Sleep and sleep treatments in bipolar disorder.

Sleep and circadian disturbances in bipolar disorder are common and persistent within and between illness episodes. Insomnia, hypersomnia, reduced need for sleep, sleep schedule variability and circadian rhythm disorders are frequently observed. In this article, recent research is reviewed suggesting that the presence of sleep disturbance is associated with functional impairment, interacts with other physical and environmental systems (e.g. physical activity, light exposure), and may attenuate response to treatment. Established and emerging treatments for various sleep disturbances are reviewed, with emphasis on applications for light therapy and adapted cognitive behavioral therapy. There remains a critical need to understand the co-occurrence of various sleep disturbances, develop, and refine treatment approaches (especially for hypersomnia/long sleep duration) and adapt wearable and smartphone technologies to aid assessment and intervention.