It’s not always easy to tell when teens are using drugs, because many signs or symptoms are common for youth this age. While there is no single warning sign for drug or alcohol use, some signs to look for include:

• Skipping classes or not doing well in school
• Unusual odors on their clothes or in their room
• Hostility or lack of cooperation
• Physical changes (red eyes, runny nose)
• Borrowing money often, or suddenly having extra cash
• Lack of interest in activities
• Significant mood changes
• Bottles of eye drops, which may be used to mask bloodshot eyes or dilated pupils
• New use of mouthwash or breath mints to cover up the smell of alcohol
• Loss of interest in personal appearance
• Change in friends
• Heightened secrecy about actions or possession
• Missing prescription drugs

​
Information retrieved from Office of National Drug Control Policy and the National Youth Anti-Drug Media Campaign