Circadian genes, rhythms and the biology of mood disorders

Pharmacol Ther. 2007 May;114(2):222-32. doi: 10.1016/j.pharmthera.2007.02.003. Epub 2007 Feb 28.


For many years, researchers have suggested that abnormalities in circadian rhythms may underlie the development of mood disorders such as bipolar disorder (BPD), major depression and seasonal affective disorder (SAD). Furthermore, some of the treatments that are currently employed to treat mood disorders are thought to act by shifting or "resetting" the circadian clock, including total sleep deprivation (TSD) and bright light therapy. There is also reason to suspect that many of the mood stabilizers and antidepressants used to treat these disorders may derive at least some of their therapeutic efficacy by affecting the circadian clock. Recent genetic, molecular and behavioral studies implicate individual genes that make up the clock in mood regulation. As well, important functions of these genes in brain regions and neurotransmitter systems associated with mood regulation are becoming apparent. In this review, the evidence linking circadian rhythms and mood disorders, and what is known about the underlying biology of this association, is presented.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Biological Clocks / genetics*
  • Bipolar Disorder / genetics
  • Bipolar Disorder / physiopathology
  • Circadian Rhythm / genetics*
  • Depressive Disorder, Major / genetics
  • Depressive Disorder, Major / physiopathology
  • Gene Expression
  • Genes / physiology
  • Humans
  • Mood Disorders* / genetics
  • Mood Disorders* / physiopathology
  • Mood Disorders* / therapy
  • Phototherapy
  • Seasonal Affective Disorder / genetics
  • Seasonal Affective Disorder / physiopathology
  • Sleep Deprivation