Do you find yourself unable to fall asleep at conventional bedtimes? Do you find your sleep time to be delayed by several hours after midnight? If so, you might be experiencing delayed sleep phase syndrome.
Delayed sleep phase syndrome is a kind of circadian rhythm (a natural internal clock that regulates the sleep-wake cycle in a period of 24 hours) sleep disorder (Nesbitt, 2018). It goes by some other names too, like delayed sleep phase disorder or delayed sleep-wake phase disorder. If someone suffers from DSPS, they are unable to fall asleep at conventional bedtimes; their sleep time is delayed by at least two hours but can also be several hours after midnight. Personal fatigue does not affect falling asleep, as such patients are often tired but still unable to fall asleep immediately. Additionally, another defining quality of DSPS patients is the inability to wake up on time leading to significant interference in work/school life.
Many people suffer from DSPS unknowingly, but adolescents and young adults are the most affected group. Roughly 15 percent (Millman, 2005) of adolescents and adults have DSPS. This condition is different from being a ‘Night Owl’ because Night Owls tend to stay up late of their own accord whilst DSPS patients usually want to go to sleep during the night.
Inability to sleep even when tired: DSPS, a circadian rhythm disorder is most often caused by the inability of the body’s internal clock to reset itself to new sleeping patterns, or not doing it fast enough. In most people, if they go to bed at a different time than they usually do, their circadian rhythm adjusts quickly, and they can fall asleep. But in people who suffer from DSPS, their circadian rhythm is unable to adapt to this new change even if they are tired or suffering from a lack of sleep. Instead, they end up staying awake until their usual bedtime and that’s when their body finally shuts down. As a result, the unchanged circadian rhythm also causes them to wake up at their usual time regardless of the amount of sleep they got the previous night.
Difficulty falling asleep: Patients suffering from DPSD often find it hard to fall asleep at standard bedtime, this is because their internal clock has been delayed, and therefore their brain is signaling them to stay alert instead of falling asleep. Falling asleep usually comes a few hours after midnight between 2 a.m. and 6 a.m. It has been noted that difficulty in falling asleep can be accentuated if the patient tries to stay active and productive during this time.
Difficulty waking up: Of course, this makes sense since falling asleep has been delayed, waking up has to be delayed too. Therefore, getting up at standard times has also been actively defied by the patient’s brain, instead, their internal clock is telling them to keep resting. If left without an alarm, these patients tend to sleep well into midday.
Excessive daytime sleepiness: The previous symptoms are obviously what leads to this one. Daytime drowsiness is basically described as the sleepiness that takes over the patient’s body and mind during the daytime when they are supposed to be active, alert, and awake. Consequently, such a patient may find difficulty in focusing and carrying out normal daytime tasks. Additionally, DSPS is known to completely obstruct the daily routine even if the patient somehow does fall asleep early. This is because even after falling asleep early, they are unable to get a substantial amount of deep sleep. Therefore, this leads to excessive tiredness throughout the day. Often you will find people with DSPS trying to compensate for their haphazard sleep routine by using long daytime naps and excessive bouts of sleep during the weekends when there are no commitments. This is solely justified to ‘make up’ the lost sleep throughout the week. Of course, such a habit can indeed lead to temporary relief, but it is not a solution to the problem.
No other sleep issues: It is often found that patients of DSPS suffer from no other sleep-related illnesses or disorders, for example, sleep apnea. This brings us to our main point- that unless the patient’s schedule doesn’t allow it, they usually get enough quality sleep, just at the wrong time. And as previously established, once DSPS patients have fallen asleep they usually have no trouble staying asleep, the problems only start when it’s time to wake up.
Depression and behavior problems (Sivertsen, 2015): However, there are conditions DSPS patients may develop as a result of their haphazard sleep routine. Most patients tend to suffer from mental illnesses such as depression because of the accumulating stress and fatigue they go through in their daily lives. This stress can be caused by a number of things, poor academic performance, poor work ethic, difficulty focusing, and loss of punctuality, all because of inadequate sleep. It is found, that as a coping mechanism, patients with DSPS often depend on drugs like caffeine, alcohol, or even sedatives to try and bring some peace and order to their lives.
