Advanced Sleep-Wake Phase Disorder

Have you ever had plans to meet up with friends for an evening concert or movie but just felt too sleepy to be able to go? If so, you have a glimpse into a problem that often confronts people with Advanced Sleep-Wake Phase Disorder (ASWPD).

Most people have encountered a situation in which the need or desire to get to sleep early has come into conflict with planned evening activities. This type of experience is normal when it happens every once in a while, for example after you’ve had poor sleep the night before or an especially exhausting day.

For people with Advanced Sleep-Wake Phase Disorder, though, this is the normal state of affairs. In ASWPD, a person’s sleep schedule is shifted markedly forward, meaning that people with ASWPD go to bed early in the evening and wake up early in the morning. For example, it is common for people with this condition to be extremely sleepy between 6-9 p.m. and to wake up between 2-5 a.m.

If allowed to follow this schedule, people with ASWPD will usually get sufficient sleep and wake up refreshed each morning. But the fact that their sleep cycle is misaligned with that of most of the society and people around them -- including for work, school, and social obligations -- frequently creates problems for both the quantity and quality of sleep that people with ASWPD are able to get.

As a relatively rare condition, it can be difficult at times to find straightforward information about ASWPD. To empower readers with the facts, this guide goes into detail about the definition of Advanced Sleep-Wake Phase Disorder as well as its causes, symptoms, diagnosis, and treatment.

What is Advanced Sleep-Wake Phase Disorder?

Advanced Sleep-Wake Phase Disorder is a specific type of Circadian Rhythm Sleep-Wake Disorder (CRSWD). CRSWD describe conditions in which a person’s normal sleep times do not correspond to the day-night cycle where they live. In ASWPD, times for both going to bed and waking up are significantly earlier than normal.

People who have ASWPD may find it extremely difficult to stay up for very long in the evening and may be extremely sleepy well before a normal adult bedtime. They may start dozing off and feel inclined to turn in for the night as early as 6 p.m.

In the morning, people with ASWPD tend to wake up very early, almost always before 5:30 a.m. and often as early as 2 a.m. When they wake up, they usually are alert, refreshed, or at the least, not able to fall back asleep.

Are There Other Names for Advanced Sleep-Wake Phase Disorder?

Advanced Sleep-Wake Phase Disorder is also sometimes referred to as Advanced Sleep Phase Syndrome (ASPS) or Advanced Sleep Phase Disorder (ASPD). It can be called the “advanced phase type” of Circadian Rhythm Sleep-Wake Disorders.

Because the condition affects the cycle of both being asleep and awake, terminology has moved toward incorporating the phrase “sleep-wake” in describing this and other CRSWD.

Though far from official scientific terminology, people who have an advanced sleep-wake phase may be classified as “early birds” or “larks” because of their ability to be alert and energetic when waking up very early in the morning. The “lion” chronotype can be used to describe people with this sleep pattern as well.

What Are Circadian Rhythm Sleep-Wake Disorders?

Circadian rhythms are processes that follow a cycle of a 24-hour day. When people talk about their daily schedule or internal clock, they are often referring to a circadian rhythm.

Many aspects of the functioning of the human body are controlled by circadian rhythms. These processes are directed by the circadian pacemaker, a part of the brain that operates differently when the eyes are exposed to light.

The most well-known influence of circadian rhythms is on sleep. Every day, the mind and body manage competing drives for wakefulness and sleep. Many factors can influence the strength of these drives, but one of the strongest factors is light. When we are exposed to light, internal processes promote wakefulness, and as light wanes, the sleep drive gains strength. For example, when daylight starts to fade, the body starts to produce melatonin, a natural hormone that enhances relaxation and promotes sleep.

For most people, then, the circadian rhythm of their sleep cycle is closely associated with the day-night schedule where they live. But people who have Circadian Rhythm Sleep-Wake Disorders find that their sleep schedule is not synchronized in this same way. Instead, it may be shifted substantially and in a way that can impact their sleep and their ability to effectively carry out daily activities.

