Chapter 18-5: Insomnia

TEXTBOOK PRESENTATION

Patients with insomnia sometimes have trouble falling asleep, sometimes fall asleep easily but wake up during the night, and sometimes have both problems. The American Sleep Disorder Association defines insomnia as “a repeated difficulty with sleep initiation, duration, consolidation, or quality that occurs despite adequate time and opportunity for sleep and results in some form of daytime impairment and lasting for at least one month.”

DISEASE HIGHLIGHTS

1. Primary insomnia

   1. Pathogenesis is unknown but may be due to a state of hyperarousal.

   2. Prevalence of 2–4% in the adult population

2. Secondary (comorbid) insomnia

   1. Intrinsic sleep disorders

      1. OSA or central sleep apnea

      2. Restless leg syndrome/periodic limb movement disorder

   2. Extrinsic sleep disorders

      1. Psychophysiologic insomnia: due to conditioned arousal when in the bedroom

      2. Inadequate sleep hygiene or environmental sleep disorders (due to specific environmental elements)

      3. Related to alcohol or other substance use (stimulants, withdrawal from hypnotic drugs)

   3. Circadian rhythm sleep disorders

      1. Shift work disorder

      2. Delayed or advanced sleep phase syndrome (major sleep phase several hours later or earlier compared to conventional sleep times)

      3. Time zone change syndrome (jet lag)

   4. Related to medical conditions (chronic pain; nocturia; uncontrolled HF, chronic obstructive pulmonary disease/asthma, gastroesophageal reflux disease)

3. 35–50% of adults have insomnia symptoms; 12–20% have insomnia disorders

4. Risk factors for insomnia include the following:

   1. Depression

   2. Female sex

   3. Older age

   4. Lower socioeconomic status

   5. Concurrent medical and mental disorders

   6. Marital status (divorced/separated more often than married)

   7. Race (blacks more often than whites)

EVIDENCE-BASED DIAGNOSIS

1. Obtaining a thorough history helps establish the diagnosis of insomnia. Ask about predisposing, precipitating, and perpetuating factors. Initial screening questions include the following:

   1. Difficulty initiating sleep, staying asleep, or both?

   2. Early awakening?

   3. Nonrestorative sleep?

   4. Daytime consequences? (Lack of daytime fatigue or sleepiness suggests the insomnia is not clinically significant.)

   5. Frequency and duration?

2. Follow-up questions

   1. Precipitating events, progression, ameliorating or exacerbating factors?

   2. Sleep-wake schedule?

   3. Cognitive attitude toward sleep?

      1. Negative expectations regarding the ability to sleep and distortions about the effects of insomnia lead to perpetuation of the insomnia.

      2. Attitudes toward previous treatments are also important.

   4. Psychiatric disorder present?

   5. Substance misuse or medication use?

   6. Medical illness with nocturnal symptoms?

   7. Symptoms of sleep apnea, restless legs? (See discussion below.)

TREATMENT

1. CBT addresses dysfunctional beliefs and behaviors about sleep and is considered first-line treatment for all patients with insomnia. When compared to pharmacologic therapy, CBT has a similar effect but is better sustained. CBT includes the following components:

   1. Stimulus control

      1. Also known as sleep hygiene

      2. Based on premise that insomnia is a conditioned response to temporal and environmental cues

      3. Has been shown to be effective for sleep onset and maintenance

      4. Principles of sleep hygiene

         1. Go to bed only when sleepy.

         2. Use the bedroom only for sleep and sex, not reading, watching television, eating, working, or using a computer

         3. If unable to sleep after 20 minutes in bed, get out of bed, go into another room, ...