Ch 19: Sleep-Wake Disorders

What is the major consequence of acute or chronic sleep reduction?

excessive sleepiness, which can impact social/work functioning and increase accident/injury risk

What causes sleep restriction?

shift work, sleep disorders, medications, alcohol/substance use, and medical or psychiatric disorders

Define sleep deprivation.

Discrepancy between hours of sleep obtained and required for optimal functioning, accompanied by impaired functioning.

Why is comprehensive sleep evaluation important in mental health disorders?

Chronic sleep deprivation can mimic psychiatric symptoms, leading to misdiagnosis or inappropriate medication changes.

Give an example of sleep loss mimicking psychiatric symptoms.

A patient with psychosis may have increased hallucinations from poor sleep, but the cause could be unstable housing rather than medication need.

List short-term consequences of sleep disruption

Increased stress responsivity, somatic pain, reduced quality of life, emotional distress, mood disorders, cognitive/memory/performance deficits.

List long-term consequences of sleep disruption in healthy individuals.

Cardiovascular disease, weight-related issues, metabolic syndrome, type 2 diabetes, colorectal cancer, increased all-cause mortality.

How does sleep deprivation affect children and adolescents differently?

Children: behavioral problems, impaired cognition.
Adolescents: emotional/social issues, poor school performance, risk-taking behaviors.

How does sleep loss contribute to diabetes and obesity?

alters glucose metabolism, decreases energy expenditure, increases appetite via leptin and ghrelin dysregulation.

How is sleep deprivation comparable to alcohol intoxication?

17–19+ hours awake produces psychomotor deficits equal to BACs of 0.05%–0.1%.

What is microsleep?

Brief episodes (1–10 sec) of sleep during wakefulness, causing reduced performance and increased error risk.

why is consistency in sleep timing important?

regular bedtime/wake-up schedules support health; irregular sleep timing is linked to negative metabolic changes

What are metabolic consequences of irregular sleep patterns?

Lower HDL cholesterol, higher waist circumference, increased BP, higher total triglycerides, and fasting glucose.

How is “too much sleep” defined in adults?

sleeping more than 9 hours per night

How is childhood obesity linked to excessive sleep?

long sleep duration may impair metabolism and increase obesity risk

How does sleeping ≥10 hours affect adult health?

Increases risk for metabolic syndrome (abdominal fat, hypertension, low HDL, high glucose, high triglycerides).

What non-metabolic issues are linked to excessive sleep?

depression, headaches, and increased mortality from medical conditions

What conditions can cause excessive sleep?

sleep apnea, restless leg syndrome, bruxism, pain, narcolepsy, hypersomnolence

How is sleep defined behaviorally?

Low or absent motor activity, reduced response to environmental stimuli, and closed eyes.

How is sleep measured neurophysiologically?

with an EEG, which identifies brain wave patterns, eye movements, and muscle tone

What are the two main physiological states of sleep?

Non–rapid eye movement (NREM) sleep and rapid eye movement (REM) sleep.

what percentage of total sleep time in Stage 1 (N1) and what are its features?

2–5% of total sleep time; brief transition from wakefulness to sleep, reduced body temp, muscle relaxation, slow rolling eye movements, easily aroused.

What is sleep latency?

The time it takes to fall asleep.

What percentage of total sleep time is Stage 2 (N2) and what are its features?

45–55%; HR and RR decline, harder to arouse than in Stage 1.

What percentage of total sleep time is Stage 3 (N3) and what are its features?

13–23%; slow wave/delta sleep, reduced HR, RR, BP, low responsiveness, restorative sleep with reduced sympathetic activity.

What percentage of total sleep is NREM sleep overall?

75–80%.

What percentage of total sleep is REM sleep and what are its characteristics?

20–25%; muscle atonia, bursts of REM, myoclonic twitches, dreaming, autonomic variability.

Why is muscle atonia in REM sleep important?

It prevents the physical acting out of dreams and nightmares.

How does NREM and REM alternate during the night?

Four to six cycles of NREM and REM occur over 90–120-minute intervals.

When does the shortest REM period occur, and how long does it last?

60–90 minutes after sleep onset; lasts a few minutes.

What is sleep architecture?

The structural organization of NREM and REM sleep, often shown on a hypnogram.

What is sleep fragmentation?

Disruption of sleep stages with excessive stage 1 sleep, multiple arousals, and frequent stage shifts.

What psychiatric changes are linked to altered sleep cycles in depression?

Reduced latency to REM sleep and decreased percentage of slow wave sleep.

What is unusual about sleep onset in narcolepsy?

Patients often enter sleep directly into REM rather than NREM.

How do benzodiazepines and antidepressants affect sleep stages?

