An MJA editorial on circadian rhythms published nearly 40 years ago lamented the “neglect ... in part engendered by the air of mysticism which surrounded much of the earlier work in this field” that had obscured recognition of their importance to health.1 Since that time, basic research has explored various aspects, including the intracellular generation of circadian oscillations, their intercellular synchronisation, the entrainment of the circadian “system” by environmental time cues or “zeitgebers” such as light, and circadian variation in biological functioning. Further, clinical research has focused on the consequences of circadian disruption, circadian rhythm sleep disorders (CRSDs), circadian abnormalities in affective disorders, and chronotherapy. Here, we summarise some of these key advances.

©The Medical Journal of Australia 2009 www.mja.com.au PRINT ISSN: 0025-729X ONLINE ISSN: 1326-5377