Sleep duration and mood in adolescents: an experimental study.

STUDY OBJECTIVES

This study examines the relationship between experimentally manipulated sleep duration and mood in adolescents.

METHODS

Thirty-four adolescents (20 male), aged 15-17 years, lived in a sleep laboratory for 10 days and 9 nights. They were allocated to one of three sleep "doses" for five consecutive nights for 5, 7.5, or 10 h sleep opportunity per night. Two baseline nights and two recovery nights entailed 10 h sleep opportunity per night. Mood was measured every 3 h during wake using unipolar visual analogue scales measuring the mood states "depressed," "afraid," "angry," "confused," "anxious," "happy," and "energetic."

RESULTS

Mixed models analyses with post hoc comparisons revealed that participants in the 5-h group, but not the 7.5- or 10-h groups, reported being significantly more depressed, angry, and confused during sleep restriction than at baseline. Adolescents were significantly less happy and energetic during sleep restricted to 5 h and significantly less energetic during sleep restricted to 7.5 h. When adolescents had 10 h sleep opportunities their happiness significantly increased. No statistically significant effects of sleep restriction were found for fear or anxiety, although small-to-moderate effects of sleep restricted to 5 or 7.5 h were found. Two nights of recovery sleep was not sufficient to recover from increased negative mood states for the 5-h group, although recovery occurred for positive mood states.

CONCLUSIONS

Given the prevalence of insufficient sleep and the rising incidence of mood disorders and dysregulation in adolescents, these findings highlight the importance of sufficient sleep to mitigate these risks.