The focus of this article is to review several commonly used methods for the assessment of
circadian rhythms as it relates to circadian rhythm sleep-wake disorders (CRSWDs). 1 It also
touches on recent research on the development of new biomarkers of the circadian system
in humans. The goal of this article is not to provide specific details of the methods to assess
circadian rhythms; rather, it is to review the key factors to consider when selecting a method
and when collecting and interpreting the data from these measures. Reference to works that …