Chapter 8 - Sleep Disorders.pdf

 Two major types of sleep disorders: Dyssomnias  Difficulties in amount, quality, or timing of sleep Parasomnias  Abnormal behavioral and physiological events during sleep  Most deep sleep (N3) occurs early 80% of sleep is this slow-wave sleep (SWS)  SWS Critically Important! Strong evidence th...

 Two major types of sleep disorders: Dyssomnias  Difficulties in amount, quality, or timing of sleep Parasomnias  Abnormal behavioral and physiological events during sleep  Most deep sleep (N3) occurs early 80% of sleep is this slow-wave sleep (SWS)  SWS Critically Important! Strong evidence that deep sleep is important for the consolidation of memories, with recent experiences being transferred to long-term storage. This doesn’t happen indiscriminately though – a clear- out of the less relevant experiences of the preceding day also appears to take place.  A 2017 study revealed synapses shrink during sleep, resulting in the weakest connections being pruned away and those experiences forgotten  The cyclic nature of sleep is reliable:  REM periods every 90 – 120 minutes First REM period is shortest Most REM occurs late  Dreaming: Accounts for 20% of our sleeping time Length of dreams can vary from a few seconds to closer to an hour. Dreams tend to last longer as the night progresses and most are quickly or immediately forgotten. During REM sleep, the brain is highly active, while the body’s muscles are paralyzed and heart rate increases, and breathing can become erratic.  Dreaming is also thought to play some role in learning and memory: After new experiences we tend to dream more But it doesn’t seem crucial either: case of a 33-year-old man who had little or no REM sleep due to a shrapnel injury in his brainstem -- no significant memory problems   8 hours is often quoted, but the optimum sleeping time varies between people and at different times of life In a comprehensive review, in which 18 experts sifted through 320 existing research articles, the US National Sleep Foundation concluded that the ideal amount to sleep is 7-9 hours for adults, and 8-10 hours for teenagers Younger children require much more, with newborn babies needing up to 17 hours each day (not always aligned with the parental sleep cycle!)  However, quality of sleep matters, as does SWS v REM Some people may survive on less sleep because they sleep well Below 7 hours/night: compelling evidence for negative impacts on health  Too much sleep is also bad, but relatively few people appear to be afflicted by this problem  Newborns (0-3 months): 14-17 hours each day.  Infants (4-11 months): 12-15 hours each day.  Toddlers (1-2 years): 11-14 hours each day.  Preschoolers (3-5): 10-13 hours each day.  School age children (6-13): 9-11 hours per day.  Teenagers (14-17): 8-10 hours each day.  Younger adults (18-25): 7-9 hours each day.  Adults (26-64): 7-9 hours each day.  Older adults (65+): 7-8 hours each day.  Sleep deprivation affects all aspects of daily functioning – energy, mood, memory, concentration, attention Just a few hours of sleep deprivation decreases immune functioning 2017 review of 28 studies: night-shift workers were 29% more likely to develop obesity or become overweight than rotating shift workers Findings based on more than 2 million individuals: working night shifts raised the risk of a heart attack or stroke by 41%  Sleep loss may bring on feelings of depression in nondepressed individuals Paradoxically, can have antidepressant effects in depressed individuals  Teenagers are among the most sleep-deprived people on earth 2015 study: sample of 27,939 suburban high school students in Virginia:  Only 3% of students reported recommended amount of sleep for age (9 hrs)  20% indicated that they got < 5 hours; avg = 6.5 hours every weekday night After controlling for background variables (family status, income), each hour of lost sleep was associated with:     38% increase in the odds of feeling sad and hopeless 42% increase in considering suicide 58% increase in suicide attempts 23% increase in substance abuse  Teenagers are among the most sleep-deprived people on earth  Puberty: circadian clocks shift by a couple of hours: They get tired later at night than before and wake up later in the morning than they used to Sending a teenager to bed earlier won’t necessarily mean they fall asleep earlier This shift reverses at adulthood  Thus, teens are missing out on both restorative sleep and REM sleep, especially cycles that normally happen just before a person wakes up Restorative sleep helps to repair the body after a hard day; improves immune function and other biological processes REM sleep solidifies events and learning into memories  Relevance to school start times? Despite decades of research, thousands of publications and clear science, schools in only a few states (MN, IA, SC) and the DC have pushed their start times to 8:30 A.M. on average (a better time would be closer to 9 AM) Understanding Sleep Disturbances  31% of young adults sleep less than 6 hrs/night 69% report insufficient sleep   Partly genetic – feeling sleepy is partly due to hormonal processes Chronic sleep problems mostly due to POOR SLEEP HYGIENE Fall asleep faster when we exercise and have regular mealtimes Schedule changes of any kind disrupt sleep  Regular sleep schedules predict higher GPA and better mood   BLUE LIGHT We have photoreceptors in the eye that only respond to changes in light and dark, which are used exclusively to regulate circadian rhythms Melanopsin receptors; not specialized for visual functioning Sensitive to wavelengths in the 484-500 nm (blue light) They work even in the blind Tells us about how the environment is changing (light to dark)  We are surrounded by blue light! Computers, phone screens, e-readers, TV Our circadian systems interpret these as daylight and our sleep is postponed Research: those assigned to read an ebook before bed released less melatonin and were less sleepy; less alert the next AM  Two major types of sleep disorders: Dyssomnias  Difficulties in amount, quality, or timing of sleep Insomnia Disorder Hypersomnolence Disorder Narcolepsy Obstructive Sleep Apnea Hypopnea  Central Sleep Apnea  Sleep-Related Hypoventilation  Circadian Rhythm Sleep-Wake Disorders     Parasomnias  Abnormal behavioral and physiological events during sleep  Non-Rapid Eye Movement Sleep Arousal Disorder  Nightmare Disorder  Non-Rapid Eye Movement Sleep Behavior Disorder  Restless Legs Syndrome  Substance/Medication Induced Sleep Disorder  Insomnia disorder One of the most common sleep disorders Problems initiating/maintaining sleep  e.g., trouble falling asleep, waking during night, waking too early in the morning 35% of adults report daytime sleepiness Only diagnosed as a sleep disorder if it is not better explained by a different condition (e.g., GAD)  Microsleeps  Most last around 3 sec. – the amount of time it takes to drive the length of a football field! Facts and statistics – Approx. 