The article you requested is

Sleep and Circadian Rhythm Disturbances in Bipolar Disorder: An Urgent Need for Objective Assessment and Systematic Follow-Up

J Clin Psychiatry 2011;72(5):724 [letter]

Letter to the Editor

Because this piece does not have an abstract, we have provided for your benefit the first 3 sentences of the full text.

We read with great interest the recent article from Leboyer and Kupfer, which proposes a new framework for bipolar disorder as a chronic and progressive multisystem disorder associated with significant emotional disturbance and cognitive impairment between episodes. That article also highlights as an unmet need the lack of systematic follow-up in some of the core dimensions of bipolar disorder such as sleep and circadian rhythm. In this regard, we have recently developed and validated an instrument to assess biological rhythm in individuals with bipolar disorder.