What is Delayed Sleep Phase Syndrome?
Delayed sleep phase syndrome (DSPS) is a circadian rhythm sleep disorder and a neurological disorder. It is also known as delayed sleep-wake phase disorder, circadian rhythm sleep disorder- delayed sleep phase type, delayed sleep phase syndrome, delayed sleep phase disorder, delayed sleep phase type or the circadian rhythm sleep-wake disorder-delayed sleep phase type.
People affected with DSPS tend to go to sleep later and wake up later than people not affected with DSPS. People with DSPS usually go to bed from 1 to 4 am and wake up later in the morning around 8 to 11 am. People that are ‘night owls’, people that stay up late normally or people that feel more energy at night have higher rates of getting DSPS.
When people do not have any other sleep problems other than DSPS, they generally sleep well like normal sleepers and it does not bother their sleep quality. If the sleep pattern is not interfering with daily routines and schedules then it may be a normal way of life for them. When the sleep pattern affects daily routines then a diagnosis of delayed sleep phase disorder may be seen. DSPS is seen in about ten percent of all insomnia cases. [1, 2, 4]
The body’s internal clock does not reset or adapt to sleeping patterns in DSPS. Usually when a person goes to bed late their internal clock adjusts itself to allow for more sleep. In DSPS, the body feels tired but maintains its pattern of going to sleep at its usual time and will wake up at its usual time no matter how much quality sleep the person got. These patterns are likely to interfere with people’s daily routines and schedules. This poor pattern of sleeping can lead to long term sleep deprivation. This can negatively impact work, school and family life. Sometimes these individuals are labeled lazy or unmotivated when it is not a choice.
DSPS affects around fifteen percent of adults and teens. Usually DSPS starts in adolescence. DSPS affects both genders equally. There is a genetic link to DSPS. People with a family history are three times more likely to get DSPS than those with no family history.
There are some environmental factors that can contribute to DSPS. Lack of morning sun exposure and bright sun exposure in the evening can affect a person’s circadian rhythm. The exact cause of DSPS is not known. [1, 3]
Signs and Symptoms
- Difficulty falling asleep at the desired time (for at least three months)
- Inability to wake up at the desired time (for at least three months)
- Excessive daytime sleepiness/drowsiness
- Usually no other sleep problems
- Sleeps well through the night with zero to few awakenings in the night
- Some skipped sleep days may occur with a following sleep period lasting up to eighteen hours
- No problems maintaining sleep once sleep has started
- Symptoms do not match criteria for other sleep problems
- Long term health complaints like depression, behavior problems, lowered immune response, anxiety disorders, weight gain, fibromyalgia, diabetes and cancer [2, 3, 4]
People affected with DSPS need to visit a sleep specialist for diagnosis. The sleep specialist will evaluate the sleep patterns, the person’s complaints and history. The sleep specialist will ask for a sleep log of sleep start times and waking times. These patterns can be done via paper or with electronic watches that measure movement. Overnight sleep studies will need to be ordered to rule out all other sleep problems. For research studies, the sleep specialists may conduct melatonin testing and core temperature measuring.
DSPS is an often misdiagnosed problem. People usually try to force a normal sleep pattern on themselves and this can lead to other problems like depression, anxiety, fatigue and fibromyalgia. People sometimes get diagnosed with insomnia when they can’t sleep normally. DSPS is often confused with other psychiatric disorders like schizophrenia and ADHD as well. [2, 3, 4]
- Gradual changes in sleep times
- Bright light therapy in the morning
- Restricting bright light in the evening
- Melatonin medicine in the evening
- Sleep medication
- Phase-delay chronotherapy
- Changing schedules to fit sleep patterns
- Work from home
- Shorter work hours
- Special allowances at school like lighter course work, tests at certain times and taking courses from home
- Good sleep patterns like avoiding caffeine, consistent sleep times, avoiding some stimulant medications, avoiding other stimulants, keeping a cool calm sleep area and avoiding activities before bed [1, 2, 3, 4]
DSPS does not affect a person’s intelligence. Sleepiness can affect the body in different ways like changing a person’s mood, causing concentration problems, memory issues and attention span issues. Adjustments in life at work, home and school can help people that have problems with DSPS. Effective treatment plans can help but always have a risk for relapse. Sometimes people are judged as being lazy or undisciplined as a result of DSPS. This sometimes leads to psychiatric problems. 
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What to read next?
- American Sleep Association, Available from: https://www.sleepassociation.org/patients-general-public/delayed-sleep-phase-syndrome/
- Circadian Sleep Disorders Network, Available from: http://www.circadiansleepdisorders.org/docs/DSPS-QandA.php
- Cleveland Clinic, Available from: http://my.clevelandclinic.org/health/articles/delayed-sleep-phase-syndrome
- Wikipedia, Available from: https://en.wikipedia.org/wiki/Delayed_sleep_phase_disorder
- NYCVA, Available from: http://www.nycva.org/sleep/sleep-center/sleep-important/
- Utah People’s Voice, Available from: http://www.utahpeoplespost.com/2016/01/seniors-poor-sleep-quality-risk-stroke/
- Belmar Health, Available from: http://www.belmarrahealth.com/non-seasonal-major-depressive-disorder-winter-depression-treatable-by-light-therapy/