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.
