Impact of Social Media Use on Adolescent Sleep Quality and Mood Regulation

Thesis Abstract

The rapid proliferation of social media use among adolescents coincides with growing concerns about its impact on sleep health and mood regulation, presenting a key public health issue given links between sleep disruption and psychiatric symptoms in youth. This study aims to examine the extent to which daily social media engagement, content type, and usage timing predict sleep quality and mood regulation in adolescents, with a focus on identifying mediating and moderating factors such as pre-sleep arousal, blue-light exposure, perceived social support, and individual differences in Rumination and Delay of Gratification. The specific objectives are (1) to quantify associations between duration and timing of social media use and objectively measured sleep parameters (sleep onset latency, total sleep time) alongside subjective sleep quality; (2) to assess relationships between social media habits and mood regulation indicators (emotional lability, coping efficacy, rumination) using validated scales; (3) to test a mediation model in which pre-sleep arousal and blue-light exposure mediate the effect of evening social media use on sleep quality; (4) to evaluate moderation by sex, age, and baseline depressive symptoms; and (5) to compare predictive power of content type (interactive versus passive consumption) on both sleep and mood outcomes. A mixed-methods approach will be employed in a longitudinal, school-based cohort study. The population comprises adolescents aged 13–17 years from three urban secondary schools. A stratified random sample of 600 students will be recruited, with data collected at baseline, 3 months, and 6 months. Quantitative data will be gathered using (i) actigraphy-based sleep measures (SleepWatch wrist accelerometers) for objective sleep metrics, (ii) self-report instruments including the Pittsburgh Sleep Quality Index, Parent/Student Depression Scales for depressive symptoms, the Difficulties in Emotion Regulation Scale, the Rumination Response Scale, and the Social Media Use Integration Scale, and (iii) an Ecological Momentary Assessment (EMA) protocol administered via smartphones to capture real-time social media activity, perceived arousal, and pre-sleep behaviors over two-week windows at each wave. Blue-light exposure will be estimated from device usage logs and self-reported screen brightness settings. The qualitative component will involve semi-structured interviews with a purposive subsample of 30 participants to elucidate perceived mechanisms linking social media use, sleep, and mood. Quantitative data will be analyzed using multilevel structural equation modeling to test the hypothesized mediation and moderation effects, controlling for baseline sleep difficulties, socioeconomic status, and extracurricular activity. Regression analyses will identify unique contributions of total usage time, late-evening use (after 9 p.m.), and content type to sleep quality and mood regulation outcomes. Thematic analysis will be applied to interview transcripts to extract nuanced themes regarding cognitive and emotional processes, which will be integrated with quantitative findings through a mixed-methods synthesis. The study anticipates that evening social media use—particularly passive scrolling and exposure to distressing content—will be significantly associated with poorer sleep quality (higher sleep onset latency, reduced total sleep time) and weaker mood regulation, with pre-sleep arousal and blue-light exposure partly mediating these relationships; moderators may include sex and baseline depressive symptoms. The expected contribution to knowledge includes clarifying causal pathways linking social media engagement to adolescent sleep and affective regulation, identifying actionable targets for intervention (e.g., sleep hygiene education, digital curfews, content-type awareness), and informing school- and family-based prevention programs. The study will advance theoretical development by integrating the cognitive arousal framework with neurobiological considerations of light exposure and emotion regulation models, such as the Process Model of Emotion Regulation and the Capacities for Self-Regulation framework. Practical implications involve evidence-based guidelines for parents, educators, and policymakers regarding adolescent social media policies, screen-time recommendations, and mental health screening in school settings. The main conclusion is expected to emphasize the significance of timing and content of social media use for sleep health and mood regulation, advocating a multimodal approach to mitigation that combines behavioral strategies, psychoeducation, and, where appropriate, digital literacy interventions. Recommendations will include targeted sleep hygiene interventions in schools, development of adolescent-friendly digital well-being curricula, and further longitudinal research across diverse populations to examine long-term outcomes.