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InPsych 2014 | Vol 36

Cover feature : Disordered sleep

Shining a light on delayed sleep phase disorder during adolescence

Sleeping like an adolescent? Professor Mary Carskadon (Brown University, USA) – a leader in the field of adolescent sleep research – recently gave a talk in Adelaide titled “Teen sleep: Too little and too late.” This perfectly captures the common issue experienced by so many adolescents across the world. And Australia is no exception. Although Aussie teens do not sleep as little and as late as their peers in Asia and North America, they nevertheless get less sleep on school nights than what they should. Parents and teachers may have observed their sluggish behaviour on school mornings. These teens are frequently called ‘lazy’, ‘difficult’ and even ‘stoned’ by adults. So let’s flip this around so we adults can understand what is going on for them.

Ready to start your day?

Imagine that as of this week you need to get up each morning at 3am. What would you do? It’s likely that you would start with a bit of mathematics. For instance, if you need to get up 3am and you need 8 hours sleep, then counting backwards means you should go to bed at 7pm. So right away you’ve paid more attention to those digital numbers on your clock rather than your own feelings of sleepiness. What are the chances of you falling asleep at 7pm? As you guessed, you lie there awake in the dark, alert like you have not experienced all day, tossing and turning and thinking of those crappy things that happened today, whilst periodically checking the clock as it inches closer to 3am. Then the maths kicks in again. Eventually the alarm shocks you out of your slumber at 3am and you think to yourself “Already?!?” Your body feels the heaviest it has been, you don’t feel stoned but maybe a little drunk, and you have little to no appetite. You have just experienced what a teenager with a condition known as ‘delayed sleep phase disorder’ experiences. The only differences are that they (i) fall asleep somewhere between midnight and 4am, and (ii) have been experiencing this about a thousand-fold longer than you (i.e., approximately five years).

What is delayed sleep phase disorder?

Besides being a very long name that can be condensed to ‘DSPD’, the condition is simply one in which an adolescent’s ‘body clock’ (or less colloquially, their 24-hour circadian rhythm) has been delayed so that it conflicts with day-to-day business. As in the example above, it can be associated with insomnia (i.e., difficulty falling asleep), but recent objective evidence has confirmed that once asleep, these adolescents stay asleep (Saxvig et al., 2013). Yet at the other end of their sleep period is significant daytime sleepiness, as they leave home and attempt to perform at school (if they manage to arrive at school at all). On weekends when morning commitments are removed, the adolescent with DSPD catches up on lost sleep, and will sleep in until late morning, if not early afternoon. But this is temporary relief.

DSPD occurs in young adults but is more common in adolescents. Prevalence estimates in adolescents range from one to 16 per cent. Recent surveys of adolescents show approximately eight per cent fall asleep very late (e.g., after 2am) and wish to wake up very late (Saxvig et al., 2012). A 2013 study in Australia used the full DSPD criteria (American Academy of Sleep Medicine, 2005) and showed less than one per cent of adolescents at high school met diagnostic criteria (Lovato et al., 2013). However, not all adolescents with DSPD attend school (Gradisar et al., 2011), with some turning to home schooling, yet most are at risk of dropping out of school altogether. Therefore, despite these small estimates, the consequence to these affected adolescents is that their pathways to higher education and vocational training begin to slip away week after week that they remain untreated.

DSPD is the most common primary sleep disorder that we see in adolescents at our clinic (and other clinicians in Europe witness the same). Although many psychologists may have adolescents referred to them for other psychological conditions, DSPD may be co-morbid with other disorders. The most common co-morbidities include depression, anxiety and internet gaming disorder.

Although DSPD likely occurred due to multiple rapid changes in the teenagers’ bioregulation of sleep, and they unknowingly went along for the ride, their lives can be reversed by assisting them with some simple changes in their behaviour. And despite the average adolescent with DSPD having experienced the condition for approximately five years (which happens to be coincident with the onset of puberty/high school), his or her sleep pattern can be returned to the norm in a matter of two to three weeks. But first, how do you know if it is DSPD? The diagnosis and treatment is simpler than most psychologists know.

How do I diagnose DSPD?

The International Classification of Sleep Disorders (ICSD) states several aspects of DSPD which can be gleaned by a psychologist in an initial interview. First is determining a delayed sleep pattern. Several questions (and example answers) that can be asked are presented below. The delayed sleep pattern should also be confirmed by the adolescent completing a sleep diary (a free copy of a sleep diary, along with instructions, can be downloaded from www.flinders.edu.au/sabs/psychology/services/casc/home.cfm).

Questions to ask in the initial interview

  • Do you have difficulty falling asleep on school nights? If so, how many of the five nights? Yes, most nights
  • Do you have difficulty getting out of bed on school mornings? Yes
  • What time of the day do you finally feel alert? Recess
  • Is there a time in the afternoon that you feel sleepy or tired? Usually 4pm
  • Do you feel alert after dinner? Yep
  • Do you wake up by yourself (without an alarm or parent) on the weekend? If so, how do you feel when you get up compared to school mornings? On Sunday. Feel heaps better.
  • What problems do you experience due to your current sleep pattern? Usually late for school. Really tired all the time.

