Delayed Sleep-Wake Phase Disorder | Symptoms & Causes

Delayed sleep-wake phase disorder (DSWPD) usually develops during adolescence but can start in childhood. Symptoms of this disorder can mimic those of other medical problems, and careful evaluation by a healthcare provider is critical.

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.
  • Inattentiveness.
  • 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. Allthough 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) 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.

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