There are multiple types of CRSWD that are classified based on the way a person’s sleep cycle is desynchronized. In ASWPD, the sleep schedule is shifted noticeably ahead of the lightness-darkness cycle.

How Common is Advanced Sleep-Wake Phase Disorder?

Exact numbers for the prevalence of ASWPD are difficult to determine. It is not thought to be common, but surveys and research studies have reported significant variation in their estimates.

For example, a study of around 4,000 adults stated that the prevalence could fall between .25% and 7%. Another study of over 2,000 people who visited a clinic for sleep disorders conservatively estimated that around one in 300 adults -- or about .3% -- have ASWPD.

What Are the Symptoms of Advanced Sleep-Wake Phase Disorder?

The most obvious symptom of ASWPD is the nature of a person’s sleep and wake times as these both occur well before those of most other adults. These times are generally involuntary, meaning that a person feels a nearly irresistible need to sleep at an early hour -- usually between 6-9 p.m. -- and wakes up naturally (without an alarm) between 2-5 a.m.

These early awakenings are often what cause a person to talk with their doctor about sleep problems. With ASWPD, people wake up at this early hour even if they stay up later in the evening. After waking up, they usually cannot go back to sleep when they would like to, a situation called sleep maintenance insomnia.

In many cases, people with ASWPD suffer from sleep deprivation because they are not able to follow their body’s internal clock. For example, if work or social obligations cause a person to stay up until 10 p.m., but they still wake up at 4 a.m., then they are getting only 6 hours of sleep, which is less than the recommended daily amount for adults.

This lack of sleep can have an impact both in the short-term and over time as reduced sleep can accumulate into a “sleep debt.” As a result, people with ASWPD frequently report having excessive daytime sleepiness. Daytime sleepiness can harm productivity and performance at work and can put a person at a higher risk of all types of accidents.

These negative impacts on sleep do not necessarily affect everyone who has an advanced sleep-wake cycle. If a person’s daily obligations and work schedule allow them to go to bed and wake up according to their internal clock, they may find that they have no issues with daytime sleepiness. In some types of work, being an “early bird” may even be seen as beneficial or virtuous.

What Causes Advanced Sleep-Wake Phase Disorder?

The exact causes of Advanced Sleep-Wake Phase Disorder are unknown. It is considered to be a type of intrinsic or endogenous Circadian Rhythm Sleep-Wake Disorder, meaning that it is related predominantly to internal bodily systems of the individual rather than to external causes.

Even though specific causes are undefined, researchers have found that there are some patterns or factors that may make a person more likely to experience ASWPD.

Aging is one factor that commonly influences ASWPD. Many older adults confront serious sleeping problems, and some of those are related to changes in circadian rhythm. As people get older, they tend to get sleepy earlier in the day, reflecting a shift toward a more advanced sleep-wake phase.

ASWPD appears to have a familial component. This means that individuals with ASWPD frequently have at least one relative who has this condition. Familial ASWPD may be caused by mutations to genes that control the internal clock, but no specific genetic explanation has been identified to date.

Though not common, reduced exposure to light or a reduced reaction to light may contribute to an advanced sleep schedule.

What is the Relationship Between Advanced Sleep-Wake Phase Disorder and Depression?

There is still considerable uncertainty about the relationship between ASWPD and depression; however, there are commonalities and potential links between the two conditions.

Sleeping problems are very common among people with depression. These problems can include both sleeping too little (insomnia) and sleeping too much (hypersomnia). Some people with depression experience an advanced sleep phase, in particular with waking up earlier in the morning with limited ability to get back to sleep.

It is unknown if there is a deeper connection between ASWPD and depression. Some research indicates that both circadian rhythms and mood disorders may be affected by similar genes and hormonal patterns.

