Advanced sleep-phase syndrome is a disorder in which the major sleep episode is advanced in relation to the desired clock time, resulting in symptoms of compelling evening sleepiness, an early sleep onset, and an awakening that is earlier than desired.
Advanced sleep-phase syndrome is marked by a person's intractable and chronic inability to delay the onset of evening sleep or extend sleep later into the morning hours by enforcing more conventional social sleep and wake times. The major presenting complaint may concern either the inability to stay awake in the evening, or early morning awakening insomnia, or both. Unlike other sleep maintenance disorders, the early morning awakening occurs after a normal amount of otherwise undisturbed sleep. In pure cases, there is no major mood disturbance during the waking hours. Unlike in other cases of excessive sleepiness, daytime school or work activities are not affected by somnolence. However, evening activities are routinely curtailed by the need to retire much earlier than the social norm. Typical sleep-onset times are between 6 p.m. and 8 p.m., and no later than 5 a.m. These sleep-onset and wake times occur despite the patient's best efforts to delay sleep to later hours.
Negative personal or social consequences may occur due to leaving activities in the early to mid-evening hours in order to go to sleep. Attempts to delay sleep onset to a time later than usual may result in falling asleep during social gatherings, or may have more serious consequences, such as drowsiness or falling asleep while driving in the evening. Afflicted individuals who attempt to work evening or night shifts would presumably have marked difficulty staying awake during the evening and early morning hours. If patients are chronically forced to stay up later for social or vocational reasons, the early-wakening aspect of the syndrome could lead to chronic sleep deprivation and daytime sleepiness or napping.
Back to Other Disorders page