Circadian Rhythm Sleep-Wake Disorder, Delayed Sleep Phase Type

Primer

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]

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

Diagnostic Criteria

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.

Specifier Criteria

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

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.

Signs and Symptoms

Screening and Rating Scales

Pathophysiology

Differential Diagnosis

Investigations

Physical Exam

Treatment

Behavioural

  • Limit light exposure at night, maintain consistent sleep-wake schedule

Pharmacological

Light therapy

  • Early morning exposure to 10000 lux for 30 minutes.[4]

Guidelines

Resources

For Patients
For Providers
Articles
Research

References

1) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.
2) Nesbitt, A. D. (2018). Delayed sleep-wake phase disorder. Journal of thoracic disease, 10(Suppl 1), S103.
3) van Geijlswijk, I. M., Korzilius, H. P., & Smits, M. G. (2010). The use of exogenous melatonin in delayed sleep phase disorder: a meta-analysis. Sleep, 33(12), 1605-1614.
4) Figueiro, M. G. (2016). Delayed sleep phase disorder: clinical perspective with a focus on light therapy. Nature and science of sleep, 8, 91.