Delayed sleep phase syndrome (DSPS) commonly starts in adolescence as it is thought to be related to the surge of testosterone in young people. It is commonly seen in young men but I do come across young women with the same problem as well in my clinical practice. This is not surprising as women also have androgens in their body. In delayed sleep phase syndrome, the individual would sleep late and wake up late.
Typically, they sleep at 2-4 am, and then wake up 6-8 hours later. In terms of sleep duration and sleep quality, they are okay; the main problem is the timing of their sleep. The basic problem is that their biological clock is out of sync with the external environment.
The common problems DSPS sufferers experience include: challenges with schooling and work as they are not able to get out of bed at 6 or 7 am; social isolation as their friends' sleeping pattern would be different from theirs; depression which could be a result of the difficulty in maintaining friendship and a meaningful relationship.
Treatment for DSPS include light therapy and chronotherapy. Light therapy involves exposure to bright light in the morning. Chronotherapy involves trying to modify the sleeping time by shifting it so that it can eventually fit into the patient's lifestyle and commitments. It will be good to seek treatment from a doctor who has experience in helping patients with circadian rhythm sleep disorders.