8B- circadian rhythm sleep disorders

Question 1

circadian rhythm sleep disorders

Answer 1

a category of sleep disorders in which sleep is disrupted because the circadian rhythm and a person’s sleep wake schedule are misaligned

Question 2

bright light therapy

Answer 2

a therapy to treat a sleep disorder in which the person is exposed to a bright light to reset the sleep wake cycle

Question 3

delayed sleep phase syndrome

Answer 3

a circadian rhythm sleep disorder characterised by a delay in the timing of sleep onset and awakening compared with the timing that is desired

Question 4

advanced sleep phase disorder

Answer 4

a circadian rhythm sleep disorder characterised by an advance in the timing of sleep onset and awakening compared to the timing that is desired

Question 5

shift work

Answer 5

work that regularly takes place outside of normal business hours particularly at night and the very early morning, can cause a circadian rhythm sleep disorder

Question 6

what is a circadian phase disorder?

Answer 6

Circadian phase disorder refers to sleep disorders that involve disruptions to a person’s sleep-wake cycle as there is a mismatch between a person’s normal sleep-wake pattern (reality) and the sleep-wake pattern that is required of them (expectation).

Question 7

what can circadian rhythm disorders cause?

Answer 7

distress/dysfunction
excessive sleepiness/insomnia/ impairment in functioning
harder to function day to day

Question 8

what are 3 circadian phase disorders?

Answer 8

advanced sleep phase disorder
delayed sleep phase syndrome
shift work

Question 9

what can circadian rhythm sleep disorders be treated with?

Answer 9

bright light therapy which involves exposing a person to light for a specific amount of time to reset the sleep wake cycle. strategic exposure to light prompts the wake inducing biological mechanisms involving the circadian rhythm and suprachiasmatic nucleus and delays melatonin release, promoting wakefulness

Question 10

what are some light sources for BLT

Answer 10

safe but artificial source from a specifically designed light box, desk lamp, floor lamp, visor hat with attached light or dawn simulator light
or may be natural sunlight if deemed reliable
ideal length and timing of light exposure is dependent on the type of disorder being treated

Question 11

what is DSPS

Answer 11

delayed sleep phase syndrome is a sleep disorder characterised by a delay in timing of sleep onset and awakening compared to the desired timing
delay is usually 2 or more hours, with a person falling asleep later than required or conventionally accepted, causing a delay in awakening

Question 12

what does the delay in sleep onset contribute to?

Answer 12

a sleep disorder when a person is unable to achieve the recommended amount of sleep because they have to wake up for work/school

Question 13

how does DSPS occur

Answer 13

because the internal body clock doesn’t match the external cues like light and darkness. this delays sleep and wake times

Question 14

give an example of DSPS

Answer 14

instead of sleeping at 10 and waking at 8, they may sleep at 1 and wake up at 11

Question 15

when is DSPS seen throughout the lifespan

Answer 15

adolescent sleep-wake cycle shift

Question 16

in order to be diagnosed what are the conditions?

Answer 16

must experience symptoms for more than 3 months
oftentimes, this also implies symptoms are not getting better, or are worsening.

Question 17

what are some predisposing factors for DSPS?

Answer 17

age
longer than average circadian rhythm
delayed night time signal to the SCN, which delays melatonin release
less sensitive to morning light, would have a lack of light cues to the SCN to signal a reduction in melatonin release

Question 18

how can bright light therapy be used as a treatment for DSPS?

Answer 18

exposed to the bright light source in the morning at an appropriate awakening time.
external cue to the SCN, promoting wakefulness by sending signals to release cortisol
helps the SCN send signals for melatonin release at an earlier and more appropriate sleeping time, promoting sleep

Question 19

what is ASPD

Answer 19

advanced sleep phase disorder is a circadian rhythm sleep disorder characterised by an advance in the timing of sleep onset and awakening compared to the desired timing

Question 20

how does ASPD occur?

Answer 20

internal body clock is set earlier than normal, making them feel tired earlier in the evening and causing them to wake up earlier in the morning

Question 21

give an example of ASPD

Answer 21

instead of sleeping at 10 and waking at 8, they sleep at 8 and wake at 6

Question 22

when they attempt to adhere to a later bedtime what occurs?

Answer 22

they will continue to have an early wake time due to the shift in circadian rhythm

Question 23

how is ASPD perpetuated

Answer 23

a persons adverse exposure to light can maintain their undesired advance circadian rhythm. by going to bed early and then waking early, a person isn’t exposed to the regular evening low light and morning bright light signals maintain the disorder

Question 24

what are some symptoms and how can they increase in severity?

Answer 24

symptoms can get more severe when work or social demands require a schedule that doesn’t match the persons natural sleep-wake cycle

Question 25

how can bright light therapy be used as a treatment for ASPD?

