Drug addiction symptoms or behaviors include, among others:

 use the drug regularly — daily or even several times a day

Having intense urges for the drug that block out any other thoughts

Over time, needing more of the drug to get the same effect

Taking larger amounts of the drug over a longer period of time than you intended

Making certain that you maintain a supply of the drug

Spending money on the drug, even though you can't afford it

Not meeting obligations and work responsibilities, or cutting back on social or recreational activities because of drug use

Continuing to use the drug, even though you know it's causing problems in your life or causing you physical or psychological harm

Doing things to get the drug that you normally wouldn't do, such as stealing

Driving or doing other risky activities when you're under the influence of the drug

Spending a good deal of time getting the drug, using the drug or recovering from the effects of the drug

Failing in your attempts to stop using the drug

Experiencing withdrawal symptoms when you attempt to stop taking the drug.

Recognizing unhealthy drug use in family members.

Sometimes it's difficult to distinguish normal teenage moodiness or angst from signs of drug use. Possible indications that your teenager or other family member is using drugs include:

Problems at school or work — frequently missing school or work, a sudden disinterest in school activities or work, or a drop in grades or work performance

Physical health issues — lack of energy and motivation, weight loss or gain, or red eyes

Neglected appearance — lack of interest in clothing, grooming or looks

Changes in behavior — exaggerated efforts to bar family members from entering his or her room or being secretive about where he or she goes with friends; or drastic changes in behavior and in relationships with family and friends

Money issues — sudden requests for money without a reasonable explanation; or your discovery that money is missing or has been stolen or that items have disappeared from your home, indicating maybe they're being sold to support drug use.