Sleep disorders

Sleep disorders are disorders that cause disturbances in sleep. They can be divided into two main categories: dyssomnias (interfering with the amount and/or timing of sleep) and parasomnias (odd behaviors that occur during sleep).

Background information

Sleep

Sleep is necessary for humans. The need for sleep has been theorized to be for several purposes:

• Evolutionary - sleeping in darkness when predators lurked about kept ancestors safe
• Memory consolidation - during sleep, our brains organize, consolidate, and weed out some of the input from the day (especially during REM - rapid eye movement)
• Energy conservation - sleeping allows us to require less fuel than we would if we were active around the clock
• Cellular repair - sleep helps restore and repair brain tissue, and cellular regeneration increases during sleep
  • Children grow during sleep

Sleep physiology

Suprachiasmatic nucleus (SCN) are a cluster of neurons in the hypothalamus of one's brain.

The SCN responds to changes in light:

• Decreases melatonin from the pineal gland in the morning and increase melatonin in the night
• Artificial light also affects SCN

Pineal gland creates melatonin.

Stages of sleep

EEG stages of sleep:

• Stage 1 - drowsy, half awake
• Stage 2 - asleep, sometimes REM happens
• Stage 3 - deep sleep
• Stage 4 - very deep sleep

Types of brain waves

• Alpha - eyes closed, but awake - brain slows down, shows regular alpha waves
  • Can be produced by meditation
• Beta - awake and alert
• Theta waves - sleep stages 1-2
  • Sleep spindles - the “drop” you feel when falling asleep
  • Early, light sleep
  • Also produced by daydreaming
• Delta waves
  • Deep sleep (stages 3-4)
  • Slow wave sleep - brain activity slows down and produces low, slow delta waves
  • Many parasomnias (sleep terrors, sleepwalking, and sleep-talking) occur during delta wave sleep
    • More common in children

REM sleep

Half of sleep disorders involve disruption of REM sleep. Selective deprivation of REM sleep causes hallucinations and bad things.

Sleep deprivation will modify sleep architecture to prioritize REM, causing REM rebound, a natural function of the human body that prioritizes REM sleep when sleep deprived.

During REM, the brain is asleep, but engages in fast and regular beta waves, much like in an awake-aroused state.

Dreaming only happens during REM, though it's unclear how much dreaming occurs during REM.

During REM, the brain's waves look most like an awake brain.

Sleep paralysis during REM protects you from actually performing the muscle movements you dream of.

Amount of REM sleep decreases across lifespan, meaning less memory consolidation as you get older.

Dreams and dreaming

Psychoanalytic view - dreams represent a window into the unconscious; manifest vs. symbolic (latent) content

• Manifest - on the surface, what you see
• Latent - symbolic, hidden
• Mistake: symbols of dreams were universal symbols

Cognitive view - dreams constructed from your daily issues

• Doesn’t make sense, but combines things from the day randomly
• Receives some support

Biological views - dreams represent the attempt of the cortex to interpret the random neural firing of the brain during sleep (activation-synthesis theory)

• Or dreams provide the sleeping brain with periodic stimulation to develop and preserve neural pathways

REM sleep a fairly well-understood process at this point. The brain goes through a series of specific neurological activities that result in consolidating learning from new information and performing other housekeeping.

Do we need to dream? Researchers agree that we need REM. This is why REM rebound, selective REM deprivation, and REM intrusions happen. REM and dreaming go hand in hand. It only remains unclear whether dreaming is a necessary aspect of the REM process or a side effect of that process.

80% of the dreams we remember are negative.

Sleep disorders list

There are two kids of sleep disorders:

Dyssomnias, which are related to the timing of sleep and amount of sleep one receives.

• Primary insomnia: trouble falling asleep or maintaining sleep. Three kinds:
  • Have trouble falling asleep
  • Wake up too often at night
  • Terminal insomnia - waking up too early
• Primary hypersomnia: getting too much sleep
• Narcolepsy: suddenly get sleep attacks during the day
  • Can't control falling asleep during the day
  • Requires medical treatment; could be deadly if not addressed
• Breathing-related sleep disorder
  • Sleep apnea - stopping breathing while sleeping
    • Dangerous because oxygen deprivation affects person’s thinking abilities
    • Associated with obesity
• Circadian rhythm sleep disorder
  • Disregulated circadian rhythm causes inability to sleep at night, maybe sleep at date
  • Easier to advance their sleep time later and later until it’s accurate again; forward is easier than backwards
  • Usually, something artificial makes this happen - late shifts, travelling, etc.
  • No amount of time this occurs for is factored in, just whether you can fix this yourself or not
• Dyssomnia not otherwise specified

The difference between hypersomnia and narcolepsy is that narcolepsy involves sleep attacks (one can’t stay awake and cannot control falling asleep), whereas hypersomnia refers to oversleeping in general that's not necessarily as specific as narcolepsy's symptoms.

Parasomnias, which are the odd behaviors that may occur to one while sleeping. Parasomnias are mostly occurrent among children.

• Nightmare disorder: when nightmares disrupt sleep enough to be an interference
  • Caused by scary dreams occurring during REM sleep
  • Sense of distress during dreams
  • May cause avoidance from sleeping
  • Incredibly treatable - lucid dreaming is a treatment
  • Nightmares usually happen later in night
• Sleep terror disorder:
  • Unlike a nightmare, sleep terrors don’t occur during REM sleep and are not dreams.
  • Happen during delta wave sleep
  • Sleep terrors usually happen at the beginning of night
  • Much more common in children, outgrown in adolescence
  • Very genetic, happens commonly in afflicted families
  • During a night terror, the afflicted cannot read - this is only temporary and does not cause further issues
  • Sleep hygiene practices reduce sleep terrors significantly
  • When night terrors happen, reassure the kid, dab a damp washcloth on cheeks to wake them up
  • People will usually have little memory of the sleep terror
• Sleep eating:
  • Very disorganized eating
  • Will find food on floor
  • Occurs during delta wave sleep - the person will be "zombified"
  • Common among children
• Sleepwalking disorder:
  • Usually occurs among children
  • Happens during delta wave sleep
  • Cause: natural muscular paralysis does not happen, so people will act out their dream
  • What you dream about can be acted out in REM. It's more organized; one is able to produce complex behavior in REM. Theoretically, one could potentially murder someone with this disorder.
• Bruxism: grinding of teeth during sleep
  • Happens during delta wave sleep
• Parasomnia not otherwise specified
  • Sleep paralysis
  • Hypnogogic/pompic hallucinations

Differentiating between the different delta wave sleep disorders can be done by examining the afflicted:

• Sleeptalking - pretty anxious
• Sleepwalking - not really anxious
• Sleep terrors - very anxious episode

Sleep disorders are either related to another mental disorder or due to a general medical condition. Substance-induced sleep disorders are also a possibility.

Primary vs. secondary

Sleep disorders can either be primary or secondary.

Primary means there is no underlying cause.

Secondary means it has another root cause.

Dyssomnias vs. parasomnias

• Dyssomnias often are secondary, while parasomnias often are primary.
• Parasomnias are made worse by medications, but usually not caused by it.
• Parasomnias due to neurological development and family history/genetics.
  • Especially prevalent in children
  • Does not lead to mental disorders for children in the future; they naturally get better