New information about adolescent sleep.

BIOLOGIC CHANGES LEADING TO SLEEP CHANGES About the time that puberty starts, adolescents develop a 2-hour sleep-wake “phase delay.” This means that if your child usually went to bed at 8 PM and woke up at 6 AM, then during adolescence he or she may feel more awake in the evening so that he or she does not feel like he or she has to go to bed until around 10 PM. Since most adolescents still have to get up early each morning for school, this delay in bedtime may lead to your adolescent getting less sleep each night than he or she did as a child.