Signs and Symptoms of DSPS
Delayed sleep phase syndrome is characterized by the inability to fall asleep before early morning (i.e., midnight to 3 a.m.) and difficulty waking in the morning. Patients with DSPS usually are able to fall asleep when the body signals that it is time and sleepiness does not usually occur before this delayed period.
In some cases, instead of interfering with daily activities, DSPS may suit the individual's lifestyle. If DSPS severely interferes with an imposed schedule, subsequent stress and anxiety may cause sleep onset insomnia. If a person realizes that it is important to sleep at a certain time and attempts to sleep before the body's sleep phase occurs, severe symptoms such as excessive daytime sleepiness, fatigue, and altered eating habits may develop.
Patients with DSPS may have difficulty keeping a job that requires them to perform early in the morning and may have more success if they select a night or second shift job. Driving or operating equipment in the early morning can be dangerous.
In some cases, people with DSPS become dependent on alcohol or sedatives in an attempt to induce sleep. These substances complicate the disorder and the body's attempts to reconcile sleep-wake habits.
Studies of high school students have shown a correlation between poor performance (e.g., lower GPA) and a lack of sleep. In most cases, students who get enough sleep achieve better grades, feel more rested during the school day, and require less naptime. High-school-related stress and rapidly changing social habits may cause a disturbance in sleep and result in DSPS.
People with DSPS are often alert, ready, responsive, creative, productive, and quick at different times of the day and night. If sleep phase is accommodated by lifestyle, symptoms of the disorder do not occur.