Answer 25

exposed to the bright light source in the evening when feeling sleeping
acts as an external cue to the SCN and promotes wakefulness, causing a delayed melatonin release to occur at a more appropriate sleeping time
encourages the SCN to signal cortisol release later in the morning at a more appropriate time

Question 26

how can shift work cause a circadian rhythm sleep disorder?

Answer 26

when a person regularly works outside of normal business hours, particularly at night and the very early morning. This can include a consistent night shift or a rotating schedule, in round-the-clock professions such as health care, hospitality, factory work, transport and travel.

Question 27

what does shift work do to circadian rhythms

Answer 27

can put a person’s sleep wake schedule in direct opposition to the regular day-night environmental hours resulting in distress and dysfunction due to excessive sleepiness and impaired sleep at home afterwards

Question 28

what can shift work lead to in terms of cognitive effects

Answer 28

sleep disruption can lead to decreased judgement, poor decision making which then leads to behavioural effects like making more errors or accidents which then leads to affective effects like being unable to control ones temper or being easily irritated

Question 29

what biological impacts does shift work have

Answer 29

People who do shift work tend to disrupt their sleep-wake cycle as the body is not biologically
programmed to stay awake well into the late hours
of the night. This disruption in how a person is
exposed to light (working at night, sleeping in daytime) also disrupts the normal release of melatonin.

Question 30

what cues impact shift work?

Answer 30

Shift work disorders are caused by problems with external cues as a person needs to be awake when it’s dark outside and sleep when it’s light outside.

Question 31

how much of the population does shift work impact?

Answer 31

5-10% of the population- they work during nights particularly those middle aged-

Question 32

diagnosis of shift work

Answer 32

Diagnosis depends on how severe the symptoms are and the level of distress experienced by the person.

Question 33

what are some consequences of a circadian rhythm disorder caused by shift work

Answer 33

poor performance at work, interpersonal problems, increased risk of accidents, poor mental wellbeing

Question 34

prolonged shift work and physical health problems links

Answer 34

research has consistently found a link between prolonged shift work and physical health problems like gastrointestinal disorders, cardiovascular diseases, diabetes and cancer

Question 35

when do symptoms reduce for shift work?

Answer 35

when they can spend longer on one shift rotation before changing. Where rotating schedules are required, they should ideally shift forward, such as from morning shift, to afternoon shift, to evening shift, to allow a person the best chance to adjust. If a person working night shifts can commit to a more nocturnal routine for their social and other commitments, it may help their sleep–wake cycle become more consistent, and reduce symptoms. When a person returns to a typical, consistent daytime shift routine, then their symptoms can also resolve.

Question 36

how can BLT be used as treatment for shift work related sleep disorders

Answer 36

an individual is best to be exposed to the bright light source before beginning their shift at work to promote wakefulness and alertness
this promotes sleepiness at a later more suitable time, whether that be morning or afternoon

Question 37

What are circadian rhythm sleep disorders?

Answer 37

Circadian rhythm sleep disorders are a category of sleep disorders characterised by a persistent pattern of sleep disruption when the circadian rhythm and the sleep-wake schedule are misaligned.

Question 38

What is the difference between a Delayed Sleep Phase Syndrome and an Advanced Sleep Phase Disorder?

Answer 38

A Delayed Sleep Phase Syndrome causes a person to fall asleep later than desired, whereas an Advanced Sleep Phase Disorder causes a person to fall asleep earlier than desired.

Question 39

Describe shift work as a cause of circadian rhythm sleep disorder.

Answer 39

Shift work is a circadian rhythm sleep disorder characterised by working outside of the normal business hours, particularly at night and the very early morning, on a regular basis.

Question 40

Which sleep disorders can bright light therapy treat?

Answer 40

Bright light therapy can treat circadian rhythm sleep disorders.

Question 41

Explain how the hospital’s bedtime routine involving lights would have aided those with DSPS

Answer 41

The hospital consistently turns the lights off at 9 p.m., which would help induce the release of melatonin earlier in the night for patients, resulting in her feeling sleepy earlier. The hospital consistently turns the lights on at 6 a.m., which would help inhibit the release of melatonin in the early morning, resulting in patients feeling more awake.

Question 42

Mila has chosen to work a permanent night shift, beginning at 9 p.m. every night for the duration of the project. suggest a strategy for Mila’s mobile phone use that could help Mila achieve a better sleep during daylight hours.

Answer 42

Mila could ensure that she does not use her mobile phone before sleep or uses a night mode or other screen filter option, as well as ‘muting’ the volume so she is not disrupted during her sleep. She could also use the light from the phone in the evening while she is working to decrease melatonin release and promote wakefulness.