Circadian Health Glossary
Non-24-Hour Sleep-Wake Disorder (Non-24)
Non-24-Hour Sleep-Wake Disorder (Non-24) is a circadian rhythm disorder in which an individual’s internal body clock does not align with the 24-hour day. This results in a sleep-wake cycle that gradually shifts later each day, often disrupting daily functioning and social schedules.
Who Is Affected by Non-24?
- Most commonly occurs in blind individuals who lack light perception, as they cannot use natural light to synchronize their circadian rhythms.
- Rarely, it can also affect sighted individuals due to underlyingcircadian rhythmdysfunction.
Symptoms of Non-24
- Difficulty falling asleep and waking at conventional times.
- Periods ofinsomniaalternating with excessive sleepiness.
- A constantly shiftingsleepschedule that becomes increasingly misaligned with daily life.
How Is Non-24 Treated?
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Light Therapy: For sighted individuals, controlled light exposure can help reset the circadian clock.
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Melatonin or Tasimelteon: Medications that mimic the natural signals regulating circadian rhythms may help align sleep patterns.
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Behavioral Strategies: Consistent routines and structured environments may assist in managing symptoms.
Non-24 disrupts normal life patterns, but with proper management, individuals can improve sleep and quality of life.