By Brandon Peters, MD
Night owls rule the evening roost. What explains the natural desire to stay up late and sleep in, especially in teenagers? With this overview, discover the causes, symptoms, diagnostic testing, and treatments of delayed sleep phase syndrome. Consider the consequences, including insomnia and sleep deprivation, and what can be done to keep the condition in check.
What Is a Night Owl?
First, how is a night owl defined? Anyone who stays up later than most may be viewed as a potential suspect. However, those with delayed sleep phase syndrome may be birds of a different feather.
If the natural tendency to fall asleep is delayed by at least several hours compared to the average person, with a sleep onset closer to 1 to 3 a.m., this fits the bill. In some cases, the delay may be even more extreme, with a night owl going to sleep closer to sunrise.
The desire to wake up is similarly delayed by at least several hours. Someone who is characterized as a night owl may not desire to wake until 10 a.m. or later. With a sleep onset closer to sunrise, the affected person may not desire to wake until into the early afternoon.
How Common Is Delayed Sleep Phase Syndrome?
It is estimated that 10 percent of the population could be characterized as night owls with delayed sleep phase syndrome. It may be more common among teenagers, who are susceptible to a slight delay in their sleep timing, but it can persist throughout life. There are many retired people who experience the condition once the alarm clock is silenced!
What Causes a Delayed Sleep Phase?
There seems to be a genetic predisposition towards developing delayed sleep phase syndrome. Some of this science is understood. For example, a mutation in the CRY1 gene alters the human circadian clock, delaying sleep by 2 to 2 1/2 hours compared to non-carriers. There will likely be more genes identified that have a role.
Approximately 40 percent of people with delayed sleep phase syndrome report a family history of the condition.
Beyond genetic programming, there are environmental factors that may unmask the condition. Most importantly, light has powerful effects on the timing of the circadian system. It may provoke the delay in sleep timing, and may also be used to correct the condition.
Understanding the Circadian System and Sleep
Sleep is dependent on two processes: sleep drive and the circadian alerting system. If isolated in a constant environment, like a cave, the genetically determined circadian timing will become evident. It is controlled by the suprachiasmatic nucleus, a region of cells in the hypothalamus of the brain, and highly influenced by light exposure. Every cell, and organ, in the body follows a circadian pattern.
For most people, this internal clock is programmed to run a little long, perhaps resetting every 24 1/2 hours. In the cave, without exposure to light variance, an isolated person would naturally fall asleep and wake 30 minutes later, shifting later each and every day. In a week, the timing of sleep would move 3 1/2 hours. In a month, it would shift 14 hours, so that the person would want to sleep during the natural day and be awake in the natural night. This natural drift in the circadian timing is reset with morning sunlight.
Exposure to natural light in the early morning hours is a signal to the brain for wakefulness. It makes it easier to wake. It also slightly shifts the timing of sleep earlier, making it easier to fall asleep. This helps to align the desire for sleep to the natural period of darkness overnight. Without it, significant problems can develop with sleep and health.
What Are the Symptoms of Delayed Sleep Phase Syndrome?
People with delayed sleep phase syndrome will generally experience two symptoms: insomnia and sleepiness. Why would these seemingly contradictory symptoms occur in the same person? Again, it comes back to a question of when—it comes back to timing.
Insomnia
Most night owls will experience significant insomnia if they attempt to go to bed earlier than their natural desire for sleep onset. Crawling into bed at 10 p.m. may result in hours of lying awake, tossing and turning. This can provoke anxiety, frustration, and anger—feelings that make the insomnia worse. When left to stay up late on weekends or during vacation breaks, it suddenly becomes much easier to fall asleep.
Morning sleepiness
In the early morning hours, it can be difficult to wake a night owl. It’s like trying to wake the dead. Teenagers have to be dragged out of bed, splashed with water, or roused with threats from despondent parents. This morning sleepiness can be profound. Depending on the hour, it is akin to waking someone with normal sleep timing in the middle of the night. It is extremely difficult to wake and function. By midday, however, the sleepiness abates. When the late evening rolls around, the night owl feels very awake, repeating the cycle again.
Social Pressure Leads to Sleep Deprivation
Unfortunately, night owls are not typically allowed to sleep and wake when their bodies tell them to. If they could always go to bed at 2 a.m. and wake at 10 a.m., there would be no sleep problem. They would fall asleep easily, without insomnia, and wake easily without conflict. Unfortunately, pressure from the rest of society—parents, spouses, bosses, school systems—may be quite disruptive. Without accommodation, chronic tardiness and absenteeism can lead to educational and professional dysfunction.