The exact cause of DSPS is still unknown but this disorder does tend to occur in a certain group of individuals more than others. For example, it is common for people to acquire DSPS in their teenage years and carry it on to their adult years, its incidence is the same in both genders. Additionally, people with a strong background in DSPS are also more likely to acquire it which leads us to believe that it has a strong genetic disposition. In fact, research has found 40 percent (Nesbitt, 2018) of people with DSPS have a family history of the disorder. Some environmental causes like lack of sunlight exposure and overexposure to bright lights during the evening are also likely to lead to DSPS.
Furthermore, sudden psychiatric conditions have also been associated with the development of DSPS, these include depression, anxiety, attention deficit hyperactivity disorder, and obsessive-compulsive disorder. A research study has also found that 10 percent (Nesbitt, 2018) of people with chronic insomnia are likely to be affected by DSPS.
DSPS is a disorder that is hard to distinguish from normal disturbances in sleep due to hectic routines, which is why it’s often misdiagnosed. However, if you feel constantly tired, or have a problem waking or falling asleep, you may want to go to a sleep specialist. This usually includes the following:
Providing medical history: This helps your physician narrow down to a few differential diagnoses.
Keep a sleep log: Your physician will ask you to maintain a diary in which you will note down the time you fell asleep and how many hours before that you tried to fall asleep. It may also include the time you got up the following day.
Actigraphy: This exercise requires you to wear a small wrist device that keeps track of your sleep-wake patterns. It is best done when you are on holiday.
Polysomnogram: This is a simple diagnostic test that requires you to spend a night at a hospital in a sleep lab. In a sleep lab, you are observed throughout your sleep by physicians and are often hooked up to an EEG so that your brain waves may be assessed.
Here are some of the diagnostic criteria for DSPS (Sleep 29, 2006):
A delay in the phase of major sleep period in relation to the desired sleep time, for at least three months.
Complaint of inability to fall asleep at a standard time with the inability to wake up at a socially acceptable time.
When not required to maintain a strict schedule, patients show improved sleep quality and duration for their age.
Patients have no difficulty in maintaining sleep once sleep has begun.
Sleep-wake logs for at least two weeks document a consistent pattern of sleep, usually later than 2 am, and lengthy periods of sleep.
The symptoms do not meet the criteria for any other sleep disorder causing the inability to initiate sleep or excessive sleepiness.
Since DSPS is a complex disorder with no known cause, it typically requires more than one method of treatment. However, the goal of treatment remains the same – to normalize the sleep schedule by adjusting the circadian rhythm. Your physician may recommend some of the treatment options listed below:
Advancing your internal clock: This requires patients to go to bed 15 minutes earlier each consecutive night. Additionally, the patient will also wake up earlier each day.
Chronotherapy: This basically means delaying your internal clock. This exercise involves delaying the patient’s bedtime by 1 to 2.5 hours every six days. This is repeated until the patient can follow a normal sleep schedule.
Bright light therapy (Gradisar, 2011): This exercise requires the patient to sit near a light box for 30 minutes right after they wake up. The morning light exposure can help people with DSPS sleep sooner by advancing their internal clock.
Melatonin supplements: Physicians might recommend melatonin supplements. Melatonin is a hormone that controls the sleep-wake cycle. The best amount and timing are different for each person, so it’s important to follow the physician’s exact instructions.
Improving sleep hygiene: Good sleep habits include following a regular sleep schedule and avoiding electronics before bedtime. It may also prove beneficial to avoid the following before going to sleep: caffeine, alcohol, tobacco and vigorous exercise.
Nesbitt, A. D. (2018). Delayed sleep-wake phase disorder. Journal of thoracic disease, 10(Suppl 1), S103.
Millman, R. P., & Working Group on Sleepiness in Adolescents/Young Adults; and AAP Committee on Adolescence. (2005). Excessive sleepiness in adolescents and young adults: causes, consequences, and treatment strategies. Pediatrics, 115(6), 1774-1786.
Sivertsen, B., Harvey, A. G., Pallesen, S., & Hysing, M. (2015). Mental health problems in adolescents with delayed sleep phase: results from a large population‐based study in N Norway. Journal of sleep research, 24(1), 11-18.
Practice parameters for the psychological and behavioral treatment of insomnia: an update. An American Academy of Sleep Medicine report.” Sleep 29, no. 11 (2006): 1415-1419.
Gradisar, M., Dohnt, H., Gardner, G., Paine, S., Starkey, K., Menne, A., … & Trenowden, S. (2011). A randomized controlled trial of cognitive-behavior therapy plus bright light therapy for adolescent delayed sleep phase disorder. Sleep, 34(12), 1671-1680.