The aim of this study was to; (1) explore whether adolescents use technology as distraction from negative thoughts before sleep, (2) assess whether adolescents who perceive having a sleep problem use technology as distraction more compared to adolescents without sleep complaints, and (3) collect qualitative information about which devices and apps adolescents use as a distraction. Methods: This study used a mixed-methods cross-sectional design, where 684 adolescents (M = 15.1, SD = 1.2, 46% female) answered both quantitative and qualitative questions about their sleep (perceived sleep problem, sleep onset time (SOT), and sleep onset latency [SOL]) and technology use as distraction from negative thoughts. Results: The majority of adolescents answered "yes" or "sometimes" using technology as a distraction from negative thoughts (23.6% and 38.4%). Adolescents who answered "yes" to using technology as distraction were more likely to report having a sleep problem, longer SOL, and later SOT, compared to adolescents who answered "no". The most popular device to distract was the phone, because of its availability, and the most common apps used for distraction included YouTube, Snapchat, and music apps. Conclusions: This study shows that many adolescents use technology to distract themselves from negative thoughts, which may help them manage the sleep-onset process. Thus, distraction may be one mechanism explaining how sleep affects technology use, rather than vice versa.

Sleep's role in the development and resolution of adolescent depression.

Two adolescent mental health fields - sleep and depression - have advanced largely in parallel until about four years ago. Although sleep problems have been thought to be a symptom of adolescent depression, emerging evidence suggests that sleep difficulties arise before depression does. In this Review, we describe how the combination of adolescent sleep biology and psychology uniquely predispose adolescents to develop depression. We describe multiple pathways and contributors, including a delayed circadian rhythm, restricted sleep duration and greater opportunity for repetitive negative thinking while waiting for sleep. We match each contributor with evidence-based sleep interventions, including bright light therapy, exogenous melatonin and cognitive-behaviour therapy techniques. Such treatments improve sleep and alleviate depression symptoms, highlighting the utility of sleep treatment for comorbid disorders experienced by adolescents.

Sleep phase and pre-sleep arousal predicted co-developmental trajectories of pain and insomnia within adolescence.

The onset of both chronic pain and insomnia is high during adolescence. Although a bidirectional relationship between pain and insomnia has support, how pain and sleep co-develop throughout adolescence remains unknown. Sleep-wake patterns, pre-sleep behavior and pre-sleep arousal may influence the co-development of pain and insomnia. Four waves of longitudinal self-report data were used (Nbaseline = 2767, Agebaseline M = 13.65 years, SD = 0.65). Multidimensional growth mixture modeling was used to identify four subgroups of adolescents with different concurrent trajectories of pain and insomnia. The trajectories followed each other across time in all classes: one class of consistently low pain and insomnia (68.7%), one class with persistent high symptoms (4.9%), as well as one class of increasing (13.9%), and one of decreasing (12.5%), trajectories. Later sleep-wake patterns and more pre-sleep cognitive-emotional arousal predicted both increasing and decreasing trajectories of concurrent pain and insomnia. The current study showed that developmental trajectories of pain and insomnia follow each other within adolescents and across adolescence. Both sleep-phase focused interventions as well as psychological interventions that focus on pre-sleep cognitive-emotional arousal may prove beneficial for adolescents with comorbid pain and insomnia.

Trajectories of insomnia symptoms and insufficient sleep duration in early adolescents: associations with school stress.

Study Objectives: We examined how adolescents' sleep patterns (i.e. insomnia symptoms and sleep duration) change from early- to mid-adolescence and whether adolescents follow different trajectories. Furthermore, we also examined the characteristics of adolescents within different trajectories, with a specific focus on the role of school-related stress. Methods: We used three longitudinal waves of questionnaire data collected annually from a sample of Swedish adolescents (n = 1294; Mage = 13.2 [range: 12-15 years], SD = .42; 46.8% girls). Using established measures, the students reported on their sleep duration, insomnia symptoms, and perceived school-stress (including stress of school performance, peer and teacher relations, attendance, and school-leisure conflict). We used latent class growth analysis (LCGA) to identify adolescents' sleep trajectories, and the BCH method to describe the characteristics of the adolescents in each trajectory. Results: We found four trajectories for adolescents' insomnia symptoms; (1) low insomnia (69%), (2) low-increasing (17%, 'emerging risk-group'), (3) high-decreasing (9%), (4) high-increasing (5%; 'risk-group'). For sleep duration, we found two trajectories; (1) ~8 h sufficient-decreasing (85%), (2) ~7 h insufficient- decreasing (15%; 'risk-group'). Adolescents in risk-trajectories were more likely to be girls and consistently reported higher levels of school stress, particularly regarding school performance and attending school. Conclusions: School stress was prominent among adolescents suffering from persistent sleep problems, especially insomnia, and deserves further attention.

Insomnia symptoms and non-suicidal self-injury in adolescence: understanding temporal relations and mechanisms.

