Delayed Sleep Phase Syndrome

Author: SphynxCat

Many people in the vampire community cite “not being a morning person” as a symptom of real vampirism. This often shares the same signs as Delayed Sleep Phase Syndrome, a circadian rhythm disorder where the person’s normal wake/sleep schedule is shifted 2 or more hours later than what is commonly considered “normal”.

But is it really a vampirism symptom? Well, it’s possible that real vampires are more prone to it than non-vampires, however I doubt it’s specifically a vampire symptom.

Why? Because it is VERY easy for it to be a self-fulfilling prophecy more so than anything else – the sleep schedule of many mundanes often become permanently “shifted” by voluntarily staying up late (college kids and overnight “cramming” study sessions before exams is one good example) or working late shifts, especially for long periods of time. Fortunately, the world in general is increasingly moving towards the concept of the 24-hour workplace, so someone with Delayed Sleep Phase Syndrome – DSPS – has a wider choice of jobs now than, say, 20 or 30 years ago.

This article will explain more about DSPS and it’s effects on people.


Delayed Sleep Phase Syndrome (DSPS), or just Delayed Sleep Phase (DSP) is a circadian rhythm (internal clock) disorder. People with DSPS have a sleep pattern that is delayed by two or more hours from what’s considered “normal,” leading to delayed bedtimes and wake times. DSPS is more common in teenagers than in the adult population – some people “grow out of it”, but for others it stays for the rest of their lives.

It needs to be stressed that when people with DSPS are allowed to follow their body’s natural schedules (and don’t have any other concurrent issues affecting their sleep), they WILL get sufficient sleep and WON’T have any problems staying awake during their normal waking times. For example, working 2nd shift – evenings – will be much less of a problem for someone with DSPS than for someone with a more conventional sleep schedule. If the sleep schedule is shifted far enough, even 3rd shift – overnights – becomes easier to work.

However, because these schedules often don’t match school or (most) work schedules, quite often a person with DSPS will NOT get sufficient sleep when trying to maintain a more conventional schedule, which will result in excessive fatigue, daytime sleepiness, and related problems and potential health risks. (Sleeping at the wheel is one of the more common causes of traffic accidents, for example, and is always a risk when you haven’t had enough sleep.) In such situations, this condition then becomes more of a “disorder” than just normal habits.

To put it more simply, DSPS is only an issue if it’s impacting daily life. If you can adjust your daily schedule to work with it, then you’re usually ok.

According to the – USA – Americans with Disabilities Act of 1990, “disability” is defined as a “physical or mental impairment that substantially limits one or more major life activities”. “Sleeping” is defined as a “major life activity” in § 12102(2)(a) of the statute.


The ICSD (“International Classification of Sleep Disorders”) diagnostic criteria for DSPS (as per internal page 132 of the 2001 edition linked below) are as follows:

A. The patient has a complaint of an inability to fall asleep at the desired clock time, an inability to awaken spontaneously at the desired time of awakening, or excessive sleepiness.

B. There is a phase [time] delay of the major sleep episode in relation to the desired time for sleep.

C. The symptoms are present for at least 1 month.

D. When not required to maintain a strict schedule (e.g., vacation time), patients will exhibit all of the following:
D-1. Have a habitual sleep period that is sound and of normal quality and duration
D-2. Awaken spontaneously
D-3. Maintain stable entrainment [sticking to] to a 24-hour sleep-wake pattern at a delayed phase [time]

E. Sleep-wake logs that are maintained daily for a period of at least two weeks must demonstrate evidence of a delay in the timing of the habitual sleep period.

F. One of the following laboratory methods must demonstrate a delay in the timing of the habitual sleep period:
F-1. Twenty-four-hour polysomnographic monitoring (or by means of two consecutive nights of polysomnography and an intervening multiple sleep latency test)
F-2. Continuous temperature monitoring showing that the time of the absolute temperature nadir is delayed into the second half of the habitual (delayed) sleep episode

G. The symptoms do not meet the criteria for any other sleep disorder causing inability to initiate sleep or excessive sleepiness.

Minimal Criteria: A plus B plus C plus D plus E.

The severity is graded on how long the patient is awake past the the desired sleep time, IF the desired sleep time is at what is considered to be more normal for the average day shift person. The later at night/earlier in the morning (depending on your point of view) the patient’s body forces sleep, the more severe it is graded – the most severe cases are considered to be 4 or more hours later than what is considered normal for day shift.


Generally the patient will be first advised to maintain a log of their wake/sleep times. This will be the fastest way to see whether you’re getting a full sleep cycle’s worth of sleep at any time, or if you’re always short on sleep despite your best efforts. This is the first step in differentiating DSPS from other sleep issues such as sleep apnea, medication-caused sleep issues, pain, anxiety issues and so on. Track waking and sleeping times, the lighting conditions at sleeptime and wake time, the ambient lighting of the room, color of the lighting, food/drink every day, pain levels (if applicable) and anything else you can think of.

The doctor or other medical professional will ask about your medical history (to determine whether there are any other factors involved), ask about your levels of tiredness and it’s effects on your daily life, and talk with you to determine whether you are more of an evening person or a morning person.

If another sleep disorder is suspected, a sleep study may be recommended to monitor things like brain activity and body temperature fluctuations.


If the patient desires – or feels they need – treatment to adjust their sleep schedule, treatment may consist of one or more of the following:

Bright Light Therapy
This works by increasing the amount of natural sun exposure – or it’s equivalent – in the morning and avoiding it late in the day. Specially designed “daylight bulbs” may be more useful to some if sun exposure isn’t practical. These daylight bulbs can be acquired in various forms, such as a light box, a desk lamp, and even a visor that you wear.

This involves making the patient’s bedtime earlier by 2-3 hours per day until the desired bedtime is reached. Once the desired time is reached, then the schedule should be rigorously maintained.

Improving sleep hygiene
Various sleep hygiene improvements will be suggested such as maintaining a regular sleep schedule – even on weekends, limiting activities for a few hours before bed that would keep the patient awake, making the sleep environment more comfortable, and avoiding caffeine and other chemical stimulants before bedtime.
(You can see some additional tips in my Insomnia article.)

Melatonin supplements
Because melatonin plays a role in signaling the body to sleep, taking the supplement in the afternoon or early evening helps some patients with DSP.


If the patient is able to rearrange their work/life schedule around their DSPS sleep schedule, THERE IS NO PROBLEM.

This is an important thing to understand, because many doctors still believe that the only “good” sleep schedule is one that’s on day shift – and not everyone is wired that way!

There are plenty of professions today where workers are required around the clock, so these days there are a wider variety of employment options for someone with DSPS.

~SphynxCatVP, August 2010

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