Circadian Rhythm Sleep Disorders

Sleep disorders

disturbances to typical sleeping and waking patterns

Circadian rhythm sleep disorders

sleep disorders that interfere with the typical regulation of the circadian rhythm of sleep, leading to a change in the sleep-wake cycle

Delayed Sleep Phase Syndrome (DSPS)

a type of circadian rhythm sleep disorder in which sleep and waking occur later than usual (usually 1-2 hours)

cause of DSPS

DSPS is caused by a misalignment between internal and external cues that regulate the circadian rhythm.

• individual still receives external cues of light in morning and dark at night

• do not receive internal cues properly

• causes melatonin secretion to occur later and therefore the individuals sleep and wake cycles are also later

Advanced sleep phase disorder (ASPD)

a type of circadian rhythm sleep disorder in which sleep and waking occur earlier than usual

cause of ASPD

ASPD is caused by a misalignment between external and internal cues that regulate the circadian rhythm.

Difference between ASPD and DSPS:

• melatonin secretion occurs later for people with DSPS

• melatonin secretion occurs earlier for people with ASPD

shift work

an occupation that involves working at unusual hours, such as working overnight

effects of shift work on sleep

• insomnia

• fragmented sleep

• circadian rhythm phase disorder

• quality and quantity of sleep can be adversely affected

difference between shift work disorders and sleep phase disorders

ASPD and DSPS are caused by problems with internal cues, whereas, shift work disorders are caused by external cues as an individual may be required to be awake when its dark and sleep when its light