Sleep Disorders

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4.4
A Night’s Sleep
During a typical night, a sleeper goes
through this sequence of EEG stages. Notice that sleep is deepest during the first
part of the night and shallower later on,
when REM sleep becomes more prominent.
Awake
EEG sleep stages
FIGURE
Chapter 4 Consciousness
REM
1
REM
REM
REM
REM
2
3
4
1
2
3
4
5
6
7
Hours of sleep
Source: Cartwright (1978).
Sleep Disorders
psychology
applying
STIMULUS CONTROL
THERAPY Insomnia
can often be reduced
through a combination
of relaxation techniques and stimulus
control therapy, in which the person goes
to bed only when sleepy and gets out of
bed if sleep does not come within fifteen
to twenty minutes. The goal is to have
the bed become a stimulus associated
with sleeping, and perhaps sex, but not
with reading, eating, watching television,
worrying, or anything else that is incompatible with sleep (Edinger et al., 2001).
Sometime in life, most people experience sleep-related problems (Silber, 2001). These
can range from occasional nights of tossing and turning to the more serious and longterm sleep disorders that affect as many as 70 million people in the United States alone
(Institute of Medicine, 2006). The most common sleep disorder is insomnia, in which
people feel daytime fatigue due to trouble falling asleep or staying asleep. If you have
difficulty getting to sleep or staying asleep that persists for longer than one month at
a time, you may be suffering from insomnia. Besides being tiring, insomnia is tied to
mental distress and impairment of functioning. Insomnia is especially associated with
depressive and anxiety disorders (U.S. Surgeon General, 1999). Overall, insomniacs are
three times more likely to show a mental disorder than individuals with no sleep complaints (Ford & Kamerow, 1989; Ohayon & Roth, 2003). It is unclear from such correlations, however, whether insomnia causes mental disorders, mental disorders cause
insomnia, or some other factor causes both.
Sleeping pills can relieve insomnia. However, they may interact dangerously with
alcohol, may disturb REM sleep, and may eventually lead to increased sleeplessness
(Ashton, 1995; Poyares et al., 2004). In the long run, learning-based treatments may be
more helpful (Perlis et al., 2001; Stepanski & Perlis, 2000). These include the cognitive
behavior therapy methods described in the chapter on treatment of psychological disorders and progressive relaxation training techniques mentioned in the chapter on
health, stress, and coping. Both have been shown to promote better sleeping by reducing anxiety, tension, and other stress reactions (Bernstein, Borkovec, & Hazlett-Stevens,
2000; Jacobs et al., 2004). Short daytime naps and moderate evening exercise can also
help some people get to sleep more easily, sleep better, and experience better mood and
performance the next day (Tanaka et al., 2001).
Narcolepsy is a disturbing daytime sleep disorder that is typically first seen in people who are between fifteen and twenty-five years old (Dyken & Yamada, 2005; Zeman
et al., 2004). People with narcolepsy abruptly enter REM sleep directly from the waking state, usually as they are laughing or experiencing some other emotional state.
Because of the loss of muscle tone in REM, narcoleptics may experience cataplexy,
meaning that they collapse and remain briefly immobile even after awakening. The
most common cause of narcolepsy appears to be the absence or deficiency of a recently
discovered neurotransmitter called orexin, which is also known as hypocretin (Nishino &
Kanbayashi, 2005). A combination of regular naps and stimulant drugs can be a helpful
treatment (Rogers, Aldrich, & Lin, 2001; Schwartz, 2005).
Sleeping and Dreaming
SUDDEN INFANT DEATH SYNDROME
(SIDS) In SIDS cases, seemingly healthy
infants stop breathing while asleep in
their cribs. All the causes of SIDS are not
known, but health authorities now urge
parents to ensure that infants sleep on
their backs, as this baby demonstrates.
insomnia A sleep disorder in which a
person feels tired during the day because of trouble falling asleep or staying asleep at night.
narcolepsy A daytime sleep disorder
in which a person suddenly switches
from an active waking state into REM
sleep.
sleep apnea A sleep disorder in which
people briefly but repeatedly stop
breathing during the night.
sudden infant death syndrome (SIDS)
A disorder in which a sleeping baby
stops breathing but does not awaken
and dies.
sleepwalking A phenomenon that
starts primarily in non-REM sleep, especially in stage 4, and involves walking
while asleep.
nightmares Frightening dreams that
take place during REM sleep.
night terrors Horrific dream images
during stage 4 sleep, followed by a
rapid awakening and a state of intense
fear.
