A meta-analysis and model of the relationship between sleep and depression in adolescents: recommendations for future research and clinical practice.

The purpose of this review was to quantify the strength of evidence for a directional relationship between sleep disturbance and depression in adolescents. A literature search was conducted to identify research investigating the relationship between sleep disturbance and depression in adolescent samples (12-20 y). Twenty-three studies were identified; 13 explored associations between depression and sleep disturbance; seven examined the prospective role of sleep disturbance in the development of depression; and three investigated the role of adolescent depression in the development of subsequent sleep disturbance. Average weighted mean differences in sleep/depression-related outcome variables were calculated between adolescents with depression, and non-clinical adolescents, or those in remission. Adolescents with depression experienced significantly more wakefulness in bed (sleep onset latency, wake after sleep onset, number of awakenings and sleep efficiency), lighter sleep (more stage 1), and reported more subjective sleep disturbance. Overall effect sizes from longitudinal and treatment studies suggest sleep disturbance acts as a precursor to the development of depression. At follow-up, depressed adolescents had significantly longer sleep onset, more wake after sleep onset, and lower sleep efficiency compared to adolescents who were non-clinical, or had undergone remission. Little support was found for a predictive role of depressive symptoms in the development of sleep disturbance. Based on these findings we propose a model to understand the development of depression from initial sleep disturbance, provide recommendations for clinicians and recommendations for future research.