Adolescents and teenagers require 8 to 10 hours of sleep each night to support brain development, an amount of time that is challenging for them to achieve when the school day begins early in the morning. Now, California has become the first state in the country to require schools to start later. Middle schools must start no earlier than 8am and high schools no earlier than 8:30 AM. For our back to school series, "School Principles," we explore the issue of sleep deprivation for students, how it affects school performance, and the impact on later start times on schools and families.

To understand the value of this legislation, we spoke with Lisa L. Lewis, author of “The Sleep Deprived Teen: Why Our Teenagers are So Tired, And How Parents and Schools Can Help Them Thrive.” We also spoke with Dr. Marian Kim-Phelps, Superintendent of Poway Unified School District about the challenges of implementing these mandated changes.