Irregular sleep-wake rhythm disorder

**Definition:** Irregular sleep-wake rhythm disorder is characterised by absence of a clearly-defined cycle of sleep and wake. Sleep becomes distributed in multiple episodes of variable duration throughout the 24-hour period. Patients typically complain of insomnia and/or excessive daytime sleepiness as a result of the condition. The symptoms should have persisted for at least several months and result in significant distress or mental, physical, social, occupational or academic impairment.

**Inclusions:** - irregular sleep-wake pattern