CHAPTER 7: IMPORTANCE OF SLEEP IN MENTAL WELLBEING

Question 1

sleep disturbances

Answer 1

• any sleep-related problem that disrupts an individual’s normal sleep–wake cycle, including problems with sleep onset, waking from sleep and abnormal behaviour occurring during sleep.
• the disruption may be temporary, occasional or persistent.

Question 2

sleep disorder

Answer 2

• when a sleep disturbance is persistent and regularly disrupts sleep
  
  • causing distress or impairment in important areas of everyday life during normal waking hours
• are generally considered serious disturbances to the normal sleep–wake cycle that may impact on the time, amount and/or quality of sleep.

Question 3

primary sleep disorder

Answer 3

• is a persistent sleep disturbance that cannot be attributed to another condition (mental health or legal/illegal drugs)
• occurs in its own right and can not be explained by another condition
• e.g: sleep terrors, sleep walking, sleep apnea

Question 4

secondary sleep disorder

Answer 4

• involves a sleep disturbance that is a by-product of or results from another condition, or use of substances
• e.g: back pain, bladder problem, anxiety, depression

Question 5

sleep deprivation

Answer 5

general term used to describe a state caused by inadequate quantity or quality of sleep either voluntary or involuntary.
* quantity- amount of sleep (objective measure)
* quality- how well we feel we have slept (subjective measure)

Question 6

partial sleep deprivation

Answer 6

• involves having less sleep (either quantity or quality) than what is normally required
• may occur periodically or persistently over the short-term or long-term.
• e.g someone may have too little sleep for one or more days, weeks, months and so on.
• most sleep disorders are associated with partial sleep deprivation that occur routinely over a prolonged period.

Question 7

total sleep deprivation

Answer 7

• involves not having any sleep at all over a short-term or long-term period: the person stays awake for one or more days or weeks.
• this usually takes place under extreme conditions, such as when people try to break records, often using stimulants to help them stay awake.

Question 8

sleep debt

Answer 8

• is the accumulated amount of sleep loss from insufficient sleep.
• the difference between the amount of sleep that is needed to function at an optimal level and the amount a person actually gets.
• e.g: a nightly sleep debt of 60 minutes between Monday and Friday would add up to a total sleep debt of 5 hours.
• generally, after a period of sleep deprivation, only some of the sleep debt needs to be recovered.

Question 9

affective functioning

Answer 9

• amplified emotional responses: emotional reactions may be too quick and more intense or exaggerated, often out of proportion to how we would ordinarily react when not sleep deprived.
• when we haven’t slept well:
  
  • our emotional response threshold can be lowered, increasing our emotional reactivity and making us more likely to overreact to relatively neutral events.
  • has a detrimental effect on our ability to sort out the unimportant from the important, and this can lead to poor judgments in relation to our emotional responses.

Question 10

behavioural functioning

Answer 10

• sleep inertia — a temporary period of reduced alertness and performance impairment that occurs immediately after awakening. is a sleep-to-wake transition effect that can follow a poor
  night’s sleep, especially if abruptly awoken.
• fatigue — a persistent feeling of tiredness and lack of energy.
  
  • difficulty maintaining concentration, reduced
    awareness of the environment, reduced efficiency, slower than normal reaction times and make more mistakes.
• the predominant behavioural effect of sleep deprivation over a period of time is excessive sleepiness when awake
• microsleep — a sleep episode that lasts for a few seconds. during a microsleep, a person will briefly close their eyes partially or fully
• increased risk-taking behaviour: researchers have found that pedestrian behaviour is generally riskier when sleep deprived.

Question 11

cognitive functioning

Answer 11

• tend to experience lapses in sustained attention and reduced ability to divide our attention on tasks
  that require simultaneous attention to multiple sources of information.
• tasks often begin well, but performance tends to deteriorate as task duration increases.
• the greater the sleep deprivation, the more likely it is that attention will be impaired and that errors associated with loss of attention will increase. This is even more likely when a task lacks interest or complexity.
• more likely to think in irrational ways, have difficulty making decisions and solving problems that require creative thinking.
• more time to analyse situations and respond physically to events.
• loss of situational awareness and overlook important details.
• impaired learning and memory.

Question 12

circadian rhythm sleep disorders (dsps and aspd)

Answer 12

• a group of sleep disorders involving sleep disturbance primarily due to a mismatch between an individual’s sleep–wake pattern and the pattern that is desired or required.
• the disturbance may be caused by:
  
  • a naturally occurring change or a malfunction of biological mechanisms or processes regulating the sleep–wake cycle
  • a mismatch between an individual’s sleep–wake cycle and the day–night cycle of their physical environment
  • a mismatch between an individual’s sleep–wake cycle and the sleep–wake schedule required by their school, work or social schedule.
• individual usually complains of insomnia, excessive sleepiness or both.

Question 13

delayed sleep phase syndrome (DSPS)

Answer 13

• condition in which the major sleep episode is delayed in relation to the desired sleep time or what is considered a conventional time.
• there is a natural tendency to go to sleep later and therefore wake up later than what is normal according to ‘society’s clock’.
• prominent symptoms: sleep-onset insomnia, difficulty awakening at the desired or necessary time, and excessive sleepiness.

