Bipolar disorder is characterised by repeated episodes of significantly disturbed mood and activity levels. Even with appropriate pharmacological and psychological management, the occurrence of relapse in patients with bipolar disorder is high. The underlying mechanisms that lead to relapse in bipolar disorder are not known, and represent an important area of investigation for the development of additional management strategies and interventions to reduce the rate of relapse in these patients. Both circadian disruption and sleep-wake disturbance have been widely reported to occur in bipolar disorder, in all phases. Despite this, few studies have carefully evaluated alterations in these systems, nor the role that these two systems may play in the occurrence of subsequent relapses.

Assessment of circadian rhythms and sleep-wake behaviour in patients with bipolar disorder may provide important information regarding progression of symptoms, and provide an early marker of transitions between phases in bipolar disorder. Long term assessment of circadian and sleep-wake timing can be achieved using ambulatory monitoring of sleep-wake behaviour, using actigraphy and sleep diaries. These assessments would be an important clinical tool in the ongoing management of bipolar disorder. Combining pharmacological and/or behavioural treatments for BPD with treatments to manage circadian and sleep-wake disturbance may represent a new management strategy for bipolar disorder, and ultimately reduce the incidence of relapse in many patients.