Circadian Rhythm Sleep Disorder DSM-5 307.45 (ICD-9-CM, Multiple Codes)
DSM-5 Category: Sleep Disorders
CRSD (Circadian Rhythm Sleep Disorder) is a DSM-5 (Diagnostic and Statistical Manual of mental Disorders, fifth edition) class of sleep disorders in which one’s internal sleep wake clock is disrupted, resulting in disturbed sleep and consequential daytime fatigue (American Psychiatric Association, 2013).
Our bodies run on a 24- hour cycle that regulates our behavioral and physiological functions, including our level of arousal, or sleep/wake cycle. The etymology of the word Circadian is the Latin circa, which means approximately, and diem, or day. Circadian rhythms run on a 23.5 to 24.5 hour cycle. Our circadian rhythms are regulated by external cues, such as availability of sunlight, but also are intrinsically hardwired into us, and regulated by the suprachiasmatic nuclei in the hypothalamus. Availability of light is the primary signal to the SCN (Huang, Ramsey, Marcheva, and Bass, 2011).
Circadian rhythms run synchronized to light, but light exposure at night does not have the same effect as exposure to light during the day. Early AM light exposure causes a phase shift, rewinding the circadian rhythm, but light exposure in mid-day produces no shift, or a very small shift. Light exposure around bedtime produces a phase delay, pushing the circadian rhythm ahead. Exposure to, or lack of light at critical points can disrupt the sleep/wake cycle. There is also a homeostatic process that accounts for one’s recent sleep-wake history, and will produce a stronger urge to sleep with longer periods of wakefulness. This system works together to produce sound sleep at night, and alert wakefulness during the day. If either process is disrupted, it can result in a sleep disorder. This is manifested as trying to sleep when the body wants to be awake, or trying to stay awake when the body is insisting on sleep. This results in fatigue, tension, reduced performance, and lowered alertness (Huang, Ramsey, Marcheva, and Bass, 2011).
CRSD are a class of sleep disorders in which there is a discrepancy between the desired time to go to sleep, maintain sleep, and awake. CRSD can lead to insomnia and daytime fatigue, and result in or contribute to medical problems, cognitive impairment, mood dysregulation, and interpersonal and occupational difficulties. People who have a circadian rhythm set to maximize energy and alertness at night are colloquially referred to as Night Owls. A Night Owl will have difficulty with punctuality at a job where they are expected to arrive at 7:00 AM. However, they will tend to do well at second or third shift work, as this is when Night Owls are at their best. A Night Owl in a relationship with a Lark, or someone who has maximum energy and alertness in the early morning, can experience difficulties as their schedules can be incompatible, and the Lark may look upon the Owl as lazy and unmotivated (The Cleveland Clinic Foundation, 2013).
Symptoms of Circadian Rhythm Sleep Disorder
According to the DSM-5, CRD is a sleep disorder characterized by a discrepancy between the internal setting of one’s circadian clock, and the sleep wake schedule required by one’s occupational/educational or social obligations. The sleep disruption leads to fatigue and/or insomnia. This disruption produces clinically significant distress, or impairs ones social, and or occupational/education functioning (American Psychiatric Association, 2013).
The DSM-5 lists several subtypes of CRSD:
- 307.45 (G47.21) Delayed sleep phase type: Delayed onset of sleep and poor maintenance of sleep, with an inability to fall asleep or wake at the desired time (American Psychiatric Association, 2013). This is more commonly seen in adolescents (Martinez, and Lenz, 2010). Other specifiers are: Familial: A family history of delayed onset of sleep. Overlapping with non-24-hour sleep-wake type circadian rhythm disorder.
- 307.45 (G47.22) Advanced sleep phase type: In which sleep onset and awakening times are advanced, and the patient is unable to stay awake or remain asleep until the desired time (American Psychiatric Association, 2013). This type is most often seen in the elderly (Martinez, and Lenz, 2010). This diagnosis is also accompanied by a familial specifier.
- 307.45 (G47.23) Irregular sleep-wake type: The sleep /wake cycle is disorganized, with variable sleep wake periods during a 24 hour period.
- 307.45 (G47.24) Non-24-hour sleep-wake type: A sleep wake cycle that is consistent with the 24-hour cycle, with a consistent dally drift of progressively later sleep onset and wake times.
- 307.45( G47.26) Shift work type: Insomnia secondary to shift work, and/or fatigue which can include falling asleep unintentionally.
- 307.45 (G47.20) Unspecified type: The sleep disturbance is related to the 24-hour circadian rhythm cycle, but the symptoms do not match the more specific diagnoses.
Other specifiers are:
- Episodic: Symptoms occur for at least one month, but less than three months.
- Persistent: Symptoms persist for three or more months.
- Recurrent: Two or more episodes occur within one year (American Psychiatric Association, 2013).
