Sleep Centers of Middle Tennessee


Circadian Rhythm Disorders

Circadian rhythm disorders involve a disruption to the patient’s natural sleep-wake cycle. As part of this, sleep may occur at inappropriate times or quality of sleep may be disturbed. There are many different types of circadian rhythm disorders. One of the more common circadian rhythm disorders is shift work sleep disorder, which is characterized by an inability to initiate or maintain sleep, or poor quality sleep, as the result of shift work. Another fairly common circadian rhythm disorder is delayed sleep phase syndrome, which manifests itself by the sleep period occurring later than desired, or later than is compatible with the patient’s schedule. This occurs to such a degree that the ability to fulfill major obligations at work, home, or school is negatively impacted. Delayed sleep phase syndrome patients almost always describe themselves as “night owls”, and this disorder is frequently confused with insomnia. It should be noted that delayed sleep phase syndrome patients usually sleep normally once initiate sleep; however, waking at the desired time is frequently difficult. This circadian rhythm disorder occurs most often in the adolescent or early adult phases of development. Advanced sleep phase syndrome is at the opposite of the spectrum of delayed sleep phase syndrome in that the sleep period occurs earlier in the day than desired. This circadian rhythm disorder most often occurs in the older adult population. Other circadian rhythm disorders include jet lag (in which the circadian rhythm is disrupted as the result of travelling across time zones), irregular sleep wake rhythm (characterized by a sleep-wake rhythm that is so disorganized that there is no clear pattern), and free running/non-entrained rhythm (in which the sleep-wake rhythm is not entrained to respond to our normal circadian rhythm). Circadian rhythm disorders are usually treated using:

  1. Light therapy (since light is largely responsible for regulating our circadian rhythms),
  3. Melatonin (since this hormone, and the timing of its release into the system, impacts our circadian rhythm), and
  5. Behavioral interventions (such as maintaining adequate sleep hygiene).

Click here to make an appointment to discuss circadian rhythm disorders with a sleep doctor.