Advanced Sleep-Wake Phase Disorder

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What is Advanced Sleep-Wake Phase Disorder?

As the saying goes, “early to bed and early to rise” leads to health, wealth, and wisdom. In reality, excessively early bedtimes may signal a sleep disorder called advanced sleep-wake phase disorder.

Advanced sleep-wake phase disorder (also called advanced sleep-phase syndrome) involves a shift in the circadian rhythm that leads to early bedtimes and arousals. People with advanced sleep-wake phase disorder experience a strong, sometimes irresistible urge to fall asleep in the evening, generally between 6 p.m. and 9 p.m., and wake too early in the morning, generally between 2 a.m. and 5 a.m.

These disrupted circadian patterns lead to fatigue, which makes staying awake until bedtime more difficult. In some cases, people with this disorder may fall asleep while driving or eating dinner. This leads some doctors to confuse advanced sleep-wake phase disorder for narcolepsy, which also involves falling asleep spontaneously during the day.

Symptoms of Advanced Sleep-Wake Phase Disorder

People with advanced sleep-wake phase disorder experience:

  • Irresistible urge to sleep in the early afternoon and evening
  • Consistent arousals in the early morning and an inability to return to sleep after awakening
  • Falling asleep during passive activities in evening, such as reading or eating
  • More rarely, falling asleep during active pursuits like driving or exercising
  • Feeling alert and refreshed upon awakening
  • Disrupted sleep patterns not explained by another sleep disorder, such as sleep apnea or narcolepsy

How Common is Advanced Sleep-Wake Phase Disorder?

Though many people may experience brief bouts of early bedtimes and early arousals following travel or illness, those episodes are usually brief and resolve without medical intervention. Chronic sleep-wake phase disorder rare, affecting only around 1 percent of adults. Older adults are more likely to experience this disorder.

What Causes Advanced Sleep-Wake Phase Disorder?

Like other circadian rhythm sleep-wake disorders, advanced sleep-wake phase disorder is a neurological disorder with no known cause. Because advanced sleep-wake phase disorder is more common in older adults, researchers believe that age-related changes to hormone levels are involved.


To diagnose advanced sleep-wake phase disorder, physicians use medical history, sleep patterns and self-reported symptoms. Polysomnography helps determine whether another sleep disorder, like narcolepsy or obstructive sleep apnea, might play a role.


Advanced sleep-wake phase disorder is treated with a “progressive phase delay.” This treatment uses light therapy and behavioral changes to help people maintain alertness in the evening and fall asleep at an appropriate hour at night, increasing the odds of sleeping later in the morning.

Additional Resources
Circadian Sleep Disorders Network
Your Body’s Circadian Rhythm, Explained
Excessive Daytime Sleepiness

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