Cognitive interventions to improve sleep

Insomnia is defined subjectively, and that’s important because often when people can’t sleep they get referred for an overnight sleep study, says R. Robert Auger, MD, Mayo Center for Sleep Medicine.

“Unless they are looking for other diagnoses such as sleep apnea, an overnight sleep test is not sophisticated enough or not designed to address insomnia in isolation.”

Insomnia is defined as having difficulty initiating or maintaining sleep or can be defined as nonrestorative sleep. The other requirement is that there’s decreased functioning during wakefulness. It is different from sleepiness that results from poor sleep hygiene when a person chooses to limit sleep. Insomnia is usually determined when a patient has had the issues for a month or longer. With insomnia, the sleep opportunity is adequate and sleep ability is reduced; with sleep deprivation, the sleep opportunity is reduced and sleep ability is adequate, Auger says.

Consequences of insomnia include fatigue /lethargy, cognitive impairment, physical complaints, occupational performance and depression.

It is also closely connected with quality of life, Auger said. He cited a 2002 study that compared three chronic conditions—severe insomnia, depression and congestive heart failure (CHF). Across the eight domains measured in terms of quality of life, severe insomnia registered on par with CHF and depression.

The prevalence of insomnia depends on how you define it. “When you talk about someone who’s had insomnia any time, it’s close to 50%. If you add the qualifier of daytime consequences, it goes down a bit. A good number to remember is 10% of people have chronic insomnia with the technical definitions. It can increase with increasing age, it’s more prominent in women than in men, it’s more common among those with lower economic status and multiple health problems,” Auger said.

The importance in treating insomnia is evident in these statistics, Auger said:

--Data indicate that untreated insomnia persists more than two years in more than 50% of patients

--Suicide is more likely among those who experience insomnia and depression

--Poorer subjective and objective sleep quality may be predictive of response to antidepressant therapy in elderly depressed patients.

Many pharmacological and behavioral treatments are available to treat insomnia. Among the drugs found effective are zolpidem (Ambien) and zopiclone. Behavioral models have also been found to be effective. Auger described three models:

--Sleep Restriction Therapy: Reduce time in bed to patient’s estimated total sleep time (minimum five hours). When average sleep efficiency over five consecutive days is at least 90%, time in bed can be extended by 15 minutes.

--Stimulus control therapy:Patient goes to bed only when sleepy and uses the bedroom only for sleeping or sex. Patient goes to another room when unable to sleep in 15 minutes, returning to bed only when sleepy.

-- Sleep hygiene education: Teaching patients about how sleep is affected by pets, snoring partners, TV, bedroom temperature, use of alcohol, nicotine and caffeine, fixation on the bedside clock, lack of exercise, or exercise too close to bedtime.

Though much is known about what works for patients dealing with insomnia, many areas need much more study. One is in how insomnia relates to depression.

“Insomnia has a special relationship to depression,” Auger said. “About a dozen studies show that if you have a patient with insomnia and follow them for a year or longer, their risk for developing major depression as compared to someone who doesn’t have insomnia is markedly higher. There’s definitely a relationship between insomnia and depression that we don’t quite understand.”