BackgroundThe relationship between inadequate sleep and mood has been well-established in adults and is supported primarily by correlational data in younger populations. Given that adolescents often experience shortened sleep on school nights, we sought to better understand the effect of experimentally induced chronic sleep restriction on adolescents' mood and mood regulation. MethodsFifty healthy adolescents, ages 14-17, completed a 3-week sleep manipulation protocol involving a baseline week, followed by a sleep restriction (SR) condition (6.5hr in bed per night for five nights) and healthy sleep duration (HS) condition (10hr in bed per night for five nights). The study used a randomized, counterbalanced, crossover experimental design. Participants' sleep was monitored at home via self-report and actigraphy. At the end of each condition, participants and their parents completed questionnaires of mood and mood regulation. To assess for expectancy effects, we also analyzed parent and teen ratings of hyperactivity/impulsivity, which prior research suggests is not sensitive to SR in adolescents. Wilcoxon Signed Rank tests compared questionnaire outcomes across the two conditions. ResultsParticipants averaged 2.5 more hours of sleep per night during HS relative to SR. Compared with HS, adolescents rated themselves as significantly more tense/anxious, angry/hostile, confused, and fatigued, and as less vigorous (p=.001-.01) during SR. Parents and adolescents also reported greater oppositionality/irritability and poorer emotional regulation during SR compared with HS (p.05). ConclusionsFindings complement prior correlational study results to show that after only a few days of shortened sleep, at a level of severity that is experienced regularly by millions of adolescents on school nights, adolescents have worsened mood and decreased ability to regulate negative emotions.