Is this the key to the teenage brain? We are used to hearing derisive taunts about teenagers being tired and lethargic. But new science shows that school may be to blame.
Sleep more and start school later say experts

Glossary
Apprehension - Anxiety that something bad will happen.
Fatigue - Tiredness.
Chronic - A condition which recurs over time, or lasts for several years.
Insomnia - A common sleep disorder which makes it harder to fall asleep, stay asleep or get good quality sleep.
Hit the hay - To go to bed in order to sleep.
Hormone - Chemicals carried in the bloodstream that alter the way your body's systems act.