The relationship between bipolar disorder and biological rhythms.

BACKGROUND: Rhythm disruption is a core feature of bipolar disorder and it has been hypothesized that disturbances of the circadian timing system play a fundamental role in the etiology of the disorder.
OBJECTIVE: We sought to investigate (1) theoretical models for biological rhythm disruptions in bipolar disorder, (2) physiological disturbances of biological rhythms in bipolar disorder, (3) clinical and therapeutic implications of biological rhythm disturbances in bipolar disorder, and (4) associations between circadian gene variations and bipolar disorder. DATA SOURCES: PubMed database was searched systematically for articles that were published on or before May 5, 2013, and were written in English using the terms bipolar disorder, clock genes, endogenous clock, molecular clock, biological rhythms, circadian, suprachiasmatic nucleus, circadian rhythm, melatonin, and sleep. STUDY SELECTION: Seventy-four articles highlighting the objectives were included in the review. DATA EXTRACTION: Data regarding exploring the association between bipolar disorder and circadian and chronobiological phenomena were reviewed and findings summarized.
RESULTS: The literature reviewed suggests that circadian rhythm disturbance may be a feature of bipolar disorder.
CONCLUSIONS: In toto, the literature suggests that circadian rhythm disturbances may be a feature of bipolar disorder. This area of research has received theoretical consideration as playing a significant role in the pathophysiology of the illness but has been understudied to this point. Further research in the field is warranted. © Copyright 2014 Physicians Postgraduate Press, Inc.