Sleep Disorders

Glossary

"The golden chain that ties health and our bodies together" - Thomas Dekker

Free Running Circadian Disorder

Absent cues from the environment, everyone’s circadian rythym falls out of place. The brains suprachiasmatic nucleus keeps the body clock, but in most people it is synchronized to the light of the day. Some people seem to not respond to this synchronization. Their internal clock becomes detached from nature’s and from most of human society’s. This condition is called free-running disorder. Also called non-entrained sleeping, free-running disorder often results in a steady drift of wake-up and sleep times. Over time the patient is far out of the social norms for waking time, which can interfere with their lives.

Because they do not get light cues that most of us get, blind people are prone to free running disorder. It is estimated that over half of blind people have it. Sighted people can receive signals from the sunlight and their bodies adjust to natural daylight – sunrise and sunset.

The patient with free-running disorder often complains about insomnia and daytime sleepiness when he or she tries to conform to conventional sleep times. Teasing out non-entrained sleep patterns is not straightforward and may require some time and detective work. Actigraphy and sleep logs can help diagnose free-running disorder.

Is free-running disorder just an exaggerated version of advanced sleep-phase disorder or delayed sleep-phase disorder? It could be classified that way. The definitions of many sleep disorders overlap and there is always some subjective judgment in diagnosis. But the major sleep organizations do recognize free-running disorder as a separate category.

Treatment for free running disorder is often behavioral. This means reminding patients to go to sleep and to get up at specified times, and building cue into their day that they will notice with their conscious brains even if their internal clock doesn’t respond to those cues. Long periods of time outdoors during the day may help, as can phototherapy.

This is a disorder where melatonin is often the recommended drug therapy, especially for blind people. A larger dose (say 10 mg) is given to help the patient get back on track and a maintenance dose of 0.5 mg/day is prescribed to keep the circadian cycle on target. With the recent introduction of the melatonin agonist ramelteon, some doctors may prefer to use this medication instead, which has the advantage of being available in pharmaceutical grade purity and in measured doses, unlike health store melatonin which is not subject to as strict controls and likely to vary in quality and dosage.