Second, the psychologist can query whether the adolescent experiences insomnia when attempting sleep, as well as significant daytime sleepiness (especially in the morning). Third, is to examine sleep on ‘free days’ (i.e., weekends, holidays) – it will probably be late, long and restful sleep. Differential diagnosis is not usually an issue when diagnosing DSPD, as even if co-morbidity exists, the fundamental factor determining when the teenager sleeps is his or her body clock (and the focus of treatment is to shift the body clock earlier). However, investigating other co-morbidities may identify barriers to treatment success (e.g., nightly online gaming, severe depression, etc.). Finally, the impact of the current sleep pattern should be assessed, particularly its effect on school performance and attendance. Once the psychologist is confident the diagnosis of DSPD is correct, it’s time to teach and help them see the light!

I’m a psychologist – not a biology teacher

True, but you need to inform teenagers and their parents about what is happening to them. Why? Because you are likely going to tell them that in order to fall asleep easier at night they need to get light in the morning – and that just doesn’t make sense. Here’s an example to assist, which can be used as part of psychoeducation.

Mike is a 16-year-old boy whose body clock wants him to fall asleep at 4am and wake at noon. Mike’s body clock can be tricked by changing a simple human behaviour – when he opens his eyes. That is, light received by the eyes sends signals to the body clock, which is located in the brain. Light basically resets the body clock – similar to pressing reset on a stopwatch. It says this is when we start the day. Mike’s body clock expects to get light when he would naturally wake up (i.e., noon). But by gradually exposing the eyes to light earlier and earlier each day, it tricks the body clock not only to start the day earlier, but eventually finish the day earlier. Thus, in time, the adolescents will fall asleep earlier. This has been demonstrated with a couple of recent trials in Australia and Europe (Gradisar et al., 2011; Wilhelmsen-Langeland et al., 2014).

Bright light is what is required and this can be sourced from going outside even on cloudy days, for a minimum of 30 minutes of light exposure. If natural bright light is difficult to obtain (e.g., on rainy days), then artificial light can be sourced from various light devices (try Googling ‘bright light therapy’). It is important to be gradually exposed to bright light (whether natural or artificial) to ensure efficacy, and to contrast the bright light exposure with dim light in the evening (e.g., light from a bed lamp or TV, but overhead lights off).

When should adolescents be given bright light?

If we use the example of Mike above, his body clock wants to wake at noon. Mike’s bright light treatment plan is presented below. Bright light is provided 30 minutes earlier each day until Mike’s desired wake-up time. For Mike, he would like to get up at 7:30am to give him time to get ready for school. Bright light (i.e., going outside) is scheduled earlier each day, until eventually Mike wakes at 7:30am. For Mike’s case, this process takes 10 days.

In the end, Mike’s five-year delayed sleep pattern has been reversed in a very short time by changing some simple behaviours, which psychologists are capable of facilitating. Give it a try the next time you suspect an adolescent referred to you has DSPD.

The author can be contacted at michael.gradisar@flinders.edu.au


  • American Academy of Sleep Medicine. (2005). The International Classification of Sleep Disorders: Diagnostic and coding manual, 2nd ed. Worchester, IL: Author.
  • Gradisar, M., Dohnt, H., Gardner, G., Paine, S., Starkey, K., Menne, A., Slater, A., Wright, H., Hudson J.L., Weaver, E., & Trenowden, S. (2011). A randomized controlled trial of cognitive-behavior therapy plus bright light therapy for adolescent Delayed Sleep Phase Disorder. Sleep, 34, 1671-1680.
  • Lovato, N., Gradisar, M., Short, M., Dohnt, H., & Micic, G. (2013). Delayed Sleep Phase Disorder in an Australian school-based sample of adolescents. Journal of Clinical Sleep Medicine, 9, 939-944.
  • Saxvig, I.W., Pallesen, S., Wilhelmsen-Langeland, A., Molde, H., Bjorvatn, B. (2012). Prevalence and correlates of delayed sleep phase in high school students. Sleep Medicine, 13, 193–199.
  • Saxvig, I.W., Wilhelmsen-Langeland, A., Pallesen, S., Vedaa,Ø., Nordhus, I.H., Sørensen, E., Bjorvatn, B. (2013). Objective measures of sleep and dim light melatonin onset in adolescents and young adults with delayed sleep phase disorder compared to healthy controls. Journal of Sleep Research, 22, 365-72.
  • Wilhelmsen-Langeland, A., Saxvig, I.W., Pallesen, S., Nordhus, I.H., Vedaa, Ø., Lundervold, A.J., & Bjorvatn B. (2014). A randomized controlled trial with bright light and melatonin for the treatment of Delayed Sleep Phase Disorder: Effects on subjective and objective sleepiness and cognitive function. Journal of Biological Rhythms, 28, 306-21.

Disclaimer: Published in InPsych on April 2014. The APS aims to ensure that information published in InPsych is current and accurate at the time of publication. Changes after publication may affect the accuracy of this information. Readers are responsible for ascertaining the currency and completeness of information they rely on, which is particularly important for government initiatives, legislation or best-practice principles which are open to amendment. The information provided in InPsych does not replace obtaining appropriate professional and/or legal advice.