This the ﬁrst of two articles reviewing the scientiﬁc literature on the evaluation and treatment of circadian rhythm sleep disorders (CRS-Ds), employing the methodology of evidence-based medicine. In this ﬁrst part of this paper, the general principles of circadian biology that underlie clinical evaluation and treatment are reviewed. We then report on the ac-cumulated evidence regarding the evaluation and treatment of shift work disorder (SWD) and jet lag disorder (JLD).
A set of speciﬁc questions relevant to clinical practice were formulated, a systematic literature search was performed, and relevant articles were abstracted and graded.
A substantial body of literature has accumulated that provides a rational basis the evaluation and treatment of SWD and JLD. Physi-ological assessment has involved determination of circadian phase using core body temperature and the timing of melatonin secretion. Behavioral assessment has involved sleep logs, actigraphy and the Morningness-Eveningness Questionnaire (MEQ). Treatment interventions fall into three broad categories: 1) prescribed sleep scheduling, 2) circadian phase shift-ing (“resetting the clock”), and 3) symptomatic treatment using hypnotic and stimulant medications.
Circadian rhythm science has also pointed the way to ratio-nal interventions for the SWD and JLD, and these treatments have been introduced into the practice of sleep medicine with varying degrees of success. More translational research is needed using subjects who meet current diagnostic criteria.