Delayed sleep phase disorder

chronic mismatch between a person's normal daily rhythm, compared to other people and societal norms

Delayed sleep phase disorder is a circadian rhythm sleep disorder.[1] It affects the timing of sleep. It has an effect on the time when a person is most alert during the day. It also affects core body temperature rhythm and other daily rhythms. People with DSPD generally fall asleep after midnight. They have difficulty waking up in the morning.[2] Affected people usually have normal need for sleep. This condition usually develops in childhood or adolescence. DSPD is a life-long condition.


  1. Mayo Clinic Staff (16 July 2014). "Delayed sleep phase". Mayo Clinic. Retrieved 13 September 2014.
  2. Stanley J. Swierzewski, III, M.D. (1 Dec 2000). "DSPS Overview, Incidence and Prevalence". Remedy Health Media, LLC. Retrieved 13 September 2014.{{cite web}}: CS1 maint: multiple names: authors list (link)