We propose a theoretical model of insomnia symptoms and non-suicidal self-injury (NSSI) that posits bidirectional linkages. We hypothesised that heightened depressive symptoms and impulsivity that result from insomnia increase NSSI. We also posit that the shame associated with NSSI triggers repetitive negative thinking, in turn increasing insomnia. Using three longitudinal waves of questionnaire data collected annually from a sample of Swedish adolescents (n = 1,457; Mage  = 13.2, SD = 0.43; 52.7% boys), we assessed the mediating role of depressive symptoms, impulsivity, rumination, and worry on the link between insomnia and NSSI. After controlling for depressive symptoms, we found that insomnia was related to increases in NSSI from the second to the third time point (ß23  = 0.09, p = .01). NSSI was consistently related to increased insomnia (ß12  = 0.09, p = .01; ß23  = 0.11, p < .001). In addition, depressive symptoms (ßind  = 0.01, p = .02), but not impulsivity (ßind  = 0.01, p = .09), mediated the path from insomnia to increased NSSI. Neither worry (ßind  = 0.00, p = .59) nor rumination (ßind  = 0.00, p = .96) mediated the link between NSSI and increased insomnia. We conclude that NSSI and insomnia maintain each other over time. Thus, screening adolescents for insomnia symptoms may help identify those at risk of NSSI. Although depression seems to explain why insomnia is a risk factor for NSSI, further studies should investigate why NSSI plays a role in the maintenance of insomnia. This understanding will lay the foundation for intervention.

Chronotype, circadian rhythms and mood.

Growing evidence shows a link between mood and chronotype. The majority of studies measure chronotype as a preference for morning/evening activities, rather than actual sleep behaviour (i.e. midsleep) or biological markers of sleep timing (e.g. dim light melatonin onset). Most studies show an association between chronotype and mood and identify eveningness as a potential risk for depression, but the directionality is unclear. Some evidence shows a stronger association between misalignment with the biological clock and depressive symptoms. This review provides a snapshot of recent research on chronotype and unipolar depression. We conclude that future studies should strive to integrate different measures of chronotype. This will give a clearer picture of the association between early/late chronotype and mood, which will in turn better inform clinical practice.

Preventing sleep deficit in adolescents: Long-term effects of a quasi-experimental school-based intervention study.

Adolescents are at risk of sleep deficit, which has serious consequences for their daytime functioning. However, school-based interventions to improve sleep have shown limited success. This might be due to the content of the programmes (e.g., not targeting central factors such as daytime stress and technology use) or because changes have not been captured due to a lack of long-term follow-ups. Hence, the aim of this study was to evaluate the long-term effects of a school-based sleep education curriculum including time-management training. The study used a quasi-experimental design. Participants were 3,622 adolescents (mean age 13.7, 48% girls); 286 were in the intervention group and 3,336 were followed as a natural control group. Data were collected before the intervention and at a 1-year follow-up. We divided participants into three groups according to baseline sleep duration (calculated from self-reported bed- and wake times, minus sleep onset latency): insufficient (<7 hr), borderline (7-8 hr) and adequate (>8 hr). Adolescents in the intervention group were ~2 times less likely to report insufficient sleep at follow-up as compared to controls. Sleep knowledge improved significantly in the intervention group but there were no changes in emotional sleep hygiene (e.g., bedtime worry) and perceived stress. Surprisingly, technology use increased and behavioural sleep hygiene worsened in the intervention group. Although the mechanisms of change need further investigation, the results of this study point to potential long-term benefits of school-based sleep programmes.

Bidirectional associations between adolescents' sleep problems and impulsive behavior over time.

OBJECTIVE/BACKGROUND: Adolescents who experience sleep problems are less able to resist impulses. Furthermore, youths who show more impulsive behaviors are, in turn, assumed to have more sleep problems, which sets the stage for a negative cycle over time. Empirical research has shown some evidence that sleep problems affect impulse control, but the bidirectional link has previously not been tested. Therefore, the aim of this study was to test this assumption. METHODS: In this study, we used cross-lagged models to investigate the bidirectional association between sleep problems (ie, insomnia and sleep duration) and impulsive behaviors over two years in a cohort of young adolescents (n = 2767, mean age ∼13.7, 47.6% girls). We also investigated the moderating role of age and gender. RESULTS: The results showed that the links between sleep duration/insomnia and impulsive behavior are bidirectional. Youths who experienced sleep problems also experienced increased difficulties with impulse control, and problems regulating impulses were also linked with increases in sleep problems, and these effects were systematic over two years. Moreover, age did not moderate these associations but impulsive behaviors had a larger impact on girls' insomnia as compared to boys. CONCLUSIONS: By confirming the bi-directionality of this association, this study supports the importance of developing interventions to promote sleep health in adolescents but also the need to tailor such programs to adolescents' development because adolescents might not be able to prioritize sleep if they cannot control their impulses.