P.1.a.005 Lithium-induced changes in circadian gene expression in lymphoblastoid cell lines of bipolar patients

Technology-related behaviors (e.g., computer use) before bedtime (BT) have been associated with poorer and shorter sleep in adolescents; however, less is known about other behaviors in relation to sleep. This study characterized a range of behaviors in the hour before bed (i.e., pre-BT behaviors [PBBs]) and examined their relationship with sleep parameters during school and vacation periods (i.e., restricted and extended sleep opportunities, respectively). Mechanistic roles of chronotype and cognitive presleep arousal (PSAcog) were also examined.During the last week of a school term and throughout a 2-week vacation, 146 adolescents (47.26% male, age M ± standard deviation = 16.2 ± 1.0 years) from the general community completed daily sleep measure using actigraphy, self-report measures on PBBs and PSAcog (Presleep Arousal Scale) for both school and vacation periods, and chronotype (Morningness–Eveningness Questionnaire).Adolescents engaged in a variety of behaviors before bed. Notably, playing video games was associated with significantly later school and vacation BT and shorter school sleep duration (controlling for chronotype). During vacation, online social media was associated with significantly longer sleep onset latency, and this relationship was mediated by higher PSAcog. In contrast, on school nights, spending time with family was associated with significantly earlier BT and longer sleep duration.Technology-related PBBs video games and online social media were risk factors for shorter and poorer sleep, whereas time with family was protective of sleep duration. In addressing sleep problems in adolescents, therapeutic procedures that target the potentially addictive nature of technology use and reduce PSAcog were implicated.