0202 Sleep Restriction Alters Time-Varying Attention in Adolescents: Moderation by Parent-Reported ADHD Traits

Introduction Adolescents are exposed to insufficient sleep due to bioregulatory and social pressures. Attention-deficit/hyperactivity disorder (ADHD) may increase vulnerability to the neurobehavioral consequences of this sleep loss. Traditional measures of attention (e.g., median reaction time [RT] from the Psychomotor Vigilance Task [PVT] do not capture temporal fluctuations in attention. Time-varying analysis of reaction time can better index moment-to-moment slowing or speeding. We tested whether sleep restriction changes the trajectory of PVT responses over time and whether ADHD traits moderate these effects. Methods Seventy-eight adolescents (range 10.1-15.7 [12.2±1.4] years; 42F) completed a 10-minute afternoon PVT after two counterbalanced 5-night at-home sleep conditions: sleep optimization (SO; 10h time-in-bed) and sleep restriction (SR; 7.5h time-in-bed). Youth were indexed for ADHD traits by parent-rated Conners-3 T-scores for inattention (range 40-90 [60.1±14.9]) and hyperactivity/impulsivity (range 40-90 [61.4±17.1]). We extracted each PVT response as a reciprocal reaction time (RRT=1/RT). Linear mixed models examined whether RT varied across time-on-task (i.e., elapsed time within the PVT), condition (SO vs. SR), and ADHD status (mean-centered Conners T-scores). Results We identified a series of effects. A significant interaction of time-on-task and condition (b=0.012, p=.017) indicated that after SO, RRT slowed across the task (b=-0.018, p=.12); however, after SR, RRT sped up over time (b=0.021, p=.017). This time-on-task-by-condition effect was moderated by both inattention (b=0.056, p=.001) and hyperactivity/impulsivity (b=0.058, p<.001) traits. In both cases, the effect of sleep condition on time-varying RRT was attenuated in youth with lower ADHD traits. Conclusion Sleep restriction altered adolescents’ time-varying attention, with responses increasing over time compared to a temporal slowing after sleep optimization. Youth with higher ADHD traits showed a stronger shift toward this speeded pattern, suggesting a distinct response phenotype under sleep loss. The consequences of these effects are not yet clear; however, they may reflect either a compensatory attention in youth with ADHD, or conversely, a shift towards impulsivity. Future analyses will link these data to other brain-behavioral outcomes to better understand these effects. Support (if any) R01HD103665 (JMS); P20GM139743 (MAC)