What is the difference between delayed sleep phase syndrome and sleep wake rhythm?

I am confused between DSPS and irregular sleep wake rhythm. I don’t know which of these two sleep disorders I have. I can never sleep unless it’s past midnight, usually a few hours later, and then I wake around 10am-11am. Then I gradually fall asleep again around 3pm-6pm. Can you help me? I don’t have brain damage or other neurological disorders so what could I possibly have?

Doctors Answers (3)

Richard J. Schumann Jr., MD
Answered on: 6/1/2012 1

The non 24 hour sleep wake disorder pattern is characterized by a steady pattern consisting of progressive delays in sleep and wake times. Most of the individual with this disorder are blind, and the absence of light stimuli in the suprachismatic nucleus-(biologic time clock) results in a progressive delay in the circadian rhythyms. In Delayed sleep phase syndrome (DSPS), the circadian rhythms are shifted to a later than normal clock time. Patients are usually unable to fall asleep until later than normal 2-4 AM. There is usually no proble maintaining sleep, and when undisturbed the sleep time is of normal length. Chronotherapy (progressive increae in sleep time) and bringht light therapy (usually in early AM) are the usual methods of treatment will help phase advance patients with DSPS.

Syed Nabi, M.D.
Answered on: 5/29/2012

DSPS is delayed sleep phase syndrome. typically the entire sleep-wake is shifted to the point that people go to bed later than "enviornment" and wake up later than other people. WIth irregular sleep rhythm there is no well established rhythm.. It is best to consult with a physician who can help you figure out the underlying rhythm and make a plan for your management.

J. Douglas Hudson, MD, DABSM
Answered on: 5/25/2012

Your falling asleep after midnight and sleeping several hours and awakening at 10-11 AM is generally considered to be DSPS. The falling asleep in the afternoon (for how long?) may be secondary to sleep deprivation if your prior sleep was insufficient (either in quantity or quality). How sleepy are you during the day? A sleep study would be helpful in answering the question. You will need to find a sleep lab that can accommodate your sleep time. The lab can then recommend a physician whom you should see who can order the study. Sometimes, the sleep physician can correct the problem to a point that a "regular" sleep study (10 PM to 6AM) could be performed.