Circadian rhythm sleep disorders

Circadian rhythm sleep disorders, according to the ICSD-2, comprise a list of complaints sharing a common pathophysiological basis of misalignment between internal circadian rhythms and the desired or required time for sleep. The sleep disturbance produces sleep and wake periods that occur at inappropriate times, resulting in a complaint of insomnia or excessive sleepiness for patients. Diagnostic criteria include social or occupational impairment, and a diagnosis of CRSDs is appropriate only in the absence of other primary sleep disorders. The CRSDs recognized by ICSD-2 are: 1) Delayed sleep phase syndrome; 2) Advanced sleep-phase syndrome; 3) Non-24 hours sleepwake syndrome; 4) Jet lag syndrome; 5) Shift work disorder; 6) Irregular sleep-wake pattern; 7) Circadian rhythm sleep disorder due to medical condition; 8) Circadian rhythm sleep disorder due to drug or substance; 9) Circadian rhythm sleep disorder, not otherwise specified.