National Sleep Foundation

Chapter 5: Circadian Rhythm Sleep Disorders

Etiology/Risk Factors

What are the risk factors for delayed sleep phase disorder (DSPD)?

The etiology of DSPD is unknown although several mechanisms have been proposed. Later sleep and wake times may result from an alteration in the endogenous circadian system but are also governed by the individual’s behavior, environment, and exposure to societal pressure.1

There is evidence for a genetic basis (circadian clock gene polymorphisms)2 that can also be familial (autosomal dominant inheritance).3 Studies have also demonstrated an association between DSPD and mood and personality disorders.4


  1. Takahashi Y, Hohjoh H, Matsuura K. Predisposing factors in delayed sleep phase syndrome. Psychiatry Clin Neurosci. 2000;54:356-358.
  2. Ebisawa T, Uchiyama M, Kajimura N, et al. Association of structural polymorphisms in the human period3 gene with delayed sleep phase syndrome. EMBO Rep. 2001;2:342-346.
  3. Ancoli-Israel S, Schnierow B, Kelsoi J, et al: A pedigree of one family with delayed sleep phase syndrome. Chronobiol Int. 2001;18:831-840.
  4. Borbely AA. A two-process model of sleep regulation. Hum Neurobiol. 1982;1:195-204.