Key Takeaways
  • Advanced sleep phase disorder is characterized by early evening sleepiness and early morning waking.
  • An earlier sleep-wake cycle can interfere with daily life and potentially cause sleep deprivation and early morning insomnia.
  • ASPD may be treated with bright light therapy and behavioral changes.

Many people identify as early birds, naturally waking up and feeling more productive in the morning. However, some people wake up so early in the morning and fall asleep so early at night that it significantly disrupts their sleep-wake cycle. When a person is unable to adjust their early bird sleep schedule, it may be a sign of advanced sleep phase disorder (ASPD).

What Is Advanced Sleep Phase Disorder?

Advanced sleep phase disorder (ASPD) describes a condition where a person has a sleep schedule that consistently runs earlier than desired . For example, a person with ASPD may fall asleep between 6 p.m. and 9 p.m. and wake up between 2 a.m. and 5 a.m. A person with ASPD may still be able to get enough sleep overall, but their sleep schedule is shifted earlier than the average person.

ASPD is a type of circadian rhythm sleep-wake disorder, a category of sleep disorders that also includes jet lag, delayed sleep phase disorder, and non-24 hour sleep wake disorder. These disorders affect people whose circadian rhythms are irregular or run at times that are out of sync with their environment or social expectations.

The circadian rhythm is an internal biological clock that regulates sleep-wake cycles, as well as the release of hormones related to sleep, appetite, and core body temperature. The circadian rhythm of a person with ASPD operates on an earlier schedule, so melatonin, the sleep hormone, is released earlier.  This means someone with advanced sleep phase disorder is likely to get sleepy earlier .

Advanced vs. Delayed Sleep Phase Disorder

Advanced sleep phase disorder (ASPD) and delayed sleep phase disorder (DSPD) are both circadian rhythm sleep-wake disorders, but the symptoms are on opposite sides of the spectrum. While a person with ASPD has an internal body clock that runs earlier, a person with DSPD has a circadian rhythm that runs later. A person with ASPD may struggle to stay awake in the evening, while a person with DSPD can stay up late but has difficulty feeling alert in the morning.

ASPD and DSPD are also different in terms of who is likely to be affected by them. Older people are more likely to have ASPD, while younger people are more likely to have DSPD. ASPD is also less common than DSPD, but that could be because it is underdiagnosed, given that an earlier schedule generally works better with societal expectations.

People with either disorder can face challenges because their sleep schedule is out of sync with others’, which can cause problems at work, at school, and in social situations.

Symptoms of ASPD

A person with advanced sleep phase disorder may show symptoms such as:

  • Falling asleep during the late afternoon or early evening
  • Waking up very early in the morning and being unable to fall back asleep
  • Falling asleep and waking up earlier than they would prefer

If a person with ASPD is allowed to sleep according to their natural schedule, their sleep quality often improves, and they are able to get enough sleep.

Effects of ASPD

Advanced sleep phase disorder can be challenging to live with. It can affect many aspects of a person’s life beyond when they go to bed and when they wake up.

Sleepiness During Evening Events

People with ASPD may have difficulty staying awake when attending social activities that are scheduled during the late afternoon or evening. They may fall asleep during a nighttime social or family event, which can damage their social relationships.

Chronic Sleep Deprivation

People with ASPD may feel obligated to attend social events or engage in other activities that keep them up past their natural bedtime. Even if they manage to push their bedtime later, they may still wake up very early in the morning, causing them to miss out on sleep. Over time, this can lead to sleep deprivation, which includes symptoms like sleepiness, lack of focus or concentration, or slower reaction times during the day.

Emotional Distress

People with advanced sleep phase disorder may have trouble staying awake during work, social, or family events that take place at night, which can cause distress or strain their relationships. Since they also have trouble getting back to sleep after waking up early in the morning, they may worry they have insomnia or depression. However, while people with depression may wake earlier, they typically do not feel the sleepiness people with ASPD experience in the evening.

Misuse of Stimulants, Alcohol, or Drugs

To help themselves stay awake, people with advanced sleep phase disorder may use caffeine or other stimulants in the afternoon or early evening. In the morning, they may use alcohol, sedatives, or sleeping pills to help them sleep in. However, using these substances will only further disrupt their sleep, leading to increased sleep deprivation and other adverse side effects.

Causes of ASPD

Several factors may contribute to advanced sleep phase disorder, including:

  • A family history of ASPD
  • Older age
  • Autism spectrum disorder
  • Too much exposure to morning light
  • Environmental factors, such as work schedules

Diagnosing ASPD

When diagnosing advanced sleep phase disorder, it is important to discuss specific symptoms and rule out any other potential causes. This is because the symptoms of ASPD could also be caused by a physical or mental health condition, or another sleep disorder. Medication side effects or substance abuse can also present with similar symptoms.

Tracking sleep quality and duration with a sleep diary can help rule out other conditions. An actigraph, which is worn on the wrist like a smartwatch or fitness tracker, can provide additional important insights. This device records sleep activity and provides data that can be used with the sleep diary to diagnose ASPD.

In rare cases, a doctor may recommend a polysomnogram, a sleep study that is performed overnight in a lab. During a polysomnogram, the patient’s brain waves, heartbeat, breathing rate, body movements, and oxygen levels are monitored while they sleep . Polysomnograms can be helpful for ruling out other sleep disorders that may cause symptoms similar to ASPD, like obstructive sleep apnea.

Treatments for ASPD

Some people may make small adjustments to their lives in order to accommodate ASPD. For example, they may arrange their daily routine to work around their preferred sleep schedule. They may choose to treat their symptoms with a mix of lifestyle changes, bright light therapy, improved sleep hygiene, and melatonin.

Bright Light Therapy

Bright light therapy is used to treat a number of circadian rhythm sleep-wake disorders, including ASPD. At specific times of day, people sit in front of a specialized light device with a brightness designed to mimic the power of the sun with a brightness around 2,000 to 2,500 lux. To help reset their circadian rhythm, people with ASPD may use the device in the evening between 7 p.m. to 9 p.m.

Bright light therapy has shown to be effective in pushing bedtime later for people with ASPD. Additionally, doctors may recommend keeping the lights low or wearing light-preventing goggles in the morning as too much morning light can reinforce an earlier sleep schedule.

Lifestyle Changes

Following good sleep hygiene, like keeping a regular sleep schedule, can help improve sleep quality. Doctors may also recommend avoiding caffeine, stimulants, alcohol, or other drugs. These substances disrupt sleep and can worsen symptoms of sleep deprivation or sleepiness.

Follow a Regular Sleep Schedule

Healthy circadian rhythms are reinforced by consistent schedules, including exposure to light and darkness at regular times. For more energy and better sleep, try to follow the same sleep schedule every day, including weekends.

Avoid Caffeine, Alcohol, and Other Substances

Some people with ASPD may use caffeine, alcohol, or other drugs to boost their alertness in the late afternoon or to help them sleep in. However, these substances only further disrupt sleep.


Depending on the symptoms, doctors may recommend people with ASPD take melatonin to help regulate their sleep-wake cycles. However, there is not yet sufficient evidence that melatonin works as a treatment for ASPD.

When to Talk to a Doctor

It is not always possible for people to adjust their work or social schedules to their early sleep schedule. For those whose natural sleep-wake schedule is interfering with their quality of life, a doctor may be able to help clarify symptoms and provide treatment recommendations.

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6 Sources

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