What are some signs of sleep deprivation in my teenager?

This can be a difficult group to understand sleep deprivation since they tend to keep such odd hours to begin with.

First you can look for erratic or overemotional behavior (other than what is usual for your teenager). They might have a tendency not to act like themselves. They can lose interest in activities that they once enjoyed and may not be as social as they once were.  Finally, check to see if they are napping a great deal or falling asleep in school.