In addition, while depression can harm sleep, research has shown this to be a bidirectional relationship. Lack of sleep appears to make a person more prone to experiencing depressive episodes and more severe symptoms of depression. In this way, a person with ASWPD who frequently has decreased sleep may be at a higher risk of developing depression.

How is Advanced Sleep-Wake Phase Disorder Diagnosed?

As with most sleep disorders, Advanced Sleep-Wake Phase Disorder must be diagnosed by a medical professional who evaluates whether a person’s situation fits the definition of the disorder that includes particular diagnostic criteria.

To be considered ASWPD, a person must have experienced symptoms for three months or longer. A significant advanced phase shift must be noted, including when a person wants to sleep according to a different schedule. Furthermore, when allowed to sleep according to their internal clock, a person with ASWPD will find that their quality of sleep improves.

Part of the diagnostic process for ASWPD involves reviewing a person’s medical history and symptoms. In addition, a sleep journal or sleep diary is usually kept for one week. Actigraphy, in which movement is tracked, often is used to corroborate data from the sleep journal and arrive at a diagnosis.

Polysomnography, a type of study generally done in a sleep clinic, is not usually necessary to diagnose ASWPD or other circadian rhythm disorders. However, because these conditions can occur alongside other sleep disorders like sleep apnea, polysomnography may be done to rule out those conditions.

Other tests that are not routine but that can be used as part of evaluating a patient with a suspected ASWPD are measuring a person’s core body temperature and their melatonin production. By tracking these measurements, tests can help provide information about a person’s internal clock.

Another component of the diagnostic process is ruling out possible psychiatric causes of the person’s advanced sleep schedule. As discussed previously, depression can cause an advanced sleep-wake cycle, so ruling out depression as an underlying cause is generally part of the overall diagnostic process for ASWPD.

What is the Treatment for Advanced Sleep-Wake Phase Disorder?

Advanced Sleep-Wake Phase Disorder can cause significant issues of sleep deprivation and daytime sleepiness, especially when a person’s family, work, or social obligations keep them up later at night. Treatment for ASWPD typically focuses on trying to adjust a person’s internal clock to be more closely aligned with the day-night cycle.

Unfortunately, there is limited in-depth research about the most effective treatment strategies for ASWPD. The most common treatments include light therapy, chronotherapy, and pharmacotherapy (treatment with medications).

In 2015, the American Association of Sleep Medicine (AASM) published the conclusions of an expert Task Force that focused on developing evidence-based recommendations for the treatment of different CRSWD. For ASWPD, the Task Force found that only light therapy was supported by existing research, and even that has only limited data supporting its efficacy.

The following sections provide more detail about the different types of therapies that may be tried for ASWPD and what research to date has shown about those therapies.

Light Therapy

woman receiving light therapyCircadian rhythms in the body are directly related to light because of the circadian pacemaker in the brain. When exposed to light, the result is to delay the production of melatonin, which is the primary hormone that spurs sleepiness.

Light therapy exposes a person to a strong lamp, and in people with ASWPD, it is administered in the evening in the hours before a person’s normal bedtime. The goal of light therapy is to suppress the person’s sleep drive and melatonin production through the higher dose of light exposure.

Research studies using light therapy in this way have had mixed results: some have shown more benefit than others. Even though light therapy is usually well-tolerated, it requires spending an hour or more in close proximity (within a few feet) of a high-powered lamp, which may be hard for some adults to fit into their daily schedule.

Most people do not experience side effects from light therapy, although in some cases it can cause headaches. It may also pose challenges for people with light sensitivity or people with some psychiatric conditions like bipolar disorder. Anyone considering light therapy should talk with their doctor before initiating this treatment. A doctor may be able to help recommend a specific level of light, duration of exposure, and light therapy lamp.


Chronotherapy is an approach that works to try to shift a person’s sleep and wake times. It is usually done by setting target times and then gradually moving toward those times. This allows a person to slowly get accustomed to a later and later bedtime rather than trying to push it back in one fell swoop.

