Night Owls & Morning Larks

 Those suffering from advanced sleep phase syndrome (ASPS) and delayed sleep phase syndrome (DSPS) sleep and wake at inconvenient times. Individuals with ASPS sleep earlier than their desired clock time, while DSPS sufferers find sleep elusive for hours after their desired clock time. Trying to sleep when their bodies are alert, or rise when their bodies are sleepiest, can lead to insomnia or excessive daytime sleepiness. Individuals may rely on sleeping pills or alcohol to manipulate their sleep schedules.

DSPS patients may appear to be suffering from insomnia, especially if they insist on trying to sleep at a "normal" bedtime. One distinguishing characteristic is that in other types of insomnia, sleep problems include that of maintaining sleep throughout the night. DSPS sufferers have no problem sleeping...if they observe their own schedules. Another distinction is that most chronic insomniacs experience a variability in their nighttime experiences. This is not the case for DSPS patients. Treatment of DSPS requires "resetting" the biological clock by using bright light exposure, medication or chronotherapy. Chronotherapy involves delaying bedtime by three hours progressively each day until the desired bedtime is reached.

Although difficult to accomplish, this approach can work if individuals can alter their schedules daily and protect their sleep from interruptions. Exposure to bright light early in the morning (six to nine a.m.) induces a phase advance, leading to an earlier sleep onset that evening. However, patients must avoid bright light exposure during the evening as this would tend to delay sleep onset. Medication is another option: Hypnotics and melatonin may help, but many questions remain about their duration of use and the long-term safety of melatonin.

ASPS may be confused with depression. While ASPS appears to be a rare condition, it is more common in seniors. Complaints of difficulty staying awake in evening social situations are one marker of ASPS. Insomnia at the end of the sleep period is another.

Treatment for ASPS includes bright light therapy and chronotherapy. The three-hour phase advancement of chronotherapy is implemented every other day. The bright light exposure is scheduled for late afternoon or evening.