There is increasing interest in the connection between sleep disturbances and mood disorders. The purpose of this review is to summarize and evaluate current research on the role of sleep disturbance in the development of depression, as well as to describe recent advances in treatments that improve both sleep and depression symptoms.

Relevant publications included in this review cover a wide range of topics related to sleep and depression. Data from large longitudinal studies suggest that insomnia and evening circadian preference are unique risk factors for depression. Depression treatment studies indicate poorer outcomes for those with comorbid sleep disturbances. A few recent trials of cognitive behavioral therapy for insomnia and triple chronotherapy in unipolar depression have shown promising results.

Sleep disturbance is a modifiable risk factor in the development and maintenance of depression. In the context of current depression, although the data is mixed, some evidence suggests treating sleep disturbance can improve overall outcomes. Recent evidence also suggests that treating sleep disturbance may prevent the future depressive episodes.