Delayed sleep phase syndrome
Delayed sleep phase syndrome (DSPS) is a sleep disorder in which the patient's internal body clock is not in sync with the morning-rise evening-sleep pattern of the majority of adults. A growing body of evidence suggests that the problem is genetic, and may be inherited. Delayed sleep phase syndrome causes sleep-onset insomnia, here, sufferers report that
they cannot sleep until early morning. Unlike most other insomniacs, however, they fall asleep at about the same time every night, no matter what time they go to bed.
Delayed sleep phase syndrome results from a desynchronization between the patient's internal biological clock and the external environment. Delayed sleep phase syndrome is believed to be a disorder of the body's timing system. These persons have difficulty falling asleep and difficulty waking because their biological clocks are out of phase with the sleeping and waking times they try to carry out. Delayed sleep phase syndrome is therefore very similar to jet lag, but much longer-lasting. It can develop suddenly or gradually. The delayed sleep phase syndrome patients are usuall perplexed that they cannot find a way to fall asleep more quickly. Their efforts to advance the timing of sleep onset such as going to bed early, having a friend or family member get them us in the morning, trying relaxation techniques or using sleeping pills is not permanently successful.
They often describe sleeping pills in normal doses as having little or no effect in helping them fall asleep. Sometimes the pills only aggravate the daytime symptoms of difficulty awakening and sleepiness. Delayed sleep phase syndrome patients typically are "owls" or "night people" and say they feel and function best and are more alert during the late evening and night hours. If a sleep-wake log is kept, it usually shows a pattern of bedtime later than 2 a.m., few or no awakenings once they fall asleep, shorter sleep periods during the work/school week and lengthy (9-12 hour) sleeps with late morning to mid-afternoon wake up times on the weekend. Depression or other psychiatric problems are present in about half of the adult delayed sleep phase syndrome patients, which is about the same for people that suffer from other forms of insomnia.
Treatment for delayed sleep phase syndrome is aimed at rephasing the patient's circadian rhythm and sleep pattern. The ultimate goal is to synchronize the sleep pattern to the demands of lifestyle, school, and employment and to allow the patient to wake up at a given time feeling refreshed and functional. Treatments include light therapy with a full spectrum lamp set on a timer, and chronotherapy. These can have marked success with some patients. For other patients, acupuncture may be a solution. Several treatments may be necessary before results are seen, and the treatment is not a cure, only a way to manage the condition. Others are less fortunate – for many there is no cure and social and work patterns must either be adjusted to accommodate or the physical and mental penalties outlined above must be paid. Treatment with melatonin taken 30 minutes to an hour before bedtime may be helpful in establishing a pattern "gone awry", but has limited effect on a pattern that is healthy, albeit out-of-sync. Too high a dose of melatonin may have the unintended effect of disturbing the sleep or even causing nightmares, and uncontrollable yawning the next day.