Weekend-weekday advances in sleep timing are associated with altered reward-related brain function in healthy adolescents.

Sleep timing shifts later during adolescence, thus conflicting with early school start times. This can lead to irregular weekday-weekend schedules and circadian misalignment, which have been linked to depression and substance abuse, consistent with disruptions in the processing of rewards. We tested associations between weekend-weekday shifts in sleep timing and the neural response to monetary reward in healthy adolescents, using actigraphy and a functional magnetic resonance imaging paradigm. Region-of-interest analyses focused on the medial prefrontal cortex (mPFC) and striatum, both of which are implicated in reward function. Analyses adjusted for pubertal stage, sex, and total sleep time. Greater weekend-weekday advances in midsleep were associated with decreased mPFC and striatal reactivity to reward, which could reflect reduced regulatory response and reward sensitivity. We speculate that circadian misalignment associated with weekend shifts in sleep timing may contribute to reward-related problems such as depression and substance abuse.