0247 How Do Types of Digital Content and Motives for Nighttime Device Use Relate to Sleep and Mental Health Among Adolescents?

Abstract Introduction Nighttime device use is associated with sleep problems. Studies have focused on the quantitative aspects of device use (e.g., duration, frequency) but not the qualitative aspects. This study examined how nighttime device use among adolescents relates to sleep and mental health, focusing on the following qualitative aspects: (A) digital content types and (B) motives for use. Methods Participants (n=831, aged 12–18 years) reported their sleep habits, frequency of smartphone use in bed, pre-bedtime activities (e.g., videos, gaming), and answered the Pediatric Daytime Sleepiness Scale (PDSS) and the Generalized Anxiety Disorder-7 (GAD-7). Participants who used smartphones in bed reported six use motives (e.g., habitual use, distraction) and duration of use. Hierarchical cluster analyses were based on (A) pre-bedtime activities and (B) motives for smartphone use in bed. Associations between activity-based clusters and sleep habits, PDSS, and GAD-7 were examined using ANCOVA adjusted for gender. Associations between motive-based clusters and the same outcomes were analyzed using multivariable logistic regression adjusted for grade, gender, and duration of smartphone use in bed. Results (A) Based on pre-bedtime activity responses (n=831), five clusters were identified: Cluster 1, “passive media users” (n=287); Cluster 2, “studying & passive media users” (n=88); Cluster 3, “heavy social networking services (SNS) users” (n=61); Cluster 4, “heavy gaming users” (n=84); and Cluster 5, “lower device users” (n=311). “Lower device users” showed advanced sleep–wake phase and longer weekday sleep duration than the other clusters. “Studying & passive media users” and “heavy SNS users” showed stronger sleepiness and anxiety. (B) Based on smartphone-use motive responses (n=506), four clusters were identified: Cluster A, “diverse users” (n=152); Cluster B, “diverse users excluding distraction” (n=139); Cluster C, “habitual users” (n=127); Cluster D, “purposeful users” (n=88). Compared with “purposeful users,” social jetlag was more likely among “diverse users” (aOR=2.35*), “diverse users excluding distraction” (aOR=2.27*), and “habitual users” (aOR=2.99**). Furthermore, “diverse users” had higher odds for sleepiness (aOR=2.54**) and anxiety (aOR=3.25***). Conclusion This study showed differences in digital content and motives for smartphone use to be associated with sleep habits, daytime sleepiness, and anxiety. These findings highlight the need to consider both quantitative and qualitative aspects of device use. Support (if any)