Evidence for chronotherapy for ASWPD is limited and comes only from case reports of individual patients. No detailed studies have established the efficacy of chronotherapy, and there is no consensus about a method for implementing it as a therapy.


Pharmacotherapy uses medicine to try to address ASWPD and its impact on sleep. There is no strong data from research studies regarding the benefits and risks of pharmacotherapy for ASWPD.

In general, pharmacotherapy for ASWPD involves either melatonin or stimulants.


Melatonin is naturally produced by the body to help us fall asleep and stay asleep. For people with Advanced Sleep-Wake Phase Disorders, melatonin production slows or stops in the wee hours of the night, causing people to involuntarily wake up very early. The lack of melatonin also makes it difficult for people with ASWPD to get back to sleep when this happens.

A way of trying to remedy this is for people with ASWPD to take melatonin supplements immediately upon waking up in the morning with the goal of extending their sleep time and hopefully pushing their internal clock back. Unfortunately, there is no existing data that demonstrates that this is an effective way to treat ASWPD.

Most people are able to take melatonin supplements without any side effects, but some people report gastrointestinal issues. There is some concern that taking melatonin in the morning, especially in larger doses, may end up causing residual sleepiness during the day. To prevent unwanted effects, it is best for any individual to talk with their doctor before beginning to take melatonin supplements.


To try to counteract daytime sleepiness or the sleep drive in the early evening, some people with ASWPD may try using stimulants. These can include things like caffeine or over-the-counter or prescription drugs.

There is no evidence supporting the use of stimulants as a treatment for ASWPD, and they are generally not recommended. Many stimulants can have serious side effects and may be habit-forming. They do not resolve the underlying issues with the internal clock, and as a result, may mask sleep deprivation, leading to greater accumulation of sleep debt.

Because of the potential health risks, patients should never use stimulants without first consulting with their doctor.

Combination Therapy

Light therapy, chronotherapy, and pharmacotherapy may be tried alone or in combination. Unfortunately, there is no sound, established research that can be drawn upon to state that any one method of combination therapy is better or worse than another. Patients are encouraged to collaborate with their health care providers to try to identify the treatment approach that offers them the greatest benefits and fewest downsides.

What Can People With ASWPD Do To Get Better Sleep?

For people with ASWPD, the first and most important step to getting better sleep is to try to find a treatment plan that helps them. Every patient is unique, and what works for one person may be different from what works for someone else.

Beyond pursuing treatments such as those described in the previous section, there are other steps that people with ASWPD can consider to try to improve both the quantity and quality of their sleep.

Address Co-Existing Sleeping Problems

Some people with ASWPD have other sleep disorders as well. For example, someone with ASWPD could also have sleep apnea or Restless Leg Syndrome (RLS). Each of those conditions can cause sleep to be more fragmented and less restful. Obstructive sleep apnea (OSA), in particular, is associated with a range of serious health problems.

When discussing ASWPD with a health professional, patients should be sure to mention any other sleep issues that may be affecting them and to consult with their doctor about therapies that may help. The use of a positive airway pressure device, such as a CPAP or BiPAP machine, for example, can dramatically improve the sleep of people with OSA.

Improve Sleep Hygiene

Sleep hygiene refers to how our environment and habits impact our sleep. Having good sleep hygiene means that our routines and our sleep setting work to our advantage in getting healthy sleep.

Improving sleep hygiene can’t shift a person’s internal clock, but it offers a risk-free way to try to enhance sleep. For example, creating a dark sleeping environment can be useful for people with ASWPD, especially if they are taking morning melatonin supplements because light exposure could counteract the effect of melatonin.

Having a supportive and comfortable mattress along with inviting sheets may also make it easier for patients to get comfortable when trying to shift their sleeping schedule. There are many factors that influence sleep hygiene, and you can find more detailed information in our guide to 15 Tips to Improve Sleep Hygiene.

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