Circadian Rhythm Sleep-Wake Disorder, Non-24-Hour Sleep-Wake Type

Primer

Circadian Rhythm Sleep-Wake Disorder, Non-24-Hour Sleep-Wake Type is a circadian rhythm sleep-wake disorder characterized by symptoms of insomnia or excessive sleepiness due to abnormal synchronization between the 24-hour light-dark cycle and the individual's endogenous circadian rhythm. Non-24-hour sleep-wake type is most common among individuals who are blind, are visually impaired, or have decreased light perception.

Epidemiology
  • The prevalence in the general population is unclear, but is rare in sighted individuals.[1]
  • The prevalence in blind individuals is estimated to be as high as 50%.[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

Non-24-hour sleep-wake type specifier

Specify whether:

  • Non-24-hour sleep-wake type: A pattern of sleep-wake cycles that is not synchronized to the 24-hour environment, with a consistent daily drift (usually to later and later times) of sleep onset and wake times.

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

Psychotherapy

Pharmacotherapy

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) American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders (5th ed.). Arlington, VA.