Many DSPS patients report that their difficulties began after a period of late night studying or partying, or after employment on the evening or night shift. Following these activities, they found it impossible to sleep on a normal schedule even when they resumed normal work or school hours. Adolescence appears to be the most common period of life for the onset of DSPS, but childhood cases have been reported. It is rare for it to begin after age 30. In adolescents, failure to cooperate with a plan to reschedule the patient's sleep may be a sign of clinical depression.
Adolescence seems to be a particularily vulnerable life stage for the development of the syndrome.
Bright light therapy takes total control of light and dark exposure across the whole day. The patient uses bright light exposure early in the morning and avoids light in the evening. This should produce a phase advance. Inc. Hughes Lighting Technologies LifeLite Chronotherapy Chronotherapy is a behavioral technique in which bedtime is systematically delayed, which follows the natural tendency of human biology. Bedtime is delayed by 3 hour increments each day, establishing a 27-hour day.