Several studies have shown that adolescents are not getting nearly enough sleep that a growing mind needs. This has been a downward trend since the 90's, with only 25% of people aged 16 (typically a junior in high school) thinking they get enough sleep. Why let this continue? Another study has stated that "Cognitive slowing occurs in subject-paced tasks, while timepressure increases cognitive errors". We live in an increasingly test happy nation, and being unable to focus could mean failure. It's not like students are only rarely not getting enough sleep. This is a day in and day out, 11PM-5:30AM occurence.
https://www.med.upenn.edu/uep/user_documents/dfd3.pdf
http://pediatrics.aappublications.org/content/early/2015/02/10/peds.2014...