Author: Ron Cridland, MD
Insomnia is a symptom of poor sleep quality. It is not a diagnosis by itself. Typically, insomnia may consist of difficulty falling asleep, difficulty staying asleep or difficulty returning to sleep. It may be of recent onset or “acute”. It may be of longstanding duration. When insomnia has existed for longer than 6 months, it is considered “chronic”. There are many causes of insomnia. Thus it is important to have a reasonable working diagnosis of what kind of insomnia you have before you can expect treatment to be effective.
Insomnia can be caused by pain, hot flashes and other underlying medical conditions such as asthma or allergies. Various medications can disturb sleep such as non-sedating antidepressants (eg: Welbutrin, Prozac), stimulants (eg: Ritalin, Dexedrine), prednisone, and beta-blockers (eg: metoprolol). Most psychiatric conditions including anxiety, depression, PTSD, OCD are associated with significantly disturbed sleep. Often underlying insomnia is a trigger for these conditions and becomes worse as the psychiatric condition develops.
Sometimes symptoms of “insomnia” consisting of disturbed and non-restorative sleep are the presenting symptom of another underlying sleep disorder such as Obstructive Sleep Apnea or Periodic Limb Movement Disorder. A sleep study or nocturnal polysomnogram is required to evaluate the sleep and determine if there is an underlying sleep disorder.
Circadian rhythm disorders usually present with insomnia. People with Delayed Sleep Phase Syndrome have a delayed biological clock. They may be considered “night owls” and like to stay up late and sleep-in late. When they try to go to sleep at an earlier and more conventional time, they have trouble falling asleep. “Larks” or people with Advanced Sleep Phase Syndrome want to go to sleep early and wake up early. When they wake up too early they have trouble returning to sleep.
People with Restless Legs Syndrome have great difficulty falling asleep because they cannot get their legs comfortable or keep them still. They are constantly moving around in bed and often have to get up and walk around before they can return to bed and fall asleep.
Some people are excessively sleepy during the day because of an underlying sleep disorder. Consequently they are often falling asleep during the day. Napping during the day can sometimes make it harder to fall asleep at night.
One of the most common causes of insomnia is Psychophysiological Insomnia or “conditioned insomnia”. As the name implies there are “psychological” and “physiological” factors contributing to this insomnia. The physiological factors are often obvious like pain, hot flashes or restless legs. Sometimes they are not so obvious like an underlying sleep disorder such as Obstructive Sleep Apnea or Periodic Limb Movement Disorder. A sleep study called a Nocturnal Polysomnogram is required to evaluate for underlying sleep disorders contributing to the sleep disturbance.
If you are tired and have to push yourself through your day and are living on “adrenaline”, by the end of the day, you have what I call an “adrenaline hangover”. Your body is physiologically stimulated and not able to fall asleep easily. Even when you fall asleep your body may still be in “fight-or-flight” mode, making your sleep very light and disturbed.
The psychological component of Psychophysiological Insomnia is primarily due to “conditioning”. If you go through a period of time in your life when your sleep is significantly disturbed, you may become conditioned to sleep that way. Some people get into the habit of thinking, worrying, planning or problem solving in bed. Consequently they learn to associate the bed with those mental activities and not sleeping. The classic example of conditioned insomnia is that of a young mother who immediately learns to sleep with “one ear open” when her first baby is born. When her babies are old enough to leave home, the mother is typically still vigilant when she sleeps because of the years of "listening" for her children during the night.
The good news is that no matter what was the cause of your conditioned insomnia, once we understand what we are dealing with we know how to change conditioning and recondition good sleep again. For information on resolving insomnia, go to the section on Insomnia Therapies.