Benzodiazepines suppress slow wave sleep; serotonergic antidepressants suppress REM sleep.

What are the two processes that regulate sleep and wakefulness?

homeostatic process (sleep drive) and circadian process (wake drive)

What determines the strength of the homeostatic sleep drive?

Number of hours awake; longer wakefulness → stronger sleep drive

What are circadian drives and what influences them?

near-24-hour cycles promoting wakefulness, influenced by endogenous rhythms and environmental cues

Name the wake-promoting neurotransmitters.

Dopamine, norepinephrine, serotonin, acetylcholine, histamine, glutamate, hypocretin/orexin.

Name the sleep-promoting neurotransmitters.

adenosine, GABA, galanin

How much sleep do most adults require?

7-8 hours for optimal functioning

When is sleep testing typically indicated?

when a patient has sleep disturbances or excessive sleepiness that impairs social and vocational functioning

What is the most common diagnostic procedure for sleep disorders?

polysomnography

What does polysomnography diagnose and evaluate?

sleep-related breathing disorders and nocturnal seizure disorders

How is polysomnography performed?

One or two nights in a sleep lab with electrodes and monitors on the head, chest, and legs; records brain waves, eye movement, muscle tone, heart rhythm, and breathing.

What is the multiple sleep latency test (MSLT) used for?

To objectively measure daytime sleepiness in a sleep-conducive setting.

When is MSLT typically performed?

The day after a polysomnography evaluation, especially if narcolepsy is suspected.

What does the maintenance of wakefulness test (MWT) evaluate?

the patient’s ability to remain awake in a situation conducive to sleep

For what professions is the MWT especially important?

Jobs where sleepiness poses a public safety risk, such as airline pilots.

What is actigraphy?

A wristwatch-type tracker that records body movement over time to assess sleep patterns and duration.

For which conditions is actigraphy most useful?

circadian rhythm disorders and insomnia

How is insomnia disorder defined?

Dissatisfaction with the quantity or quality of sleep

What percentage of adults may be affected by insomnia?

up to 45% of adults

Which groups are more frequently affected by insomnia?

females and older adults

What assessment model is recommended for understanding causes of insomnia?

Spielman’s 3P model of insomnia

What are the three factors in Spielman’s 3P model?

Predisposing, precipitating, and perpetuating factors

What are predisposing factors in insomnia?

Individual factors creating vulnerability, such as prior poor-quality sleep, history of depression/anxiety, hyperarousal, being a light sleeper, or a night owl

What are precipitating factors in insomnia?

External events that trigger insomnia, such as personal/vocational difficulties, medical/psychiatric disorders, grief, and role changes (e.g., retirement).

What are perpetuating factors in insomnia?

Behaviors or attributes that maintain insomnia, such as excessive caffeine/alcohol use, spending too much time in bed, frequent napping, and worrying about insomnia’s consequences.

What is the core complaint required for a DSM-5 diagnosis of insomnia disorder?

A predominant complaint of dissatisfaction with sleep quantity or quality.

What symptoms can the dissatisfaction with sleep involve (DSM-5 Insomnia Disorder Criterion A)

• Difficulty initiating sleep (children: without caregiver intervention).

• Difficulty maintaining sleep (frequent awakenings or trouble returning to sleep; children: without caregiver intervention).

• Early-morning awakening with inability to return to sleep.

What functional impact is required for DSM-5 insomnia disorder?

Sleep disturbance causes clinically significant distress or impairment in social, occupational, educational, academic, behavioral, or other important areas of functioning.

How often must sleep difficulties occur for a DSM-5 insomnia disorder diagnosis?

At least three nights per week.

How long must symptoms persist for DSM-5 insomnia disorder?

at least 3 months

What condition regarding sleep opportunity is required for DSM-5 insomnia disorder?

sleep difficulty occurs despite adequate opportunity for sleep

How does DSM-5 insomnia disorder rule out other primary sleep disorders?

The insomnia is not better explained by, and does not occur exclusively during, another sleep-wake disorder (e.g., narcolepsy, breathing-related sleep disorder, circadian rhythm sleep-wake disorder, parasomnia).

How does DSM-5 insomnia disorder rule out substances as a cause?

The insomnia is not attributable to the physiological effects of a substance (e.g., drug of abuse, medication)

How does DSM-5 insomnia disorder rule out mental or medical disorders?

coexisting mental disorders and medical conditions do not adequately explain the insomnia complaint

What are the DSM-5 specifiers for insomnia disorder?

• With nonsleep disorder mental comorbidity (including substance use disorders)

• With other medical comorbidity

• With other sleep disorder

What are the primary non-pharmacological interventions for insomnia disorder?

