It's one of those signs you don't have to look hard to see. A person's eyes show the effects of the drugs their on. If you think your child is experimenting with drugs, watch his or her eyes. If so, there's a real good chance your child is using drugs. Any of these things should be a warning sign to you that your child could be experimenting with drugs.
Teens tend to be either very good at covering things up.
If you start wondering whether or not your child is telling you the truth there is a good chance that your instincts are right and they aren't. Be persistent and learn what it is that they are trying to cover up. This is often confused with 'normal' teenage behavior, but it can also be an obvious sign of drug abuse. Don't simply write it off. Excessive money spending or money disappearing Drugs cost money.