National Sleep Foundation

Chapter 5: Circadian Rhythm Sleep Disorders

Assessment and Diagnosis

Assessment and diagnosis of delayed sleep phase disorder (DSPD)

All circadian rhythm sleep disorders require a similar clinical assessment that includes a complete sleep history.

Analysis of the patient’s sleep-wake schedule for at least a week (and preferably for 14 days), using a sleep log and/or actigraph, should be used to identify a delay in the timing of the habitual sleep period. Polysomnography can also be used to assess DSPD and rule out stress and other sleep disorders, such as sleep apnea16.

Dim light melatonin onset (DLMO) may also be used to diagnose DSPD, assessed by melatonin measurements taken from saliva or plasma. Patients with DSPD have DLMO times occurring after 10:00 pm17.

Diagnosis of DSPD is “usually made on the basis of the patient’s history of chronic or recurrent complaints of symptoms of insomnia due to a stable delay in the timing of the major sleep and wake period18. 

References

16. Reid KJ and Zee PC. “Circadian disorders of the sleep-wake cycle,” in Kryger M, Roth T, Dement W (ed.), Principles and Practice of Sleep Medicine (5th Edition), St. Louis: Elsevier Saunders, 2011, pages 470-482.

17. Reid KJ and Zee PC. “Circadian disorders of the sleep-wake cycle,” in Kryger M, Roth T, Dement W (ed.), Principles and Practice of Sleep Medicine (5th Edition), St. Louis: Elsevier Saunders, 2011, pages 470-482. 

18. Reid KJ and Zee PC. “Circadian disorders of the sleep-wake cycle,” in Kryger M, Roth T, Dement W (ed.), Principles and Practice of Sleep Medicine (5th Edition), St. Louis: Elsevier Saunders, 2011, pages 470-482.