REM behavior disorder A sleep disorder in which the decreased muscle tone
normally seen in REM sleep does not
appear, thus allowing dreams to be
acted out.
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People who suffer from sleep apnea briefly stop breathing hundreds of times each
night, waking each time long enough to resume breathing. In the morning, victims do
not recall the awakenings. However, they feel tired and tend to suffer headaches,
reduced attention, and learning difficulties (Naëgelé et al., 1995). In one tragic case, two
members of a train crew—both of whom had apnea—fell asleep on the job, resulting
in a collision that killed two people (Pickler, 2002). Apnea has many causes, including
genetic predisposition, obesity, problems with brain mechanisms that control breathing, and compression of the windpipe (Kadotani et al., 2001; Macey et al., 2002;
Richards et al., 2002). Effective treatments include weight loss and use of a mask that
provides a steady stream of air (Ayas et al., 2006; Dixon, Schachter, & O’Brien, 2005;
Gupta & Reiter, 2004). In some cases surgery may be required to widen the air passageway in the upper throat (Friedman et al., 2003; Patel et al., 2003).
In cases of sudden infant death syndrome (SIDS), sleeping infants stop
breathing and die. SIDS is the most common cause of unexpected infant death in
Western countries (Daley, 2004). In the United States, it strikes about two of every
thousand infants, especially very-low-birth-weight babies, usually when they are two
to four months old (Smith & White, 2006; Vernacchio et al., 2003). Some SIDS cases
may stem from problems with brain systems that regulate breathing, from exposure
to cigarette smoke, or possibly from genetic causes (Anderson, Johnson, & Batal,
2005; Creery & Mikrogianakis, 2004). Correlational evidence suggests that about half
of apparent SIDS cases might actually be accidental suffocations caused when infants
sleep face down on a soft surface (Gilbert et al., 2005). In the United States, for
example, SIDS may be particularly common in families in which babies are placed
in the face-down position (Corwin et al., 2003; Hauck et al., 2002; Shields et al.,
2005). Observational evidence indicates that the danger of the face-down position
is especially great for babies who do not usually sleep in that position or who do
not sleep with a pacifier in their mouths (Li et al., 2006; Paluszynska, Harris, &
Thach, 2004). Since doctors began a “back to sleep” program, which advises parents
to be sure their babies sleep face up, the number of infants dying from SIDS in the
United States has dropped by 50 percent (Daley, 2004; Moon, Oden, & Grady, 2004;
Rasinski et al., 2003). Babies who sleep face up may also be less likely to inhale
potentially toxic bacteria that grow in some foam mattresses (Jenkins & Sherbum,
2005).
Sleepwalking occurs in non-REM sleep, usually in childhood (Guilleminault et al.,
2003; Masand, Popli, & Welburg, 1995). By morning, most sleepwalkers have forgotten their travels. Despite myths to the contrary, waking a sleepwalker is not harmful.
Drugs help, but most children simply outgrow the problem. One adult sleepwalker was
cured when his wife blew a whistle whenever he began a nighttime stroll (Meyer,
1975).
Nightmares are frightening REM dreams that occur in 4 to 8 percent of the general population but in a much higher percentage of people who suffer from posttraumatic stress disorder following military combat or rape (Kryger, Roth, & Dement, 2000;
Zadra & Donderi, 2000). Night terrors are horrific dream images during stage 4 sleep.
Sleepers often awaken from a night terror with a bloodcurdling scream and remain
intensely afraid for up to thirty minutes. Yet they may not recall the episode in the
morning. Night terrors are especially common in boys, but adults can suffer milder versions. The condition is sometimes treatable with drugs.
In REM behavior disorder, the near paralysis that normally accompanies REM sleep
does not occur, so sleepers move as if acting out their dreams (Abad & Guilleminault,
2004). If the dreams are violent, the disorder can be dangerous to the dreamer or those
nearby. One nine-year-old boy in New York City was seriously injured when he jumped
from a third-floor window while dreaming that his parents were being murdered. In
another case, a Minnesota man grabbed his wife’s throat while dreaming about breaking a deer’s neck (Brown, 2003). REM behavior disorder sometimes occurs along with
daytime narcolepsy (Schenck & Mahowald, 1992) and in one case was caused by a brain
tumor (Zambelis, Paparrigopoulos, & Soldatos, 2002). Fortunately, drug treatments are
usually effective (Takeuchi et al., 2001)