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Depression Research and Treatment
Volume 2011 (2011), Article ID 839743, 9 pages
http://dx.doi.org/10.1155/2011/839743
Review Article

Disruption of Circadian Rhythms: A Crucial Factor in the Etiology of Depression

1Departamento de Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, 04306 México, DF, Mexico
2Departamento de Anatomía, Facultad de Medicina, Universidad Nacional Autónoma de México, 04306 México, DF, Mexico

Received 31 January 2011; Revised 4 May 2011; Accepted 6 June 2011

Academic Editor: Dietrich van Calker

Copyright © 2011 Roberto Salgado-Delgado et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Circadian factors might play a crucial role in the etiology of depression. It has been demonstrated that the disruption of circadian rhythms by lighting conditions and lifestyle predisposes individuals to a wide range of mood disorders, including impulsivity, mania and depression. Also, associated with depression, there is the impairment of circadian rhythmicity of behavioral, endocrine, and metabolic functions. Inspite of this close relationship between both processes, the complex relationship between the biological clock and the incidence of depressive symptoms is far from being understood. The efficiency and the timing of treatments based on chronotherapy (e.g., light treatment, sleep deprivation, and scheduled medication) indicate that the circadian system is an essential target in the therapy of depression. The aim of the present review is to analyze the biological and clinical data that link depression with the disruption of circadian rhythms, emphasizing the contribution of circadian desynchrony. Therefore, we examine the conditions that may lead to circadian disruption of physiology and behavior as described in depressive states, and, according to this approach, we discuss therapeutic strategies aimed at treating the circadian system and depression.