There are some signs you might be able to see. If someone is high on marijuana, he or she might:

• seem silly and giggly for no reason;
• have very red, bloodshot eyes; and
• have a hard time remembering things that just happened.

When the early effects fade, over a few hours, the user can become very sleepy.

Parents should be aware of changes in their child’s behavior, although this may be difficult with teenagers. Parents should look for withdrawal, depression, fatigue, carelessness with grooming, hostility, and deteriorating relationships with family members and friends. In addition, changes in academic performance, increased absenteeism or truancy, lost interest in sports or other favorite activities, and changes in eating or sleeping habits could be related to drug use. However, these signs may also indicate problems other than use of drugs.

In addition, parents should be aware of:

• signs of drugs and drug paraphernalia, including pipes and rolling papers
• odor on clothes and in the bedroom
• use of incense and other deodorizers
• use of eye drops
• clothing, posters, jewelry, etc., promoting drug use