(1) Circadian rhythm

Regulate your circadian rhythm

There is a “biological clock” in the brain that regulates alertness levels over a 24-hour cycle. This is called our “circadian rhythm.” When it is working well, our alertness level follows the pattern depicted by the upward arrows in the diagram below. The squiggly line is the likelihood that we will be able to stay awake or remain asleep.

Our circadian rhythm is influenced by our sleep-wake schedule and exposure to light. It can become dysregulated by the following:

• • An irregular sleep-wake schedule.

  • Too much light exposure in the evening and at night.

  • Too little light exposure during the day.

If your circadian rhythm become dysregulated, you will be less alert during the day, and you will be too alert when you want to sleep. To regulate your circadian rhythm do the following:

• • Maintain a regular bedtime and rise time every day of the week. 

  • Limit light exposure in the evening and at night.

  • Get plenty of light exposure during the day, especially soon after awakening. 

  • Some people may benefit from taking timed low-dose melatonin (see below). This is particularly true for people who have “night-owl” or early-bird” tendencies that make it difficult to maintain a regular sleep-wake schedule. These tendencies can result in Circadian Rhythm Sleep-Wake Disorders (follow the link for more information about these disorders and effective treatments).

Regulating your circadian rhythm with systematic sleep scheduling

When people are experiencing chronic insomnia, simply maintaining a regular sleep schedule may not be enough to restore normal sleep patterns. It may be necessary to use systematic sleep scheduling (see Strategy 9) which involves maintaining the same rise time, but delaying bedtime according to a schedule. This technique helps people to fall asleep quicker and stay asleep longer.  

Methods for reducing light exposure before bedtime and at night

Exposure to light (specifically light in the blue portion of the spectrum) suppresses your brain’s production of melatonin. Melatonin helps to regulate your biological clock. If you are exposed to light before bedtime or at night, it can dysregulate your biological clock and keep your alertness levels higher than you want them to be. To keep this from happening, keep lights dim and use black out curtains in your bedroom. Consider using special amber-colored glasses, and/or installing software on your computer, tablet, or/and phone, or using settings built into your phone.

• • Glasses that block 100% of blue light have a special coating and are either amber or red in color. Clear glasses block under 30%and are not sufficient to prevent the suppression of endogenous melatonin. Such glasses may be available from the Corvallis Clinic Sleep Medicine Department on the 2nd floor of the Asbury Building (call to inquire at: 541-754-1268). They can also be obtained online. Recommended models include: Uvex Skyper or Uvex S0360X (for wearing over eyeglasses). 

  • Software can be installed on electronic devices to limit blue light output. F.lux (https://justgetflux.com) is a free program for Windows, Mac, Linux, iPhone, and iPad. Twilight (http://twilight.urbandroid.org) is a free program for Android. On the iPhone, you can use the “Night Shift” setting (Go to Settings > Display & Brightness > Night Shift). 

• If you use a night light, use an amber-colored one (see example).

  • If you use a flashlight, an amber-colored one is optimal (see example). 

How to get enough light during the day

Your biological clock benefits from getting light exposure during the day, and particularly soon after you awaken. If it is hard for you to get natural light, specially designed therapy lamps and/or dawn simulators can be used. For more information, see: https://cet.org.

How to use melatonin properly

Over-the-counter melatonin supplements can be taken to add to the melatonin your brain makes. To use melatonin supplements properly do the following:

• • Obtain low-dose melatonin (300 microgram tablets are recommended). This is available at the Corvallis Clinic Pharmacy and online (see example). 

  • Consistently take 300mcg at 5 hours before bedtime and take 600mcg at bedtime every night for at least 90 days, and do not expect immediate results. 

  • Do not take large doses of melatonin (e.g., >1mg) or take melatonin on an irregular basis. This may dysregulate your biological clock.

A melatonin alternative: An alternative to the instructions above is to obtain a product called REMfresh. This is a relatively new product that has been specially formulated to mimic the body’s natural release of melatonin. It is most likely only available online. It comes in a 2mg dose that releases over a 7 hour period. The instructions are to take it 30-90 minutes prior to your scheduled bedtime. 

Continue to Strategy 2: Sleep drive (Build enough sleep drive to sleep)

For more information

To learn more about circadian rhythms see the following pages on the website How Sleep Works: The Two Process Model of Sleep Regulation and Circadian Rhythms.

To learn more about the role of light in the regulation of circadian rhythms visit the Center for Environmental Therapeutics.