6-10% prevalence rate; 25% in elderly – 30% of adults report insomnia symptoms – Often associated with medical and/or psychological conditions – 75-90% of pts. w/ insomnia have medical conditions, such as illnesses causing hypoxemia and dyspnea, gastroesophageal reflux disease, pain conditions, and neurodegenerative diseases – 40% of pts. w/ insomnia have comorbid psychological disorders (esp. depression) – Affects women twice as often as men Associated features – Unrealistic expectations about sleep – Believe lack of sleep will be more disruptive than it usually is  Hypersomnolence Disorder Sleeping too much or excessive sleep  May manifest as long nights of sleep or frequent napping Experience excessive sleepiness as a problem  Facts and statistics Often associated with medical and/or psychological conditions Only diagnosed if other conditions don’t adequately explain hypersomnia, which should be the primary complaint  Associated features Complain of sleepiness throughout the day Able to sleep through the night  Narcolepsy Principal symptom: Recurrent intense need for sleep, lapses into sleep or napping Also accompanied by at least one:  Cataplexy  Hypocretin deficiency  Going into REM sleep abnormally fast ( times/hr of sleep), but respiratory system works (2) Central sleep apnea (CSA)  Respiratory systems stops for brief periods (3) Sleep-related hypoventilation  Decreased breathing during sleep not better explained by another sleep disorder  Facts and statistics Sleep apneas occur in 10-20% of population More common in males Associated with overweight/obesity and increasing age  Associated features Persons are usually minimally aware of apnea problem Often snore, sweat during sleep, wake frequently May have morning headaches May experience episodes of falling asleep during the day (due to poor sleep quality at night)  Disturbed sleep (e.g., either insomnia or excessive sleepiness) leading to distress and/or functional impairment (e.g., decreased work productivity) Due to brain’s inability to synchronize day and night  Nature of circadian rhythms and body’s biological clock Circadian rhythms – our brain and bodies follow a 24-hour clock that is closely linked to the day-night cycle Suprachiasmatic nucleus:  Brain’s biological clock, governed by a specific gene, stimulates melatonin when it gets dark  Examples disorders of circadian rhythm sleep-wake Shift work type – job leads to irregular hours Familial type – associated with family history of dysregulated rhythms  Insomnia Benzodiazepines, nonbenzodiazepines (e.g., Ambien/zolpidem), and over-the-counter sleep medications Prolonged use  Can cause rebound insomnia, dependence Best as short-term solution if CBT ineffective  Hypersomnia and narcolepsy Stimulants (i.e., Ritalin) Cataplexy usually treated with antidepressants Breathing-related sleep disorders – May include medications, weight loss, or mechanical devices Circadian rhythm sleep-wake disorders – Phase delays Moving bedtime later (best approach) – Phase advances Moving bedtime earlier (more difficult) – Use of very bright light Trick the brain’s biological clock Cognitive behavioral therapy for insomnia (CBT-I) - Psychoeducation about sleep - Changing beliefs about sleep - Extensive monitoring using sleep diary - Practicing better sleep-related habits - Stimulus Control - Relaxation Nature of parasomnias – The problem is not with sleep itself – Problem is abnormal events during sleep, or shortly after waking Two classes of parasomnias – Those that occur during REM (i.e., dream) sleep – Those that occur during non-REM (i.e., non-dream) sleep New to DSM-5 Recurrent episodes of either/or: – Sleep terrors Recurrent episodes of paniclike symptoms during nonREM sleep – Sleepwalking Individual has no memory of the episodes  Facts and associated features More common in children (~6%) than adults (~1%) Person cannot be easily awakened during the episode, which lasts 30 sec – 3 mins Child has little memory of it the next day  Treatment – a wait-and-see posture Scheduled awakenings prior to the sleep terror Severe cases:  Antidepressants (i.e., imipramine) or benzodiazepines  Sleep walking disorder – somnambulism Occurs during non-REM sleep Usually during first few hours of deep sleep Person must leave the bed  Facts and associated features Problem is more common in children (6-17%) than adults (2.5%) Person is generally docile; complete amnesia Problem usually resolves on its own without treatment Seems to run in families May be accompanied by nocturnal eating  Repeated episodes of extended, extremely dysphoric dreams leading to distress and/or impairment in daily life  Not adequately explained by other conditions  Facts and associated features 10%-50% of children and 1% of adults have nightmares Occurs during REM sleep Dreams often awaken the sleeper Problem is more common in children than adults  Treatment May involve antidepressants and/or relaxation training   New diagnosis in DSM-5 Repeated episodes of arousal during sleep associated with vocalization and/or complex motor behaviors “acting out dreams” Click here for brief overview  Causes impairment or distress Often, major problem is injury to self or sleeping partner