Circadian Rhythm Sleep Disorders

Circadian rhythm sleep-wake disorders (CRSDs) occur when the body’s internal biological clock is out of sync with the external environment or a required social schedule. This internal clock, located in the brain, regulates 24-hour cycles in hormone production, body temperature, and alertness. When these rhythms are disrupted, it results in insomnia, excessive daytime sleepiness, and impaired physical or mental functioning.

Types of Disorders

• Delayed Sleep-Wake Phase: Sleep and wake times are several hours later than the societal norm. This is frequently seen in teenagers and young adults.
• Advanced Sleep-Wake Phase: Falling asleep and waking up several hours earlier than desired. This is more prevalent in older populations.
• Non-24-Hour Sleep-Wake Rhythm: The internal clock follows a cycle longer than 24 hours, causing sleep times to shift later every day. This most commonly affects individuals who are totally blind and lack light-based cues.
• Shift Work Disorder: Chronic sleep loss and synchronization issues caused by work schedules that overlap with natural sleep times.
• Irregular Sleep-Wake Rhythm: Fragmented sleep patterns consisting of several naps throughout a 24-hour period rather than one consolidated block of sleep.
• Jet Lag Disorder: Occurs when traveling rapidly across multiple time zones. The internal clock remains synchronized to the departure point rather than the destination. Eastward travel (requiring an earlier bedtime) is typically more difficult to adjust to than westward travel.

Treatment Options

Diagnosis usually requires daily tracking of sleep and mapping the current cycle. Treatment focuses on resetting the clock and can involve strategic use of light therapy and melatonin, chronotherapy, and sleep hygiene; treatment necessity is determined by the degree of conflict between a person’s biological clock and their social or professional obligations. Management is highly individualized, focusing on whether the rhythm causes functional impairment or health risks rather than adhering to a universal schedule. Attempting to force a “standard” 9-to-5 schedule on someone with a significant biological rhythm disorder without proper clinical guidance can lead to persistent insomnia, increased risk of depression and anxiety, increased reliance on sedatives or stimulants.

Daylight Saving Time (DST) and standard time have a direct impact on circadian rhythm disorders, as they essentially impose a circadian shift on the entire population. Seasonal time changes disconnect our “social clock” from the “solar clock” (the natural light-dark cycle). This is particularly difficult for individuals with existing circadian disorders because their internal rhythms are already fragile or misaligned.

• “Springing Forward” involves losing an hour of sleep and shifting sunrise later in the morning is the most disruptive. For those with Delayed Sleep Phase Disorder, this change makes it even harder to wake up for work or school, often exacerbating chronic sleep debt.
• “Falling Back” involves gaining an hour which may seem beneficial, but it can cause “early morning awakening” for those with Advanced Sleep Phase Disorder, causing them to wake up even earlier than their already premature schedule.

Major medical organizations including the American Academy of Sleep Medicine (AASM) and the Society for Research on Biological Rhythms (SRBR) advocate for the abolition of seasonal time changes in favor of permanent standard time. Standard time is considered the most “natural” because it aligns the sun’s highest point with noon, providing more light in the morning. This morning light is the primary cue the brain uses to reset the circadian clock daily.

Resources and Foundations

Very professional office with excellent, well trained, pleasant and caring staff. Dr. Popper is very thorough, efficient, and caring. He explained what all his findings meant and answered all my questions to my satisfaction. Being a retired professional, I am very critical of doctors’ offices. Having been elsewhere before and displeased, I found the comparison amazing. Definitely worth the 30 mile drive from Van Nuys. Dr. Popper and Staff get a 5 out of 5 Star rating from me!”

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