Delayed Sleep Phase Syndrome (DSPS) is a fairly common disorder of sleep timing. People with DSPS tend to fall asleep very late, and also have difficulty waking up in time for normal work, school, or social activities.
Main Symptoms Of DSPS
What Causes DSPS ?
- DSPS causes sleep–onset insomnia. Often, DSP individuals report that they cannot sleep until early in the morning. Unlike most other insomniacs, however, they fall asleep at about the same time every night, no matter what time they go to bed.
- Unless they have another untreated sleep disorder (such as sleep apnea) in addition to DSPS, patients can sleep well, and have a normal need for sleep. Therefore, they find it very difficult to wake up in the morning if they have only slept for a few hours. However, they sleep soundly, wake up spontaneously, and do not feel sleepy again until their next “Night”, if they are allowed to follow their own late schedule, e.g. sleeping from 4:00 a.m. to noon.
- Symptoms have been present for at least a month, and usually much longer.
DSPS is believed to be a disorder of the body’s timing system–the biological clock. DSP patients have difficulty falling asleep and difficulty waking because their biological clocks are out of phase with the sleeping and waking time they try to carry out. DSPS is similar to jet lag, but much longer lasting. It can develop suddenly or gradually. You have probably heard of a biological clock which governs growth, reproductive cycles, and aging. There are also bodily rhythms, known as circadian rhythms, which are also controlled by a biological clock and which work on a daily time scale. You might have already noticed, in yourself or in others, that sleepiness doesn’t just keep increasing as it gets later.
DSPS doesn’t bother everyone who has it. Some people are happy and healthy with a late sleeping schedule, and have found ways to adjust their lifestyle to it. For this reason, many researchers consider DSPS to be a “Disorder” only when it interferes with the individual’s work or social functioning.
Keeping a Sleep Log
- You should start to keep a sleep log so a doctor can evaluate your symptoms. You should write down:
- The time you tried to fall asleep.
- The time you think you fell asleep.
- Any night–time awakenings.
- The time you wake up.
- The time you got out of bed.
- The time you had to be up.
- Whether you got up by yourself, by an alarm clock, or because you were disturbed.