Associations Between Multiple Dimensions of Sleep and Mood During Early Adolescence: A Longitudinal Daily Diary Study

Adolescents' screen time displaces multiple sleep pathways and elevates depressive symptoms over twelve months

Recently the Swedish Public Health Agency published recommendations of a maximum of two-to-three hours of daily leisure screen time for adolescents aged 13-18, partly to promote better sleep (2024-Sep-02). Biologically and socially, adolescence is characterized by belated sleep times, and depressive effects of screen time can arise through sleep displacements. Theorized links between screen time, sleep, and depression, merited examination of four sleep mediators to determine their relative importance and determine which of them mediate future depression. Hypotheses were preregistered. Three-wave psychometric health data were collected from healthy Swedish students (N = 4810; 51% Boys; ages 12-16; N = 55 schools; n = 20 of 26 Stockholm municipalities). Multiple imputation bias-corrected missing data. Gender-wise Structural Equation Modelling tested four sleep facets as competing mediators (quality, duration, chronotype, social jetlag). The primary model result included the three first mediators to achieve acceptable fit indices (RMSEA = 0.02; SRMR = 0.03; CFI = 0.95; TLI = 0.94). Screen time deteriorated sleep within three months and effect sizes varied between mediators (Beta weights ranged: 0.14-0.30) but less between genders. Among boys, screen time at baseline had a direct adverse effect on depression after twelve months (Beta = 0.02; p <0.038). Among girls, the depressive effect was mediated through sleep quality, duration, and chronotype (57, 38, 45% mediation). Social jetlag remained non-significant. This study supports a modernized 'screen-sleep-displacement theory'. It empirically demonstrates that screen-sleep displacements impact several aspects of sleep simultaneously. Displacements led to elevated depressive symptoms among girls but not boys. Boys may be more prone to externalizing symptoms due to sleep loss. Results could mirror potentially beneficial public health effects of national screen time recommendations.

Exploring the association between sleep problems and loneliness in adolescents: Potential mediating effects of rumination and resilience

Sleep problems positively predict loneliness to a large extent, which would harm adolescent health. However, little is known about the underlying mechanism. This research investigates the potential mediating roles of rumination and resilience in the relation among adolescents and further examines the changing relationships. In Study 1, 1056 adolescents from two schools completed self-reported measures of sleep problems, loneliness, rumination, and resilience. We found that sleep problems were positively associated with loneliness, and that rumination and resilience mediated this relationship, both individually and sequentially. To examine the varying relationship between rumination, resilience, and loneliness, Study 2 adopted the cross-lagged design in a long-term longitudinal study of 131 students and found that rumination and resilience at T1 significantly predict loneliness at T2. To further directly explore the changing relationship between sleep problems and loneliness, we performed a short-term longitudinal study across 7 weeks of 242 adolescents in Study 3. The results replicated the findings of Study 2 and found sleep problems at T1 positively predicted loneliness at T2. These results underscore the significance of sleep problems in contributing to loneliness through mediating mechanisms and unveil the possible causal relationships, offering robust insights to alleviate adolescent loneliness.

Linking Daily Victimization to Daily Affect Among Adolescents: The Mediating Role of Sleep Quality and Disturbance

Bullying victimization is prevalent among adolescents and often linked to emotional problems. Prior studies have been focused on the concurrent or longitudinal associations between bullying victimization and emotional problems, but the daily associations and the underlying mechanisms remain unclear. Implementing daily diary method, the study aimed to examine the links between daily victimization and positive and negative affect as well as the mediating role of sleep quality and disturbance. A total of 265 Chinese adolescents (Mage = 11.65, SD = 0.74; 32.80% females) participated in this study and completed 7-day daily diaries on bullying victimization (traditional and cyber victimization), sleep quality and disturbance, and affect. As hypothesized, at the between-person level, sleep disturbance mediated the relationships between both traditional and cyber victimization and subsequent negative affect. At the within-person level, sleep quality mediated the pathway between traditional victimization and next-day negative affect; furthermore, sleep disturbance mediated the pathway between traditional victimization and positive affect the following day. These findings highlight the mediating roles of sleep quality and sleep disturbance in the relationships between stressful victimizing experiences and emotional problems and also provide novel insights into these associations.

Monitoring Daily Sleep, Mood, and Affect Using Digital Technologies and Wearables: A Systematic Review

Background: Sleep and affective states are closely intertwined. Nevertheless, previous methods to evaluate sleep-affect associations have been limited by poor ecological validity, with a few studies examining temporal or dynamic interactions in naturalistic settings. Objectives: First, to update and integrate evidence from studies investigating the reciprocal relationship between daily sleep and affective phenomena (mood, affect, and emotions) through ambulatory and prospective monitoring. Second, to evaluate differential patterns based on age, affective disorder diagnosis (bipolar, depression, and anxiety), and shift work patterns on day-to-day sleep-emotion dyads. Third, to summarise the use of wearables, actigraphy, and digital tools in assessing longitudinal sleep-affect associations. Method: A comprehensive PRISMA-compliant systematic review was conducted through the EMBASE, Ovid MEDLINE(R), PsycINFO, and Scopus databases. Results: Of the 3024 records screened, 121 studies were included. Bidirectionality of sleep-affect associations was found (in general) across affective disorders (bipolar, depression, and anxiety), shift workers, and healthy participants representing a range of age groups. However, findings were influenced by the sleep indices and affective dimensions operationalised, sampling resolution, time of day effects, and diagnostic status. Conclusions: Sleep disturbances, especially poorer sleep quality and truncated sleep duration, were consistently found to influence positive and negative affective experiences. Sleep was more often a stronger predictor of subsequent daytime affect than vice versa. The strength and magnitude of sleep-affect associations were more robust for subjective (self-reported) sleep parameters compared to objective (actigraphic) sleep parameters.

Associations between capacity of cognitive control and sleep quality: a two-wave longitudinal study

This longitudinal study explored the impact of the upper limit of cognitive control on the sleep quality of high school students. We collected data in two waves to examine four main variables: capacity of cognitive control (CCC), trait mindfulness, emotional distress and sleep quality. At the first time point (T1), trait mindfulness and emotional distress were measured by rating scales, and the CCC was evaluated by revised backward masking majority function task. Sleep quality was rated 5 months later (T2). The results indicated that: (1) the CCC was negatively correlated with trait mindfulness, and trait mindfulness was negatively correlated with emotional stress; (2) there was no simple mediation of either trait mindfulness or emotional distress in the relationship between CCC and sleep quality; (3) instead, the CCC was associated with poor sleep quality in a sequential mediation through trait mindfulness and then emotional stress. The research highlights the importance of trait mindfulness and emotional distress for addressing sleep problems in adolescents.