Abnormal sleep-wake schedule or pattern associated with the CIRCADIAN RHYTHM which affect the length, timing, and/or rigidity of the sleep-wake cycle relative to the day-night cycle.
Abnormal sleep-wake schedule or pattern associated with the CIRCADIAN RHYTHM which affect the length, timing, and/or rigidity of the sleep-wake cycle relative to the day-night cycle.
Conditions characterized by disturbances of usual sleep patterns or behaviors. SLEEP WAKE DISORDERS may be divided into three major categories: DYSSOMNIAS (i.e. disorders characterized by insomnia or hypersomnia), PARASOMNIAS (abnormal sleep behaviors), and SLEEP WAKE DISORDERS secondary to medical or psychiatric disorders. (From Thorpy, Sleep Disorders Medicine, 1994, p187)