If someone does not naturally fall asleep until 2 a.m., but has to wake at 6 a.m. to be to work on time, sleep deprivation inevitably results. Unfortunately, 4 hours of sleep is not enough to meet even basic sleep needs. This can have profound effects on health and well-being. Consider some of the symptoms associated with sleep deprivation:
Sleepiness
Fatigue
Difficulty concentrating
Memory problems
Mood changes (depression, anxiety, or irritability)
Errors or accidents
Physical pain
Hallucinations
Paranoia
There is some evidence this can be fatal. This is likely due to the chronic effects of sleep deprivation. One study suggests that people with delayed sleep phase syndrome have a 10 percent higher risk of dying compared to controls.
How Is Delayed Sleep Phase Diagnosed?
With proper education, it becomes fairly easy to recognize night owls who are likely experiencing delayed sleep phase syndrome. It may be a lifelong affliction, starting in adolescence and persisting for decades. How can it be diagnosed?
Fortunately, testing is not required to reach a diagnosis. A careful history by a board-certified sleep physician can typically identify the condition. In some cases, sleep logs kept over weeks may aid the recognition. Rarely is testing with actigraphy needed.
In research settings, the measurement of melatonin levels can help to identify the circadian timing. In particular, the dim light melatonin onset (DLMO) measured via blood or saliva can establish the pattern. Unfortunately, the repeated sampling requires a carefully controlled laboratory environment. This is virtually never done in a clinical practice. More recently, a blood test called TimeSignature has been developed, but it is not widely available.
Treatments of Delayed Sleep Phase Syndrome: Light, Melatonin, and More
If a condition is genetically determined, and potentially lifelong, it may seem like a life sentence. Fortunately, for delayed sleep phase syndrome, this is not the case! There are some effective ways to keep the timing of sleep in a normal phase. It may require a little extra effort, but consider these potential helpful interventions:
Sleep schedule consistency
There is good evidence that night owls can maintain a socially acceptable sleep timing. This requires consistency, especially in regard to the wake time. Get up at the same time every day, including weekends. Do not sleep in. Go to bed feeling sleepy, even if this initially requires a delay in the preferred bedtime. This will make it easier to fall asleep faster, relieve pressure to sleep, and reinforce the sleep quality.
Morning sunlight
It is especially important to reset the timing of sleep with morning sunlight. This is most effective immediately upon awakening. Try to go outside for 15 to 30 minutes upon awakening. Wake with an alarm, throw on clothes, and immediately get outside. Take a walk. Read the newspaper in the garden. Check social media while facing the sunrise. Light should hit the eyes, but don’t stare directly into the sun. Even a cloudy or rainy day, try to stick to the routine. In winter months, a light box may be necessary for phototherapy. The effects may take up to 1 month to become evident.
Avoid light at night
Artificial screen light should be minimized at night, especially in the hours preceding bedtime. It may shift the timing of sleep to occur later, causing insomnia and morning sleepiness. Devices may be switched to night mode, cutting out the blue light that can shift sleep timing. Blue blocker sunglasses (with an amber tint) or screen covers may be employed. Best yet, simply shut down the electronics in the 2 hours before bedtime. The buffer zone before the goal bedtime should be spent relaxing.
Melatonin
Melatonin is a hormone produced overnight by the pineal gland in the brain. It can be an external signal to the circadian system, most effective among the blind. If taken up to 6 hours before the desired bedtime, it may help night owls to fall asleep earlier. The effects may be somewhat weak, and certainly overpowered by the effects of light.
Cognitive behavioral therapy for insomnia (CBTI)
This effective treatment helps to improve the patterns of sleep and one’s relationship to it. Sleep consolidation, stimulus control, mindfulness, and relaxation techniques may be integrated into a program. It may be guided with help from a psychologist, class, online course, or book.\
Chronotherapy
Rarely, it may be necessary to adjust the timing of sleep incrementally in a structured environment. It is difficult to carry out at home and may require hospitalization. Over successive days, the sleep period may be delayed by 1 to 2 hours until the desired timing of sleep is achieved. Poorly timed light may complicate the efforts, and strict adherence to the final schedule must be observed.
Prescription medications
Sleeping pills and stimulant medication to enhance alertness have a limited role in this condition. Generally, they will be weakly effective. As a result, they may be overused and even abused. The risk of overdose in night owls, especially when these medications are used in combination with alcohol, is high. Instead of masking symptoms with a drug, the underlying timing of the circadian rhythm should be corrected.
Social awareness
Education may help parents to appreciate what their teenager is experiencing, to know that it is not laziness or defiance. High schools should continue to accommodate this natural timing among their students by shifting the school day. Later school start times enhance academic performance, reduce tardiness and truancy, and even diminish car accidents among teens.
Conclusion
Sleep deprivation can have serious impacts on health and well-being. If you are struggling with delayed sleep phase syndrome, consider seeking the guidance of a board-certified sleep physician. Start with some simple advice: Go to bed feeling sleepy (even if later), keep a consistent wake time, and get sunlight upon awakening. If more help is needed, seek it out.