Delayed sleep phase disorder

In Delayed Sleep Phase Disorder (DSPD) sleep tends to come two or three hours, or more, later than the conventional time. For example, the person’s optimum sleep period might come between 2:00am and 10:00am. Consequently, the person is likely to struggle to get to school or work on time – or has to get up before they are fully rested and therefore go through life on less sleep than is needed. A degree of sleep delay is common in adolescents but most people grow out of it in their early 20s.