What is delayed sleep-wake phase disorder?
Does your child stay up very late and have great difficulty waking up for school in the morning? Does he or she seem tired during school hours, but then can't fall asleep until well after midnight? On school vacations, does your child naturally go to bed at 2 or 3 a.m. and sleep until after noon, waking up feeling refreshed?
It might be that your child is suffering from delayed sleep-wake phase disorder (DSWPD), a circadian rhythm disorder that occurs when a child's natural sleep and wake schedule is shifted later, by at least several hours, and thus conflicts with daily obligations such as school attendance.
Children with DSWPD typically cannot fall asleep at the appropriate or desired time of night, but are able to fall asleep readily around midnight or later. The natural morning wake time is similarly delayed, often making it extremely difficult to become alert before the late morning or early afternoon. The times of day when children “feel their best” are also shifted later, so that they may feel most alert and functional in the mid-afternoon or late at night. When allowed to sleep on their preferred later schedule, most children with DSWPD feel rested and can function well. However, when their natural schedule conflicts with normal school, work or lifestyle demands, delayed sleep-wake phase disorder can impair a child’s functioning during the day. Untreated, DSWPD can lead to social impairment, academic and behavioral problems, and depression.
This disorder is most common in adolescents and young adults. Between 7 and 16 percent of adolescents exhibit symptoms of delayed sleep-wake phase disorder.
Care for delayed sleep-wake phase disorder
Specialists at Boston Children's Hospital's Sleep Center are experienced in treating children who have DSWPD, so your whole family can get a good night's sleep.
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- Call us at 781-216-2570
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Delayed Sleep-Wake Phase Disorder | Symptoms & Causes
What are the symptoms of delayed sleep-wake phase disorder?
If your child or adolescent is suffering from DSWPD, he or she might experience:
- A persistently later than desired "sleep onset," or the time that the body falls asleep easily for the night, often after midnight. He or she will have a natural tendency to drift toward a later bedtime.
- “Secondary insomnia” resulting from a chronic inability to fall asleep for several hours after getting into bed. This may be the major sleep complaint in children and adolescents with DSWPD.
- An inability to wake up at the desired time. As a result of falling asleep so late, many children and adolescents have extreme difficulty getting up in the morning for school or other activities.
- Daytime sleepiness that can lead to academic, behavioral or social impairments, or depression. Napping and dozing off are common.
- Mood changes, including depression and anxiety.
- Chronic tardiness, poor school attendance, and, in extreme cases, dropping out of school.
- High levels of alertness in the late evening.
- Extreme difficulty shifting the sleep schedule back to an earlier time, even when motivated to do so.
What causes delayed sleep-wake phase disorder?
Scientists have developed several theories about the origins of DSWPD. Although the cause of DSWP is not completely known, it likely is an exaggerated form of the normal shift in sleep and wake times that occurs in all adolescents around the time of puberty. Children who are natural “night owls” are also more at risk to develop DSWPD. There also may be a genetic contribution to developing DSWPD — some 40 percent of those affected have a family history of the disorder — and many other factors may be potential contributors, including:
- Early morning demands. Schedule changes, such as early school start times in high school, can cause a teen to get chronically insufficient sleep.
- Late evening activities. Sports practices late in the day and caffeine consumption can lead to delayed sleep onset.
- Late-day screen exposure. Use of electronic devices, specifically those that emit blue light, like TVs, computers, smartphones, and e-readers, before bed may suppress the release of melatonin, the body's biological signal for sleep. Individuals with DSPWD may be sensitive to even low levels of evening light.
- Little early daylight. Lack of exposure to morning light (which suppresses melatonin and helps you wake up) also contributes to DSWPD.
Delayed Sleep-Wake Phase Disorder | Diagnosis & Treatment
How is delayed sleep-wake phase disorder diagnosed?
If your child seems to have symptoms suggestive of delayed sleep-wake phase disorder (DSWPD), a sleep specialist can evaluate the problem using the following techniques:
- Taking a detailed history of your child's symptoms, including any medical, mental health, or developmental issues.
- Doing a complete physical examination.
- A sleep log kept by parents, caregivers, or the child (if he or she is old enough) for several weeks. Keeping a log helps track your child's sleep patterns and amounts of sleep over an extended period of time.
- Tracking your child’s sleep patterns over two or three weeks using a wristwatch-like validated device called an actigraph.
- In rare cases, an overnight sleep study, if the sleep specialist suspects additional problems such as sleep apnea or excessive movements during sleep. (Sleep studies are unnecessary in the vast majority of patients with DSWPD.)
What are the treatments for delayed sleep-wake phase disorder?
If your child or adolescent has been diagnosed with DSWPD, there are several treatment options, depending on the severity of the problem, your child's general health, and other factors. It requires significant effort and commitment on the part of the child or adolescent. The goal of treatment is to “reset” the internal clock to a more normal schedule that is more compatible with the demands of school or work. Because DSWPD can be complex, treatment should usually be handled by a sleep medicine specialist.
Treatment of DSWPD may involve some or all of the following:
- Adjustment of sleep schedules. If your child’s sleep is delayed by less than three hours, shifting bed and wake times to earlier in the day may solve the problem. If the child is falling asleep more than three hours later than the desired bedtime, shifting bedtime and wake times two to three hours later each day may be the best option until your child reaches a target bedtime/wake time schedule.
- Light therapy. This method involves exposing your child or teen to a broad-spectrum light source (typically a light box) for a period of time each morning. We also advise avoiding melatonin-suppressing blue light, especially from screens, in the evening hours.
- Melatonin. This is a synthetic form of your body’s natural biological sleep signal. When taken late in the day, melatonin may help shift the fall asleep time earlier. The dose of melatonin and the time that it is taken are both important, so this should be discussed with your child’s provider before starting melatonin.
- Sleep hygiene. It's critical that children understand the importance of a regular sleep schedule and principles of healthy sleep, such as maintaining consistent sleep schedules on weekends and weekdays, avoiding naps and caffeine, having a bedtime routine that is calm and sleep-inducing, and turning off electronic media an hour before bedtime.