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Section 8
Circadian Rythms and Sleep

Question 8 | Test | Table of Contents

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In the last section, we discussed combined stimulus control therapy and sleep restriction therapy, as well as  relaxation therapies and cognitive therapy. 

In this section, we will discuss circadian rhythms.  In addition to how circadian rhythms work, we will also discuss realigning circadian rhythms and altering circadian rhythms with light. 

♦ How Circadian Rhythms Work
First, let’s discuss how circadian rhythms work.  In one of our sessions, Samantha, a client experiencing insomnia asked me if getting enough sleep is all that counts. 

I responded, "No. Another important aspect of sleep is regularity. A regular schedule is essential to sleep for several reasons. First, we are creatures of habit. Daily routines regarding relationships, meal times, work schedules, and sleep helps provide peace of mind. But even more important, establishing a regular pattern reinforces the timing of the body’s internal biological clock. In addition to the cycles of sleep stages, another cycle also profoundly affects when we sleep and when we are awake. This cycle is the circadian rhythm.

"Your circadian rhythm, Samantha, is tied to the dependable cycle of night and day. You could also call it your ‘biological clock.’ Circadian rhythms span about 25.9 hours and helps to govern your daily cycle of sleep and wakefulness, body temperature, metabolic rate, and hormone release. Circadian rhythms are generated by your brain’s suprachiasmatic nucleus." 

Samantha suggested that the 25.9 hour circadian rhythm contradicted the 24 hour calendar day.  Samantha stated, "It seems like maybe our biological clocks are imperfect, anyway."  How would you have responded to Samantha?  I stated, "Although our circadian rhythms run slower than 24 hours, it is normally cued to the geophysical day so that biological functions can coincide with the varying lengths of daylight throughout the calendar year.  Therefore, these cues are primarily taken from light.  That’s why you feel sleepy at night and awake in the morning." 

Have you found that disruption of the circadian rhythm can result in sleep disruption or sleep
deprivation?  I have found that disrupted circadian rhythms can also perpetuate insomnia. 

♦ Realigning Circadian Rhythms
An effective method for Samantha to realign her circadian rhythms was to establish a regular rise time. As discussed in the last sections, rise time can be easier to manipulate than bedtime. As Samantha found, artificial means of waking can be effective. For Samantha, it became necessary to change her rise time on the weekends. Samantha stated, "I usually sleep until 7 through the week, but on the weekends I might sleep until noon or one." 

I responded, "Samantha, can I recommend that you establish a regular rise time that you can maintain every day of the week?"  Due to our previous discussion, Samantha saw the benefit of realigning her circadian rhythms by maintaining a regular sleep pattern. Samantha then strove to wake up at 7, or no later than 8, no matter what happened the night before. Though setting a rise time may seem inconsistent with earlier recommendations to determine sleep need and increase sleep time to meet that need, could your client benefit from realigning circadian rhythms? 

At a later session, Samantha complained, "I might be getting better sleep, but getting up at 7 on the weekends sucks!  I’m so used to sleeping in."  How would you have responded to Samantha?  I stated, "Consider the fact that by waking up at 7 instead of noon you are adding ten hours to weekend.  That’s more than a full day at the office!  Let me ask you, what have you been doing during those early weekend hours?" 

Samantha admitted that she was being more productive by clearing her desk of chores, so that by 10 a.m., she was ready to enjoy her day.  Do you have a client like Samantha?  Could he or she benefit from listening to this section to hear how realigning circadian rhythms worked for another client?

♦ Altering Circadian Rhythms with Light
In addition to how circadian rhythms work and realigning circadian rhythms, let’s discuss altering circadian rhythms with light.  It is possible to manipulate circadian rhythms by changing exposure to light at key times of the day. One study looked at people who experiencing delayed sleep phase syndrome, chronically falling asleep later than desired and awakening later than desired.  They were exposed to light treatment of 2500 lux for two hours every morning for one week.  Subsequently, these test subjects were able to fall asleep earlier and were more alert in the morning than a control group exposed to dim light. 

A good clinical example might be Ian, age 32. Ian worked a third shift job and therefore often didn’t go to sleep until 8 a.m. Ian stated, "I feel like all I do is work and sleep. I go to work at 9 p.m. and get off at 7 a.m.  It takes me half an hour to get home and I’m wide awake. I finally get tired enough to sleep at around noon. Then I sleep until around 7 or 8. If I get up any earlier I just feel exhausted." Ian was not suffering from insomnia because when he went to bed he fell asleep quickly and stayed asleep throughout the night. 

Ian had a case of delayed sleep phase syndrome.  Ian and I decided to alter his circadian rhythms using a bright light.  I loaned Ian a commercially available light box that he placed on a desk in his study. The box provided ten thousand lux of light when Ian was about fifteen inches from it.  I stated to Ian, "Consider rising earlier each afternoon and sit next to the light for a brief period.  Ian continued the treatment for about one week before noticing that he was starting to feel tired and sleepy earlier than noon. 

Ian stated, "I’m going to bed earlier and I’m actually starting to feel more alert before work."  With the use of the light therapy and careful sleep management, Ian successfully advanced his sleep period by three hours.  Ian started going to bed at 9 a.m. and getting up at 4:30 p.m.   Do you have a client who could benefit from altering circadian rhythms with light?

In this section, we have discussed circadian rhythms.  In addition to how circadian rhythms work, we will also discuss realigning circadian rhythms and altering circadian rhythms with light. 
                                                                             
In the next section, we will discuss delayed sleep phase syndrome.  Delayed sleep phase syndrome is a different type of circadian rhythm maladjustment.  Our discussion will focus on treating delayed sleep phase syndrome through a three step intervention called phase delay.  The three steps to phase delay are initial phase delays, subsequent phase delays, and maintaining the rhythm.
Reviewed 2023

Peer-Reviewed Journal Article References:
Asarnow, L. D., Soehner, A. M., & Harvey, A. G. (2014). Basic sleep and circadian science as building blocks for behavioral interventions: A translational approach for mood disorders. Behavioral Neuroscience, 128(3), 360–370.

Heller, H. C., Ruby, N. F., Rolls, A., Makam, M., & Colas, D. (2014). Adaptive and pathological inhibition of neuroplasticity associated with circadian rhythms and sleep. Behavioral Neuroscience, 128(3), 273–282.

Klein, S. B. (2019). The phenomenology of REM-sleep dreaming: The contributions of personal and perspectival ownership, subjective temporality, and episodic memory. Psychology of Consciousness: Theory, Research, and Practice, 6(1), 55–66.

Mathes, J., Weiger, N., Gieselmann, A., & Pietrowsky, R. (2019). The threat simulation in nightmares—Frequency and characteristics of dream threats in frequent nightmare dreamers. Dreaming, 29(4), 310–322.

Miller, K. E., Micol, R. L., Davis, J. L., Cranston, C. C., & Pruiksma, K. E. (2019). Predictors of treatment noninitiation, dropout, and response for cognitive behavioral therapy for trauma nightmares. Psychological Trauma: Theory, Research, Practice, and Policy, 11(1), 122–126.

Pontes, A. L. B. d., Engelberth, R. C. G. J., Nascimento, E. d. S., Jr., Cavalcante, J. C., Costa, M. S. M. d. O., Pinato, L., Toledo, C. A. B. d., & Cavalcante, J. d. S. (2010). Serotonin and circadian rhythms. Psychology & Neuroscience, 3(2), 217–228.

QUESTION 8
What are two ways to adjust circadian rhythms?
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