Advanced Sleep Phase Disorder
A circadian rhythm disorder where the sleep-wake cycle is advanced by several hours, causing early evening sleepiness and very early morning awakening.
What is Advanced Sleep Phase Disorder?
Advanced Sleep Phase Disorder (ASPD) is a circadian rhythm sleep disorder in which a person's internal clock is set significantly earlier than desired or socially practical. Individuals with ASPD feel compelled to sleep in the early evening (6-9 PM) and wake very early in the morning (2-5 AM). While their sleep is normal in quality and duration, the timing conflicts with work, social activities, and family life. ASPD is the opposite of delayed sleep phase disorder and is more common in older adults.
Prevalence
ASPD is relatively rare, affecting approximately 1% of middle-aged adults. It is more common with advancing age, as circadian timing tends to shift earlier with aging. The disorder can run in families, with some cases linked to specific genetic mutations. Unlike the natural tendency toward 'morning type' that develops with aging, ASPD involves pathologically early sleep timing that causes significant impairment.
Causes
ASPD results from an abnormally short intrinsic circadian period (internal day shorter than 24 hours), genetic mutations in clock genes (particularly PER2 and CRY2), and altered sensitivity to light timing cues. A familial form (FASPS - Familial Advanced Sleep Phase Syndrome) has been identified with autosomal dominant inheritance. Age-related changes in circadian timing may also contribute, as older adults naturally tend toward earlier schedules.
Symptoms
Early evening sleepiness
Overwhelming sleepiness in the early evening (6-8 PM), making it difficult to stay awake for evening activities, social events, or family time.
Early morning awakening
Waking very early (2-5 AM) and being unable to return to sleep, despite desiring more sleep.
Normal sleep when following natural schedule
If allowed to sleep from early evening to early morning, sleep quality and duration are normal.
Difficulty with evening social activities
Missing evening social events, dinner parties, and family activities due to irresistible sleepiness.
Early morning loneliness
Waking hours before others in the household, potentially leading to isolation during early morning hours.
Sleep deprivation if fighting the schedule
Forcing oneself to stay up late leads to sleep deprivation since early awakening persists regardless.
Diagnosis
Self-Assessment Questions
If you answer yes to any of these questions, consider consulting a sleep specialist:
- 1Do you feel very sleepy in the early evening and struggle to stay awake past 8 PM?
- 2Do you wake up very early (before 5 AM) and find it impossible to go back to sleep?
- 3Has this pattern persisted for months or years?
- 4Is your sleep normal and refreshing when you follow your natural early schedule?
- 5Does this pattern cause problems with evening work, social life, or family time?
- 6Do you have family members with similar extremely early sleep patterns?
Diagnosis involves documenting persistently early sleep and wake times through sleep diaries and actigraphy, confirming normal sleep when following the advanced schedule, and ruling out other causes of early awakening such as depression.
Sleep Diary
A 2+ week log showing consistent early evening sleep onset (typically before 8-9 PM) and early morning awakening (before 5 AM).
Actigraphy
Wrist-worn monitoring for 1-2 weeks objectively confirms early and stable sleep-wake timing.
DLMO (Dim Light Melatonin Onset)
When available, confirms abnormally early timing of melatonin secretion, consistent with the advanced circadian phase.
Polysomnography
Not typically needed unless there's concern for sleep apnea or other disorders. Would show early sleep onset and normal sleep architecture.
Depression Screening
Depression can cause early morning awakening and should be ruled out, though it typically differs from ASPD in presentation.
Treatment
Treatment aims to delay (shift later) the circadian clock using evening light therapy, avoiding morning light, and sometimes low-dose melatonin in the morning. Maintaining the shift requires ongoing intervention.
Evening Bright Light Therapy
Exposure to bright light (2,500-10,000 lux) in the evening, typically 2-3 hours before the undesired early sleep time, helps delay the circadian clock.
Morning Light Avoidance
Avoiding bright light in the early morning (using dark glasses or staying indoors) prevents further circadian advance.
Morning Melatonin
Low-dose melatonin taken in the morning (upon awakening) may help delay the clock, though this use is less well-studied than evening melatonin for DSPD.
Gradual Schedule Delay
Slowly pushing bedtime later by 15-30 minutes while using evening light and morning light avoidance.
Lifestyle Accommodation
When treatment is insufficient, adjusting work and social schedules to accommodate early timing may be the most practical approach.
Lifestyle Adjustments
- •Use bright light (light box or outdoor light) in the late afternoon/early evening
- •Wear dark sunglasses or blue-light blocking glasses in the early morning
- •Stay active in the evening with stimulating activities to resist sleepiness
- •Maintain a consistent schedule even on weekends
- •Exercise in the late afternoon or early evening
- •Avoid morning bright light exposure when possible
- •Consider scheduling important social activities earlier in the evening
- •Communicate with family and friends about your sleep needs
Find a Specialist
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