Chapter 7: Importance of Sleep in Mental Wellbeing

Question 1

Sleep disturbance

Answer 1

• Sleep related problem (disrupts the sleep-wake cycle)
• Can be temporary, occasional or persistent
• E.g. waking from sleep / abnormal behaviour during sleep

Question 2

Sleep disorder

Answer 2

• Persistent sleep disturbance that causes distress in everyday life during normal waking hours
• Classified as either primary or secondary

Question 3

Primary vs secondary sleep disorders

Answer 3

• Primary – cannot be attributed to other conditions
  
  • E.g. regular awakenings due to insomnia (primary)
• Secondary – results from other conditions
  
  • E.g. regular awakenings due to back pain or stress

NOTE: Conditions include mental health / medical problems, illicit drug use, etc.

Question 4

Sleep deprivation

Answer 4

• A state caused by inadequate quantity / quality of sleep, either voluntarily or involuntarily

Question 5

Sleep quantity vs quality

Including subjective and objective measures

Answer 5

• Quantity – amount of sleep
  
  • Obj: duration of the sleep episode
• Quality – how well we feel we have slept
  
  • Sub: how rested / recovered the individual feels
  • Obj: no. interruptions / awakenings during episode

Question 6

Partial vs total sleep deprivation

Answer 6

• Partial – lower quantity / quality of sleep than normal
• Total – no sleep at all over a short or long term period

Question 7

Sleep debt

Answer 7

• Accrued amount of sleep loss from insufficient sleep
• = optimal sleep qty per night - total sleep qty per night

Question 8

Physiological effects of sleep deprivation

Answer 8

• Fatigue and lack of energy
• Trembling hands and slurred speech
• Drooping eyelids, staring and inability to focus eyes
• Headaches and increased pain sensitivity

Question 9

Psychological (affective, behavioural and cognitive) effects of sleep deprivation

Answer 9

• Affective (emotional)
  
  • Amplified emotional responses / outbursts due to poor emotional regulation & increased reactivity
  • Easily irritated, short tempered and moody
  • Decreased empathy and motivation
  • Impaired facial recognition of emotions
• Behavioural
  
  • Slower reaction times (↓ speed and accuracy)
  • Increased risk-taking behaviour & clumsiness
  • Sleep inertia, microsleeps, fatigue & restlessness
  • Poor concentration & ↓ awareness of environment
• Cognitive
  
  • Reduced alertness & ability to stay focused on a task
  • Impaired attention span and learning
  • Impaired memory (encoding not retrieval)
  • More likely to think in irrational ways
  • Poor decision making and problem solving
  • More trouble w simple than complex tasks

Question 10

Why are simple tasks more difficult to complete than complex tasks when partially sleep deprived?

Answer 10

• Simple tasks generally do not require a lot of attention
• When partially sleep deprived, attention is already impaired

Question 11

Effects of full sleep deprivation

Answer 11

• Detrimental (physical & psychological) effects on body
• Can lead to sleep dep psychosis, resulting in depersonalisation (loss of identity) and difficulty coping
• Hallucinations, depression, anxiety & obesity

Question 12

Sleep inertia

‘State of grogginess’

Answer 12

• Temporary period of reduced alertness & performance impairment that occurs immediately after awakening
• Common after a poor night’s sleep, if abruptly awakened or if sleep quantity / quality is insufficient
• Individual typically feels groggy, partly awake & disoriented
• Strongest at wake time (decays rapidly thereafter)
• Motor and cognitive function (e.g. reaction time) can slow
• Worse effects when awakened during N3 than N1 / N2
• Can be experienced after a short nap
• Tends to last longer for sleep deprived individuals

Question 13

Is a person asleep or awake when experiencing inertia?

Answer 13

• Sleep inertia is a sleep-to-wake transition effect
• The individual is considered to be waking, partly awake or awake until it dissipates and the person is fully alert

Question 14

Microsleep

Answer 14

• Very short period (e.g. seconds) of involuntary sleep
• Usually involuntary and unintended
• Common when sleep deprived and experiencing fatigue, excessive sleepiness or a low level of alertness

Question 15

Is a microsleep a mini version of a major sleep episode?

Answer 15

• It is a true sleep state and sleep episode
• But it is not a mini vers of a major sleep ep (major ep = ultradian rythym that comprises NREM / REM periods)

Question 16

Factors that influence recovery from partial sleep deprivation

Answer 16

• Amount of total sleep loss or accrued sleep debt
• Nature of the sleep loss
• When and why sleep loss occurred
• Personal characteristics of the individual involved

NOTE: The effects of sleep dep can be reversed with one night of uninterrupted sleep.

