Circadian Rhythm Sleep-Wake Disorder, Delayed Sleep Phase Type

Circadian Rhythm Sleep-Wake Disorder, Delayed Sleep Phase Type (also known as Delayed Sleep Phase Syndrome [DSPS]) is a circadian rhythm sleep-wake disorder characterized by a delay in the timing of the major sleep period (usually more than 2 hours) in relation to the desired sleep and wake-up time, resulting in symptoms of insomnia and excessive sleepiness.[1]

  • The prevalence is as high as 7% of adolescents
  • It is much lower in the general population, around 0.17%[2]
Risk Factors
Criterion A

A persistent or recurrent pattern of sleep disruption that is primarily due to an alteration of the circadian system or to a misalignment between the endogenous circadian rhythm and the sleep-wake schedule required by an individual’s physical environment or social or professional schedule.

Criterion B

The sleep disruption leads to excessive sleepiness or insomnia, or both.

Criterion C

The sleep disturbance causes clinically significant distress or impairment in social, occupational, and other important areas of functioning.

Delayed sleep phase type specifier

Specify whether:

  • Delayed sleep phase type: A pattern of delayed sleep onset and awakening times, with an inability to fall asleep and awaken at a desired or convention ally acceptable earlier time.
    • Specify if:
      • Familial: A family history of delayed sleep phase is present.
    • Specify if:
      • Overlapping with non-24-hour sleep-wake type: Delayed sleep phase type may overlap with another circadian rhythm sleep-wake disorder, non-24-hour sleep-wake type.

Length Specifier

Specify if:

  • Episodic: Symptoms last at least 1 month but less than 3 months.
  • Persistent: Symptoms last 3 months or longer.
  • Recurrent: 2 or more episodes occur within the space of 1 year.
  • Limit light exposure at night, maintain consistent sleep-wake schedule
  • Early morning exposure to 10000 lux for 30 minutes.[4]
For Patients
For Providers