[2019] Lee HJ. Circadian Misalignment and Bipolar Disorder. Chronobiol Med. 2019;1(4):132-136. Published online December 31, 2019. DOI: https://doi.org/10.33069/cim.2019.0027

The circadian rhythm is a periodic and continuous change caused by the light/dark cycle as the Earth rotates around its own axis in a 24- hour cycle. The circadian clock system regulates the 24-hour daily rhythms of human physiology and behavior such as the sleep/wake cycle, body temperature, hormone secretion, and mood. The influence of circadian rhythm on the body and mind is obvious, but considerable research has not dealt with its effects on human disease, especially on mental illnesses. However, several recent studies have shown that circadian misalignment may play an important role in the pathogenesis of bipolar disorder. Evidence for circadian rhythm misalignment in bipolar disorder suggests that circadian rhythm phase shift is a key pathophysiologic mechanism.