Question 17

REM rebound

Answer 17

• Occurs when deprived of REM sleep specifically
• Typical proportion of REM to NREM may shift
• Dream intensity tends to increase

Question 18

Blood alcohol concentration (BAC)

Answer 18

• Measure of alcohol in body (g of alc/100 mL of blood)
• High BAC results in an induced ASC
• 17hr sleep dep = 0.05% BAC, 24hr sleep dep = 0.10% BAC

Question 19

Circadian rhythm sleep disorders

E.g. DSPS, ASPD and shift work disorder

Answer 19

• Sleep disturbance due to mismatch between sleep-wake pattern & pattern that is desired / required
• Potential causes include …
  
  • Natural change in biol systems regulating the SWC
  • Mismatch between SWC & day-night cycle
  • Mismatch between SWC & school / work schedule

Question 20

Delayed Sleep Phase Syndrome (DSPS)

Answer 20

• Major sleep ep occurs later than desired / convential
• Circadian rythym delayed 2+ hrs despite external cues
• Causes – lifestyle, poor sleep habits, adolescence & jetlag
• Effects – sleep-onset insomnia, excessive sleepiness and difficulty awakening at the desired or necessary time

NOTE: DSPS tends to be resistant to many treatment methods.

Question 21

Why is DSPS more common in adolescence?

Answer 21

• Melatonin release is commonly delayed by up to 2 hrs
• Also blue light exp, homework & after school activities

Question 22

Advanced Sleep Phase Disorder (ASPD)

Answer 22

• Mjr sleep ep occurs earlier than desired / conventional
• Compared to DSPS, those w ASPD are more able to carry on w responsibilities (e.g. school) as it better fits into the societal SWC
• Causes – lifestyle, genetics, old age and jetlag
• Effects – sleep deprivation and daytime sleepiness

NOTE: As is with DSPS, ASPD does not necessarily change one’s quantity or quality of sleep (relative to their age).

Question 23

Shift work disorder

Answer 23

• Occurs when work shifts are constantly scheduled during usual sleep periods; shift overlaps w all / part of sleep period
• Requires adjustment of sleep-wake times to work times
• Effects – total sleep time ↓, insomnia when trying to sleep and excessive sleepiness when required to be awake / alert

NOTE: Shift work that moves forward in time from previous shifts is more ideal as it works with our natural lengthened circadian rhythm.

Question 24

Rotating shift work vs fixed shift work

Answer 24

• Rotating schedules (those that change too frequently) are associated w more sleep disturbances than longer schedules
• Longer schedules enable people to adapt by giving the body ↑ time to reset its SWC and sync w the external environment

Question 25

Bright light therapy

Treatment for circadian rhythm sleep disorders

Answer 25

• Involves exposing eyes to light at certains times with the aim of shifting one’s SWC to a desire / convential time
• Light used is either natural (sunlight) or artificial (light box)
• E.g. evening exposure can stimulate wakefulness for those w ASPD, helping to reset their natural body clock

Question 26

Factors that affect the effectiveness of bright light therapy

Question 27

Sleep hygiene

Sleep habits

Answer 27

• Practices that promote 👍 sleep & daytime alertness
• Establish a relaxing sleep schedule & bedtime routine
• Associate your bed / bedroom with sleep
• Avoid stimulating activities (e.g. vigorous exercise) before bed
• Get up when unable to sleep & avoid naps during the day
• Avoid stimulants (e.g. caffeine) & food before bed
• Exercise during the day
• Improve your sleeping environment
• Ensure adequate exposure to natural light

Question 28

Zeitgebers

‘Time giver’

Answer 28

• Environmental time cues
• E.g. light, temperature and eating / drinking patterns
• Used by the SCN to align circadian rhythms w day-night cycle of external environment (circa rhythm is entrained)
• Can be used to improve sleep-wake patterns & 🧠 wellbeing

Question 29

Entrainment

Answer 29

• Process of adjusting / resetting a biological rhythm to align with external cues or an environmental cycle

Question 30

Light

Zeitgebers

Answer 30

• Daylight (natural) or blue light (natural / artifical)
  
  • Natural – sunlight
  • Artificial – LED lights and electronic devices (e.g. TVs)
• Sleeping w light affects NREM-REM sleep (↓ sleep quality)
• Morning exposure – ↑ wakefulness, ↓ daytime sleepiness and improves mood / memory / alertness
• Evening exp – delays melatonin production, extends sleep onset, ↓ total sleep time, ↑ awakenings and can strain eyes

NOTE: Light is the zeitgeber with the strongest influence on the SWC.

Question 31

Temperature

Zeitgebers

Answer 31

• Body temp control & sleep are closely connected
• Sleep is most likely to occur when core body temp ↓
• A cool room promotes sleep onset and sleep quality
• Around 17° to 18°

Question 32

Eating and drinking patterns

Zeitgebers

Answer 32

• Type, timing and amount of food / drink consumption
• Inconsistencies in these patterns can disrupt the SWC
• Eating just before sleep = disruptive (body still digesting)
• Caffeine stimulates the CNS which can delay sleep onset
• Alcohol can induce drowsiness and sleep onset but can affect sleep duration and quality
• Should be consistently changed to suit the desired SWC