Delayed phase sleep syndrome is a sleep disorder that delays a person’s sleep-wake cycle by two or more hours. People with this disorder have trouble falling asleep and waking up, even if they use sleep aids such as sleeping pills. For most people, the sleeping trouble begins at adolescence; when the problem is of adult onset, it often is associated with depression. Delayed phase sleep syndrome is also called delayed sleep phase syndrome or DSPS.
The two defining symptoms of delayed phase sleep syndrome are an inability to fall asleep at the desired time and, as a consequence, an inability to wake up promptly in the morning. For example, someone might have an external schedule that requires sleeping from 10 p.m. until 6 a.m. but have an internal body-clock that will not allow them to fall asleep until 1 a.m. As a result, he or she loses several hours’ sleep, has trouble waking up and is drowsy during the day. People with this syndrome tend to perform poorly at work or school and have increasing difficulty functioning during the day because of the loss of sleep.
There are several modes of treatment for delayed phase sleep syndrome. All of these treatments require that the patient puts a large amount of effort into improving his or her sleeping habits. Consistency is also very important to help the body move to an improved sleep-wake cycle and maintain the improvement. Treatment generally will involve at least two of the following: sleep hygiene therapy, shifting the person's internal clock and bright-light therapy.
In sleep hygiene therapy, the patient learns about good sleeping habits and how he or she can improve sleep quality. Good sleeping habits include going to bed and getting up at the same time every day; avoiding caffeine, tobacco, alcohol and other drugs; and avoiding stimulating activities before bed. A comfortable bedroom environment and a calming bedtime routine also can help ease the mind and body into sleep.
A second mode of therapy for delayed phase sleep syndrome involves shifting the person’s internal clock to a time that is more conducive to sleep. This involves changing the patient’s sleep time gradually, often over a period of weeks. In phase advancement, the patient goes to bed progressively earlier, until he or she is going to bed at the desired time. In phase delay, the patient goes to bed later and later each night, until the desired bedtime is achieved.
The third type of treatment is called bright-light therapy. In this treatment, the patient uses a light box to expose themselves to bright light every morning after they wake up. A 20- to 30-minute exposure to bright light helps reset the internal clock by helping the body recognize external sleep-wake cycle cues. As an accompaniment to this treatment, the patient must avoid bright light at night, especially before bed.
