The Implications of Chronobiology for Psychiatry

Chronobiology—the science of daily (circadian), monthly, tidal, and seasonal rhythms—has undergone exponential growth in the past decade, with major discoveries at the molecular and neuroanatomic level. The most ubiquitous rhythms are those linked to the 24-hour day-night cycle. These circadian rhythms manifest themselves at every hierarchical level: from the general population (eg, more traffic accidents late at night) to the individual (eg, the sleep-wake cycle), in each organ, cell, and molecule. Rhythmic change provides the temporal organization necessary for optimum behavior—the right function at the right time.