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

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

To the Editor: We read with great interest the recent article from Leboyer and Kupfer,1 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.1 In this regard, we have recently developed and validated an instrument to assess biological rhythm in individuals with bipolar disorder.2 The Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN) is a semistructured scale divided into 4 domains (sleep, activities, social rhythm, and eating pattern) and is able to discriminate between euthymic bipolar subjects and healthy controls in all 4 domains.2 In addition, the BRIAN scale showed an excellent test-retest agreement (0.98), was highly correlated with the Pittsburgh Sleep Quality Index (PSQI) scores (r = 0.77; P < .001), and was an independent predictor of functioning in euthymic bipolar patients (β = 14.3; P < .001).2,3

Disturbances in sleep pattern have been considered the strongest predictors of manic relapse in bipolar disorder.4 Considering the cumulative body of research showing the negative impact of sleep disturbance in declarative memory5 and in biological markers of allostatic load,6 the use of objective measures of circadian rhythm can help to improve the understanding of the crosslink between abnormalities in sleep and circadian rhythm, cognitive impairment, inflammation, and oxidative stress6,7 and to assess the impact of pharmacologic and psychosocial interventions in the treatment of bipolar disorder. Ultimately, as suggested by Leboyer and Kupfer,1 a reexamination of the traditional view of bipolar disorder from an episodic illness to a chronic, multisystemic disorder can impact health care policies and services and improve preventive strategies for this devastating illness.

References

1. Leboyer M, Kupfer DJ. Bipolar disorder: new perspectives in health care and prevention. J Clin Psychiatry. 2010;71(12):1689-1695. PubMed doi:10.4088/JCP.10m06347yel

2. Giglio LM, Magalhães PV, Andreazza AC, et al. Development and use of a biological rhythm interview. J Affect Disord. 2009;118(1-3):161-165. PubMed doi:10.1016/j.jad.2009.01.018

3. Giglio LM, Magalhães PV, Kapczinski NS, et al. Functional impact of biological rhythm disturbance in bipolar disorder. J Psychiatr Res. 2010;44(4):220-223. PubMed doi:10.1016/j.jpsychires.2009.08.003

4. Jackson A, Cavanagh J, Scott J. A systematic review of manic and depressive prodromes. J Affect Disord. 2003;74(3):209-217. PubMed doi:10.1016/S0165-0327(02)00266-5

5. Gais S, Born J. Declarative memory consolidation: mechanisms acting during human sleep. Learn Mem. 2004;11(6):679-685. PubMed doi:10.1101/lm.80504

6. McEwen BS. Sleep deprivation as a neurobiologic and physiologic stressor: allostasis and allostatic load. Metabolism. 2006;55(suppl 2):S20-S23. PubMed doi:10.1016/j.metabol.2006.07.008

7. Kapczinski F, Vieta E, Andreazza AC, et al. Allostatic load in bipolar disorder: implications for pathophysiology and treatment. Neurosci Biobehav Rev. 2008;32(4):675-692. PubMed doi:10.1016/j.neubiorev.2007.10.005

Flavio Kapczinski, MD, PhD

Benicio N. Frey, MD, PhD

Eduard Vieta, MD, PhD

evieta@clinic.ub.es

Dr Leboyer was shown this letter and declined to comment.

Author affiliations: Bipolar Disorders Program & INCT for Translational Medicine, Hospital de Clí­nicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil (Dr Kapczinski); Mood Disorders Program and Women’s Health Concerns Clinic, Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada (Dr Frey); and Bipolar Disorders Program, Institute of Neuroscience, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Catalonia, Spain (Dr Vieta). Potential conflicts of interest: None reported. Funding/support: None reported.

doi:10.4088/JCP.11l06850

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