Experienced Mayo Clinic sleep specialists can help people with delayed sleep phase (DSP) become more in sync with external schedules to reduce the condition's effects.
When someone with this "night owl" internal sleep schedule can adjust his or her external schedule to accommodate it, DSP doesn't cause problems. School, recreation and work schedules, however, often collide with DSP, and if adjustments aren't made, sleep deprivation is likely to result.
Sleep deprivation can, in turn, affect concentration and learning, and also lead to significantly impaired driving.
DSP needs to be differentiated from normal variations of sleep and from other sleep disorders. In addition to taking a medical history, doctors may use a variety of tools to gather information about a patient's sleep patterns. Read more about delayed sleep phase diagnosis.
Mayo Clinic sleep specialists can help a patient assess behavioral and environmental factors that are making DSP worse, and develop a plan to correct them. A plan might include improving sleep hygiene, chronotherapy, bright light therapy or melatonin supplements. Read more about delayed sleep phase treatment options.
DSP is a circadian rhythm (internal clock) disorder. People with DSP have a sleep pattern that is delayed by two or more hours from what's considered "normal," leading to later bedtimes and wake times. DSP is more common in adolescents than in the general population.
When people with DSP are allowed to follow their natural schedules, they get sufficient sleep. But because these schedules often don't match school or work schedules, they may get insufficient sleep when trying to maintain a more conventional schedule, resulting in excessive daytime sleepiness, fatigue, and related problems. In such situations, the condition becomes a disorder.