An investigation of the longitudinal relationship between sleep and depressed mood in developing teens.

OBJECTIVE: The prospective, bidirectional relationship between sleep disturbance and depressed mood was assessed in a school-based sample of adolescents.

METHOD: One hundred and thirty-eight Australian adolescents (mean age time 1 =15.69, standard deviation =0.92; 64% male) completed questionnaires to assess sleep parameters and depressed mood, on two occasions over 1 year.

RESULTS: Cross-sectional associations were observed between depressed mood and sleep duration, as well as wakefulness in bed. Prospective analyses revealed depressed mood predicted less total sleep time on school nights and a longer latency to sleep onset on weekends 1 year later. There was no prospective support for sleep predicting later depressed mood.

CONCLUSION: Contrary to prediction, our results suggest in this case that depressed mood may act as a precursor to poor sleep rather than the converse.