Lying awake, late at night, reliving the negative events of the day and dreading the morning but wishing the night was over is one of the more difficult and yet fairly common experiences of life. This is the experience of insomnia.
Insomnia is the most commonly diagnosed sleep disorder. Approximately one out of three Americans reports having disturbed sleep and chronic insomnia affects 10% - 15% of the population. Insomnia can be acute or chronic and is variable in its presentation and effects. Although rarely the main reason for seeing a doctor, more than half the patients consulting a primary care physician have a complaint of insomnia of some kind. It is more frequent among women, people with chronic medical problems, people with psychiatric disorders and in older people. In 9 out of 10 cases, it occurs along with some other disorder, although it can be a primary condition without co-morbid conditions.
While being awake at night is a very unpleasant and difficult experience, it is the daytime symptoms which most impact on the lives of those suffering with insomnia. Common problems include fatigue, negative mood, problems with work, decreased quality of life, increased irritability, mood disturbance, decreased functioning and increased risk of depression. The impact of insomnia on the health and well being of insomniacs results in lost productivity and increased cost to society.
Insomnia is a disorder of arousal. Increased arousal, often related to fear of not sleeping or being unable to function effectively during the day, prevents the usual functioning of brain systems which initiate and maintain sleep. One way of thinking about insomnia is to consider whether the insomnia is a symptom associated with other problems or is a disorder that stands on its own. Primary insomnia is a disorder of arousal that lasts for one month or longer and results in significant distress or impairment. Co-morbid insomnia is insomnia associated with, but not necessarily caused by, other difficulties such as poor sleep habits, medications, medical problems or psychiatric conditions.
In the case of primary insomnia there is a state of hyperarousal and increased metabolic rate and elevated high-frequency EEG activity. It is often long standing, perhaps starting in childhood. Successful treatment consists of decreasing arousal and strengthening the sleep system so as to allow more natural sleep to occur. In the case of co-morbid insomnia, it may be sufficient to treat the co-morbid condition to relieve the arousal and restore normal sleep. An example of this would be improved sleep following the successful treatment of a pain problem which resulted in difficulty sleeping. It may also be necessary to treat both the insomnia and the co-morbid condition. In this example, even after successful treatment of the pain problem the insomnia may persist.
The most effective way we have of understanding insomnia is the three factor model proposed by Spielman. In this model there are predisposing factors (such as an easily aroused nervous system) which form the foundation for insomnia, precipitating factors (such as life stresses like the loss of a job) which cause the initial over arousal and insomnia, and perpetuating factors (such as maladaptive coping strategies and poor sleep habits) that maintain chronic insomnia. Treatment involves targeting the perpetuating factors which keep the insomnia going even if the initial stress has resolved.
Several aspects of insomnia are important to mention. People with insomnia tend to unknowingly over estimate the time it takes to fall asleep and underestimate the time they are asleep. In addition, state misperception can occur wherein the person is actually in a very light state of sleep but misperceives this as being awake. Addressing these issues is an important component of treating insomnia.
Treatment falls into two broad types, medication and cognitive behavior therapy. These may be used alone or in combination. The next two posts will discuss the treatment of insomnia with medication and with the use of cognitive behavior therapy. Some milder forms of insomnia may be successfully managed with a self help approach and two good books to consult are "No More Sleepless Nights" by Peter Hauri and Shirley Linde and "Say Good Night to Insomnia" by Gregg Jacobs.