• Improving sleep hygiene

• Shutting off electronics before bed

• Avoiding exercise and meals immediately prior to sleep

• Practicing relaxation techniques

• Cognitive behavioral therapy (CBT)

• CBT-I (specialized CBT for insomnia)

Why is CBT-I recommended for insomnia?

CBT-I addresses the thoughts, behaviors, and habits that contribute to insomnia, providing a long-term solution without reliance on medication.

What are common pharmacological interventions for insomnia disorder?

• Antihistamines

• Sedative-hypnotics (short-term use)

  • Zolpidem tartrate

  • Eszopiclone

  • Zaleplon

• Melatonin

• Melatonin agonist (ramelteon)

Why are sedative-hypnotics recommended only for short-term use in insomnia?

To avoid tolerance, dependence, and potential side effects such as daytime sedation and cognitive impairment.

What is hypersomnolence disorder?

A chronic sleep disorder (≥3 months) characterized by excessive daytime sleepiness despite adequate or prolonged nighttime sleep

When does hypersomnolence disorder typically begin?

Young adulthood.

Key symptoms of hypersomnolence disorder?

• Recurrent periods of sleep or unintended lapses into sleep

• Frequent napping

• Prolonged main sleep (>9 hours)

• Nonrefreshing, nonrestorative sleep

• Difficulty achieving full alertness during wake periods

How does hypersomnolence disorder affect functioning?

Causes significant impairment in social/vocational functioning, reduces enjoyment of relationships, decreases workplace productivity, increases cognitive impairment, and raises risk of accidents or injury

Nonpharmacological treatment for hypersomnolence disorder?

Maintain a regular sleep-wake schedule with ample sleep opportunity (some benefit from 10+ hours).

Pharmacological treatment for hypersomnolence disorder?

• Long-acting amphetamine-based stimulants (e.g., methylphenidate)

• Nonamphetamine-based stimulants (e.g., modafinil [Provigil])

What is narcolepsy?

A rare sleep disorder (<0.05% prevalence) characterized by an uncontrollable urge to sleep, typically starting before young adulthood and persisting for life.

Is narcolepsy more common in men or women?

Slightly more common in men.

Key symptoms of narcolepsy?

• Disturbed nighttime sleep with multiple awakenings

• Automatic behaviors with memory lapses

• Feeling refreshed upon waking but sleepy again in 2–3 hours

• Hypocretin deficiency in cerebrospinal fluid (objective marker)

How does narcolepsy differ from other hypersomnia disorders?

narcolepsy patients feel rested after sleep; other hypersomnia disorders do not

What is cataplexy?

Brief episodes of bilateral muscle weakness without loss of consciousness, often triggered by strong emotions (e.g., laughter, anger, fear, joy).

What causes cataplexy?

Likely due to REM sleep paralysis occurring during wakefulness.

Other classic symptoms of narcolepsy besides cataplexy?

• Hypnagogic hallucinations: false sensory perceptions at sleep onset.

• Sleep paralysis: inability to move or speak during sleep–wake transitions.

Nonpharmacological treatments for narcolepsy?

scheduled naps, exercise, and a balanced diet

FDA-approved stimulant medications for excessive daytime sleepiness in narcolepsy?

Modafinil, armodafinil, methylphenidate, amphetamine.

Nonstimulant medications for narcolepsy-related daytime sleepiness?

• Pitolisant (Wakix): histamine-3 receptor antagonist/inverse agonist; side effects—insomnia, nausea, anxiety.

• Solriamfetol (Sunosi): dopamine & norepinephrine reuptake inhibitor; contraindicated with MAOIs; monitor BP & HR.

FDA-approved medication for both excessive daytime sleepiness and cataplexy in patients ≥7 years old?

Sodium oxybate (Xyrem).

How does sodium oxybate help in narcolepsy?

restores normal sleep architecture at night, improving daytime alertness

Off-label medications for cataplexy?

certain SSRIs and TCA, which may suppress REM sleep paralysis

What is the most common breathing-related sleep disorder?

Obstructive sleep apnea hypopnea syndrome.

Which gender is more affected by obstructive sleep apnea hypopnea syndrome?

Men

What condition is strongly associated with obstructive sleep apnea?

obesity

What causes obstructive sleep apnea hypopnea syndrome?

repeated episodes of upper airway collapse and obstruction, leading to sleep fragmentation

Why can’t patients with obstructive sleep apnea sleep and breathe at the same time?

airway obstruction prevents breathing during sleep, causing repeated awakenings

What are the hallmark symptoms of obstructive sleep apnea?

loud disruptive snoring, witnessed apnea episodes, and excessive daytime sleepiness

How is obstructive sleep apnea diagnosed?

clinical evaluation and polysomnography

What is the primary treatment for obstructive sleep apnea?

Continuous positive airway pressure (CPAP) therapy.