Moodiness. Difficulty concentrating. Forgetfulness. Irritability. Poor judgment. Sound like a preteen or teen you know? Probably, but these aren't universal symptoms of adolescence. More likely, they're signs that your child is sleep-deprived. At puberty, kids' sleep needs actually increase. Tweens and teens need at least 9.5 hours of sleep, and preferably ten. Most teens in the U.S. are endangering...