Question 14

dsps cause

Answer 14

• DSPS tends to emerge or worsen during adolescence and continue into early adulthood.
• estimates of its prevalence among adolescents and young adults range from 7–15%. It affects both males and females equally.
• DSPS is the most common of all the circadian rhythm phase disturbances. while it involves a circadian rhythm disruption or malfunction, the specific cause of this dysfunction is not entirely understood.

Question 15

advanced sleep phase disorder (ASPD)

Answer 15

• a persistent disturbance of the sleep–wake cycle characterised by advance of the major sleep episode to an earlier time compared to desired or conventional sleep times.
• the disorder results in compelling evening sleepiness, early sleep onset, and awakening earlier than the desired or necessary times.
• ASPD is a rare disorder but more common among older people (about 1% of males and females in middle age or older).
  
  • The circadian rhythm and sleep–wake times tend to naturally advance to some degree in older people, which may account for the increased prevalence of the advanced sleep phase in this population.

Question 16

cause of ASPD

Answer 16

• has been proposed that it may be due to an age-related deterioration in the biological clock (SCN) that regulates the sleep–wake cycle, the reduction in melatonin production that is evident among older people and/or a shift in the circadian timing of melatonin secretion to 2–4 hours earlier than normal.
• may be associated with decreased exposure
  to light in the late afternoon/early evening and increased exposure to early morning light due to early morning awakenings

Question 17

shift work disorder

Answer 17

• a circadian rhythm sleep disorder that occurs as a result of work shifts being regularly scheduled during the usual sleep period.
• work shifts overlap with all or part of the sleep period, requiring adjustment of sleep and wake times to the work times.
• primary symptoms:
  
  • insomnia when a person is trying to go to sleep
  • excessive sleepiness when a person needs to be awake and alert.
  • associated with a reduction in total sleep time

Question 18

bright light therapy

Answer 18

involves timed exposure of the eyes to intense but safe amounts of light. When used for circadian
rhythm sleep disorders, the aim is to shift an individual’s sleep–wake cycle to a desired schedule, typically the day–night cycle of their physical environment.
- right time of day at the right intensity for the right amount of time.

Question 19

sleep hygiene

Answer 19

• involves practices that tend to improve and maintain good sleep and full daytime alertness.
• includes behaviours and environmental factors that can be adjusted to help with a good night’s sleep and waking feeling rested and ready to take on the day’s activities.
• sleep hygiene is often used interchangeably with sleep habits because it involves changing basic lifestyle habits that influence sleep onset, good quality sleep and alertness during the normal waking period.

Question 20

zeitgebers

Answer 20

environmental time cues that can be used to
improve sleep–wake patterns and consequently mental wellbeing.

Question 21

entrainment

Answer 21

zeitgebers in the external environment are used by the SCN to adjust circadian rhythms to a 24-hour day. The SCN is believed to do this on a daily basis. When the SCN adjusts or resets the sleep–wake cycle to match the environmental day-–night cycle through the influence of a zeitgeber, the circadian rhythm is said to be entrained
- e.g: all our circadian rhythms are entrained to the regular 24-hour, day–night cycle of our external environment.

Question 22

daylight

Answer 22

• natural light from the sun in the course of a typical day, our circadian sleep–wake cycle becomes closely synchronised with sunrise and sunset, keeping us awake during the day and sleeping when it’s dark. The specific timing of the cycle, however, is influenced by the timing of the light exposure.
• it is also best to sleep in as much darkness as possible, ideally pitch darkness. Sleeping in daylight, even at a low level (or with a light on), tends to interfere with the NREM–REM sleep cycle and adversely affects sleep quality.
• e.g: it can cause an increase in the duration of NREM stage 1 sleep, less deep sleep and therefore more shallow sleep, and frequent arousals resulting in more fragmented sleep.

Question 23

blue light

Answer 23

• keeps us alert by suppressing the secretion of melatonin that makes us feel drowsy.
• helpful during the day, it becomes unhelpful at night when we’re trying to sleep.
• too much exposure to blue light in the evening disrupts our circadian rhythms leaving us feeling alert instead of drowsy and ready for sleep.
• chronic exposure to blue light before the natural or desired sleep time may have more serious implications for the circadian sleep phase. It can cause a phase shift resulting in the delayed sleep syndrome.
• associated with use of electronic devices when in bed is one of the contributory factors to the sleep–wake cycle shift experienced by about 7% of
  teenagers.

Question 24

temperature

Answer 24

• sleep is most likely to occur when core body temperature decreases, and much less likely to occur during the rises when the body is preparing for wakefulness.
• about two hours before falling asleep, our core body temperature starts to decrease under circadian control, coinciding with the secretion of melatonin.
• research evidence suggests that a temperature of around 18° celsius is best for sleep

Question 25

eating and drinking

Answer 25

• food can be disruptive just before sleep. Our digestive system also follows a circadian rhythm linked to the day–night cycle. It is ready to digest food during the day, but not at night time.
• although it is important to not be hungry at bedtime, it can be harder to fall asleep if we have a full stomach and our body is still digesting a big dinner.
• caffeine: takes a long time for the body to break down caffeine (4–6 hours), so drinking caffeine during the afternoon in particular can affect sleep onset at night.
• alcohol: can induce drowsiness and assist sleep onset, but alcohol can shorten overall sleep duration and affect sleep quality. impairs sleep quality during the second half of the night in the second half of the night-frequent awakenings, night sweats, nightmares, headaches and is much less restful.