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Delayed Sleep Phase Syndrome (DSPS)

  • DSPS is a circadian rhythm disorder, a problem with the timing of the sleep phase within the 24 hour day
  • People with DSPS find it very difficult to get to sleep until the early hours of the morning, and if able to, will sleep in until at least late morning
  • Work, school, and social demands often mean that the amount of sleep is not sufficient

Overview of Delayed Sleep Phase Syndrome

Delayed sleep phase syndrome affects fewer than 1 in 500 adults, but is much more common in adolescents, affecting at least 7%. Many more adolescents, especially males, experience mild delayed sleep and is accepted as a common part of puberty.

If it wasn't for work, school, family, or social expectations, the DSPS sufferer would get plenty of good quality sleep. There is nothing wrong with the quality of their sleep when allowed to sleep on a schedule of their choosing. Unfortunately, few people have this privilege, meaning that they only get 5 or so hours of sleep. Some will try to get to sleep at a 'normal' time but because the circadian rhythm is offset, they find it very difficult, if not impossible to get to sleep earlier – they are not flexible sleepers. This leads to complaints of insomnia – in fact about 10% of people who go to their doctor complaining of not being able to get sleep are there because they have DSPS.

Symptoms of Delayed Sleep Phase Syndrome

DSPS can be classified as being mild, moderate, or severe – mild DSPS may only be a shifting of preferred bedtime by two hours compared to the normal. These people are often described as night owls, and can get by usually  with the lower amounts of sleep they typically would get. In fact, at weekends, while at college, or in a flexible work environment, it may be possible for the DSPS to get all the sleep he or she requires. Moderate and severe DSPS represent a shift of 3 and 4 hours respectively – these shifts are more difficult to cope with, leading to lower sleep amounts, tiredness, and more napping to compensate.

Causes of Delayed Sleep Phase Syndrome

Just like advanced sleep phase syndrome, people with DSPS have an abnormal response to how light resets their clock. Light in the evening may help keep them awake. Research shows that DSPS may be linked to a particular gene – it is common for DSPS to be passed down generations.

Other causes can include damage to the area in the brain that controls the circadian rhythm. This damage could be due to trauma or cancer.

Treatment for Delayed Sleep Phase Syndrome

Treatment for DSPS lies in correctly diagnosing the problem – people who try to get to sleep at a 'normal' time will lie awake for hours and a doctor may conclude that the person has insomnia. However a typical insomniac won't be able to stay asleep in the morning and the treatment is different. It is therefore important that your doctor asks you the right questions if you believe you have DSPS.

Treatment involves retraining the biological clock using light therapy, behavior modification, and medication. A commonly used medication is melatonin – a natural hormone found in most humans and some plants that helps regulate the biological clock. Light therapy involves decreasing the amount of light in the evening, and increasing it at the appropriate time in the morning. Some people with DSPS, either naturally or after a correct diagnosis, make adjustments to their lifestyle that help negate the problems their sleeping habits cause – for example, switching to an evening or night shift.

If you believe you have symptoms that match those above, talk to your doctor or sleep specialist.