Handbook of Psychology

CHAPTER 14

Insomnia

CHARLES M. MORIN, JOSÉE SAVARD, MARIE-CHRISTINE OUELLET, AND MEAGAN DALEY

317

THE BASICS OF SLEEP 317
Biopsychosocial Determinants of Sleep 318
The Role of Sleep and the Consequences of
Sleep Deprivation 319
INSOMNIA: SCOPE OF THE PROBLEM 320
Prevalence 321
Correlates and Risk Factors 322
The Impact of Insomnia 324
EVALUATION OF SLEEP COMPLAINTS/DISORDERS 324
Clinical Interview 325
Sleep Diary Monitoring 326
Polysomnography 326
Self-Report Measures 327
Behavioral Assessment Devices 327

The Role of Psychological Evaluation 328

Evaluation of Daytime Sleepiness 328

TREATMENTS 328

Help-Seeking Determinants 329

Barriers to Treatment 329

Benefits and Limitations of Sleep Medications 329

Psychological Therapies 330

Summary of Outcome Evidence 332

Combined Psychological and Pharmacological

Treatments 333

CONCLUSIONS AND DIRECTIONS FOR

FUTURE RESEARCH 333

REFERENCES 334

Getting a good night•s sleep is very much dependent on good
psychological and physical health. Stress, anxiety, and de-
pression almost inevitably interfere with sleep, as do pain and
other medical problems. Chronic sleep disturbances can also
increase the risk for major depression and can lower immune
function. Conversely, sleep may play a protective role against
infectious diseases and may even speed up recovery from
some illnesses. These observations highlight the multiple
links between sleep and health and illustrate why sleep has
become a subject of great interest to both scientists and the
lay public. Sleep clinics are now present in most major med-
ical centers and there is a new behavioral sleep medicine
specialty currently emerging. This chapter is about sleep, and
more speci“cally about insomnia, which is the most preva-
lent of all sleep disorders and one of the most frequent health
complaints brought to the attention of health care practition-
ers. After presenting an overview of some basic facts about
sleep, the epidemiology of insomnia is summarized, includ-
ing its main correlates and risk factors, followed by a

description of validated assessment and treatment methods

for the clinical management of insomnia.

THE BASICS OF SLEEP

There are two types of sleep: nonrapid-eye-movement

(NREM) and rapid-eye-movement (REM). Brain activity in

NREM sleep, as measured by an electroencephalogram

(EEG), is subdivided into four distinct stages, simply labeled

stages 1, 2, 3, and 4. From a state of drowsiness, the individ-

ual slips into stage 1, then progresses sequentially through

the other stages of NREM sleep. Of short duration (about 5

minutes), stage 1 is a transitional phase between wakefulness

and more de“nite sleep. During this light sleep, the arousal

threshold is low, and the brain wave signal is characterized by

low-amplitude and high frequency waves. Progressively, the

amplitude of the signal increases and its frequency decreases

as the individual enters subsequent NREM stages. Stage 2

generally lasts 10 to 15 minutes and, for most people, corre-

sponds to the phenomenological experience of falling asleep

(Hauri & Olmstead, 1983). Stages 3 and 4 are considered the

deepest stages of sleep and together last between 20 to 40

minutes in the “rst sleep cycle. They are often referred to as

Preparation of this chapter was supported in part by grants from the
National Institute of Mental Health (MH55469) and by the Medical
Research Council of Canada (MT-14039).