How Can Circadian Rhythm Problems Cause Insomnia?
The circadian rhythm is the body’s natural pattern of physiological and behavioral processes that are timed to a near 24-hour period. There are many processes included in this pattern, including sleep-wake cycles. It is under the control of the biological clock in the suprachiasmatic nuclei, which is in the part of your brain called the hypothalamus.
In some individuals, the circadian rhythm becomes disrupted and may not be synchronized properly to the natural day-night cycle. This phenomenon of being out of sync with external time cues may occur in total blindness, with shift work or jet lag, or due to shifts in the sleep phase. Having an urge to fall asleep earlier than normal is called advanced sleep phase syndrome. Wanting to fall asleep later than normal is called delayed sleep phase syndrome. These are collectively called circadian rhythm sleep disorders. The mismatch may lead to insomnia or excessive sleepiness at inappropriate times. In this situation, the treatment for the insomnia is unique.
Using Phototherapy to Treat Circadian Rhythm Insomnia
Exposure to bright light is called phototherapy, and it can be effective in shifting an abnormal circadian rhythm back into its proper phase. If you suffer from insomnia when you first go to bed but have a desire to sleep well into the morning, then being exposed to light upon awakening can shift your sleep period earlier.
The treatment consists of sitting in front of a light box that has a strength of 10,000 lux for 30 to 40 minutes upon awakening. Conversely, if you are falling asleep too early and wake before you desire to, the light box can be used in the evening.
In most cases, you will see the effect of phototherapy within two or three weeks. If it is effective, most people will require lifelong treatment.
Using Behavioral Therapy to Treat Circadian Rhythm Insomnia
Alternatively, certain behavioral therapies may be helpful in treating your insomnia if you have delayed sleep phase syndrome. One such treatment is called chronotherapy. It involves close monitoring of your sleep schedule, which may include use of a sleep log. Chronotherapy requires delaying the time that you go to sleep in order to shift the time that you feel sleepy. These shifts generally require you to delay sleep by two to three hours on successive days until the desired bedtime is achieved. Once this is accomplished, it must be strictly adhered to, which can be difficult.
Chesson, AJ, et al. "Practice parameters for the use of light therapy in the treatment of sleep disorders." Standards of Practice Committee, American Academy of Sleep Medicine. Sleep. 1999;22:641.
Czeisler, CA, et al. "Chronotherapy: resetting the circadian clocks of patients with delayed sleep phase insomnia." Sleep. 1981;4:1.