Risk Factors for Circadian Rhythm Sleep Disorder
The DSM-5 does not specify risk factors for the development of CRSD, but the diagnostic subtypes imply there is a genetic link. Having a first order relative with CRSD is a risk factor (American Psychiatric Association, 2013). It is also noted that poor sleep hygiene (e.g., texting or eating in bed, or an irregular bedtime) can contribute to CRSD. A flex-time work schedule, or working swing-shift can lead to CRSD, as can napping during the day, or sleeping past one’s usual rising time. Swing-shift work will prevent the body from adapting to a predictable cycle (Ju Kim, Lee, and Duffy, 2013).
Onset of Circadian Rhythm Sleep Disorder
The DSM-5 does not specify an age of onset for CRSD. As noted in the diagnostic criteria in the DSM-5, Advanced sleep phase type CRSD typically occurs in older adults. In teens and young adults, Delayed sleep phase type is more common (American Psychiatric Association, 2013).
Differential Diagnosis in Circadian Rhythm Sleep Disorder
The DSM-5 does not specify diagnostic rule-outs for CRSD (American Psychiatric Association, 2013).
A polysomnograph, or overnight sleep study, should be performed to properly diagnose the type and severity of the sleep disorder.
Comorbidity of Circadian Rhythm Sleep Disorder
Insufficient sleep and working against ones circadian rhythm is associated with long-term health problems, including metabolic syndrome and diabetes. Sleep restriction can decrease resting metabolic rate, and reduce pancreatic beta cell responsivity, leading to obesity, and risk of adult onset diabetes (Buxton, Cain, O’Connor, Porter, Duffy, Wang, Czeisler, and Shea, 2013). Reciprocally, people with diabetes tend to have sleep disorders, and there is a correlation between sleep deprivation and obesity (Sehgal, & Mignot, 2011).
Treatment of Circadian Rhythm Disorder
The DSM-5 does not specify treatments for CRSD (American Psychiatric Association, 2013). Treatment options indicated in others sources include:
1)Instruction in sleep hygiene: The patient can be educated in principles of sleep hygiene, such as avoiding caffeine and alcohol before bedtime, and keeping to a regular sleep/wake schedule. Specific sleep hygiene items to focus on in CRSD are:
For Delayed sleep phase - minimize HS (Hour of Sleep, or before bed) light exposure.
For Advanced, sleep phase- increase HS light exposure.
2) Bright Light Therapy: The patient is exposed to bright light (10,000 lux) to advance or delay sleep.
3) Chrono-therapy: progressive advancement or delay of sleep until an ideal schedule is reached. This requires a great deal of motivation and determination on the part of the patient (The Cleveland Clinic Foundation, 2013) as they will have to resist the urge to go to sleep, and overcome the desire to remain asleep.
4) Pharmacological Interventions: Short-term use of atypical non-benzodiazepine hypnotics are one option to induce sleep.
5) Lifestyle changes: e.g., leaving a third shift job for first or second shift.
Prognosis of Circadian Rhythm Sleep Disorder
The DSM-5 does not comment on the prognosis of CRSD (American Psychiatric Association, 2013). CRSD is very amenable to treatment, and generally, the prognosis is very good.
American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders. (5th Edition). Washington, DC.
Buxton, O.M, Cain, S.W., O’Connor, S.P., Porter, J.H., Duffy, J.F., Wang, W., Czeisler, C.A., and Shea, S.A. (2013). Metabolic Consequences in Humans of Prolonged Sleep Restriction Combined with Circadian Disruption. Science Translated to Medicine. 4(129): 129ra43. doi: 10.1126/scitranslmed.3003200. PMCID: PMC3678519. NIHMSID: NIHMS408028
Huang, W., Ramsey, K.M., Marcheva, B., and Bass, J. (2011). Circadian rhythms, sleep, and metabolism. Journal of Clinical Investigation. 21(6):2133–2141. doi: 10.1172/JCI46043.
Ju Kim, M, Lee, J.H., and Duffy, J.F. (2013). Circadian Rhythm Sleep Disorders. Journal of Clinical Outcomes and Management. 20(11): 513–528. PMCID: PMC4212693. NIHMSID: NIHMS580822
Martinez, D. and Lenz, M.C.S.L. (2010). Circadian rhythm sleep disorders. Indian Journal of Medical Research. 131,141-149.
Sehgal, A., and Mignot, E. (2011). Genetics of Sleep and Sleep Disorders. Cell.146, (2). 194–207. DOI: 10.1016/j.cell.2011.07.004
The Cleveland Clinic Foundation. (2013).Circadian Rhythm Disorders. Retrieved November 6, 2014, from http://my.clevelandclinic.org/services/neurological_institute/sleep-disorders-center/disorders-conditions/hic-circadian-rhythm-disorders
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